Refactor truststore merger logic

- Merge PemTruststore and JavaTruststore into Truststore
- Rename controller classes to be consistent
- Remove duplicated methods

Issue-ID: DCAEGEN2-2253
Signed-off-by: Piotr Marcinkiewicz <piotr.marcinkiewicz@nokia.com>
Change-Id: I3270cd9811e5eaf360ceea0d0ca99be1155eaf00

29 files changed, 265 insertions, 415 deletions

diff --git a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/TrustStoreMerger.java b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/TrustStoreMerger.java
index babd32e2..7f53331f 100644
--- a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/TrustStoreMerger.java
+++ b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/TrustStoreMerger.java
@@ -22,12 +22,9 @@ package org.onap.oom.truststoremerger;
 import java.util.List;
 import org.onap.oom.truststoremerger.api.ExitStatus;
 import org.onap.oom.truststoremerger.api.ExitableException;
-import org.onap.oom.truststoremerger.certification.file.TruststoreFileFactory;
-import org.onap.oom.truststoremerger.certification.file.TruststoreFilesListProvider;
-import org.onap.oom.truststoremerger.certification.file.model.Truststore;
-import org.onap.oom.truststoremerger.certification.file.provider.FileManager;
-import org.onap.oom.truststoremerger.certification.file.provider.PasswordReader;
-import org.onap.oom.truststoremerger.certification.file.provider.entry.CertificateWithAlias;
+import org.onap.oom.truststoremerger.merger.TruststoreFilesProvider;
+import org.onap.oom.truststoremerger.merger.model.Truststore;
+import org.onap.oom.truststoremerger.merger.model.certificate.CertificateWithAlias;
 import org.onap.oom.truststoremerger.configuration.MergerConfigurationProvider;
 import org.onap.oom.truststoremerger.configuration.model.MergerConfiguration;
 import org.onap.oom.truststoremerger.configuration.path.DelimitedPathsReader;
@@ -69,8 +66,9 @@ class TrustStoreMerger {
         baseFile.createBackup();
 
         for (int i = SECOND_TRUSTSTORE_INDEX; i < truststoreFilesList.size(); i++) {
-            List<CertificateWithAlias> certificateWrappers = truststoreFilesList.get(i).getCertificates();
-            baseFile.addCertificate(certificateWrappers);
+            Truststore truststore = truststoreFilesList.get(i);
+            List<CertificateWithAlias> certificateWrappers = truststore.getCertificates();
+            baseFile.addCertificates(certificateWrappers);
         }
 
         baseFile.saveFile();
@@ -87,13 +85,9 @@ class TrustStoreMerger {
         return factory.createConfiguration();
     }
 
-    private List<Truststore> getTruststoreFiles(MergerConfiguration configuration) throws ExitableException {
-        TruststoreFileFactory truststoreFileFactory = new TruststoreFileFactory(new FileManager(),
-            new PasswordReader());
-        TruststoreFilesListProvider truststoreFilesListProvider = new TruststoreFilesListProvider(
-            truststoreFileFactory);
-        return truststoreFilesListProvider
-            .getTruststoreFilesList(
+    private static List<Truststore> getTruststoreFiles(MergerConfiguration configuration) throws ExitableException {
+        return TruststoreFilesProvider
+            .getTruststoreFiles(
                 configuration.getTruststoreFilePaths(),
                 configuration.getTruststoreFilePasswordPaths()
             );
diff --git a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/api/CertificateConstants.java b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/api/CertificateConstants.java
index 68c5d13c..75756aa1 100644
--- a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/api/CertificateConstants.java
+++ b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/api/CertificateConstants.java
@@ -21,8 +21,8 @@ package org.onap.oom.truststoremerger.api;
 
 public class CertificateConstants {
 
-    public static final String JKS_INSTANCE = "JKS";
-    public static final String PKCS12_INSTANCE = "PKCS12";
+    public static final String JKS_TYPE = "JKS";
+    public static final String PKCS12_TYPE = "PKCS12";
     public static final String X_509_CERTIFICATE = "X.509";
     public static final String BOUNCY_CASTLE_PROVIDER = "BC";
 
diff --git a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/TruststoreFileFactory.java b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/TruststoreFileFactory.java
deleted file mode 100644
index d93409b6..00000000
--- a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/TruststoreFileFactory.java
+++ /dev/null
@@ -1,99 +0,0 @@
-/*============LICENSE_START=======================================================
- * oom-truststore-merger
- * ================================================================================
- * Copyright (C) 2020 Nokia. All rights reserved.
- * ================================================================================
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- * ============LICENSE_END=========================================================
- */
-
-package org.onap.oom.truststoremerger.certification.file;
-
-import org.onap.oom.truststoremerger.certification.file.model.JavaTruststore;
-import org.onap.oom.truststoremerger.certification.file.model.PemTruststore;
-import org.onap.oom.truststoremerger.certification.file.model.Truststore;
-
-import java.io.File;
-import org.onap.oom.truststoremerger.certification.file.exception.KeystoreInstanceException;
-import org.onap.oom.truststoremerger.certification.file.exception.LoadTruststoreException;
-import org.onap.oom.truststoremerger.certification.file.exception.PasswordReaderException;
-import org.onap.oom.truststoremerger.certification.file.exception.TruststoreFileFactoryException;
-import org.onap.oom.truststoremerger.certification.file.provider.CertificateStoreControllerFactory;
-import org.onap.oom.truststoremerger.certification.file.provider.FileManager;
-import org.onap.oom.truststoremerger.certification.file.provider.JavaCertificateStoreController;
-import org.onap.oom.truststoremerger.certification.file.provider.PasswordReader;
-import org.onap.oom.truststoremerger.certification.file.provider.PemCertificateController;
-
-public class TruststoreFileFactory {
-
-    private static final String JKS_EXTENSION = ".jks";
-    private static final String P12_EXTENSION = ".p12";
-    private static final String PEM_EXTENSION = ".pem";
-    private static final String FILE_DOES_NOT_EXIST_MSG_TEMPLATE = "File: %s does not exist";
-    private static final String UNKNOWN_TRUSTSTORE_TYPE_MSG_TEMPLATE = "Unknown truststore extension type: %s";
-
-    private final FileManager fileManager;
-    private final PasswordReader passwordReader;
-    private final CertificateStoreControllerFactory certificateStoreControllerFactory =
-        new CertificateStoreControllerFactory();
-
-    public TruststoreFileFactory(FileManager fileManager, PasswordReader passwordReader) {
-        this.fileManager = fileManager;
-        this.passwordReader = passwordReader;
-    }
-
-    public Truststore create(String truststoreFilePath, String truststorePasswordPath)
-        throws TruststoreFileFactoryException, PasswordReaderException, KeystoreInstanceException, LoadTruststoreException {
-        File truststoreFile = new File(truststoreFilePath);
-        if (!fileManager.checkIfFileExists(truststoreFile)) {
-            throw new TruststoreFileFactoryException(String.format(FILE_DOES_NOT_EXIST_MSG_TEMPLATE, truststoreFile));
-        }
-        return createTypedTruststore(truststoreFile, truststorePasswordPath);
-    }
-
-    private Truststore createTypedTruststore(File truststoreFile, String truststorePasswordPath)
-        throws KeystoreInstanceException, PasswordReaderException, LoadTruststoreException, TruststoreFileFactoryException {
-        String extension = fileManager.getExtension(truststoreFile);
-        switch (extension) {
-            case JKS_EXTENSION:
-                return createJksTruststore(truststoreFile, truststorePasswordPath);
-            case P12_EXTENSION:
-                return createP12Truststore(truststoreFile, truststorePasswordPath);
-            case PEM_EXTENSION:
-                return createPemTruststore(truststoreFile);
-            default:
-                throw new TruststoreFileFactoryException(
-                    String.format(UNKNOWN_TRUSTSTORE_TYPE_MSG_TEMPLATE, extension));
-        }
-    }
-
-    private JavaTruststore createJksTruststore(File truststoreFile, String truststorePasswordPath)
-        throws PasswordReaderException, LoadTruststoreException, KeystoreInstanceException {
-        String password = passwordReader.readPassword(new File(truststorePasswordPath));
-        JavaCertificateStoreController storeController = certificateStoreControllerFactory
-            .createLoadedJksCertificateStoreController(truststoreFile, password);
-        return new JavaTruststore(truststoreFile, storeController);
-    }
-
-    private JavaTruststore createP12Truststore(File truststoreFile, String truststorePasswordPath)
-        throws LoadTruststoreException, KeystoreInstanceException, PasswordReaderException {
-        String password = passwordReader.readPassword(new File(truststorePasswordPath));
-        JavaCertificateStoreController storeController = certificateStoreControllerFactory
-            .createLoadedPkcs12CertificateStoreController(truststoreFile, password);
-        return new JavaTruststore(truststoreFile, storeController);
-    }
-
-    private PemTruststore createPemTruststore(File truststoreFile) {
-        return new PemTruststore(truststoreFile, new PemCertificateController(truststoreFile));
-    }
-}
diff --git a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/model/JavaTruststore.java b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/model/JavaTruststore.java
deleted file mode 100644
index d46fba1e..00000000
--- a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/model/JavaTruststore.java
+++ /dev/null
@@ -1,58 +0,0 @@
-/*============LICENSE_START=======================================================
- * oom-truststore-merger
- * ================================================================================
- * Copyright (C) 2020 Nokia. All rights reserved.
- * ================================================================================
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- * ============LICENSE_END=========================================================
- */
-
-package org.onap.oom.truststoremerger.certification.file.model;
-
-import java.io.File;
-import java.util.List;
-import org.onap.oom.truststoremerger.api.ExitableException;
-import org.onap.oom.truststoremerger.certification.file.provider.entry.CertificateWithAlias;
-import org.onap.oom.truststoremerger.certification.file.exception.WriteTruststoreFileException;
-import org.onap.oom.truststoremerger.certification.file.provider.JavaCertificateStoreController;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-public class JavaTruststore extends Truststore {
-
-    private static final Logger LOGGER = LoggerFactory.getLogger(JavaTruststore.class);
-    private final JavaCertificateStoreController storeController;
-
-    public JavaTruststore(File truststoreFile, JavaCertificateStoreController storeController) {
-        super(truststoreFile);
-        this.storeController = storeController;
-    }
-
-    @Override
-    public List<CertificateWithAlias> getCertificates() throws ExitableException {
-        LOGGER.debug("Attempt ro read certificates from file: {} ", this.getFile().getPath());
-        return storeController.getNotEmptyCertificateList();
-    }
-
-    @Override
-    public void addCertificate(List<CertificateWithAlias> certificates) throws ExitableException {
-        LOGGER.debug("Attempt to add certificates for saving to file");
-        storeController.addCertificates(certificates);
-    }
-
-    @Override
-    public void saveFile() throws WriteTruststoreFileException {
-        LOGGER.debug("Attempt to save file: {}", this.getFile().getPath());
-        storeController.saveFile();
-    }
-}
diff --git a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/model/PemTruststore.java b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/model/PemTruststore.java
deleted file mode 100644
index 36195267..00000000
--- a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/model/PemTruststore.java
+++ /dev/null
@@ -1,58 +0,0 @@
-/*============LICENSE_START=======================================================
- * oom-truststore-merger
- * ================================================================================
- * Copyright (C) 2020 Nokia. All rights reserved.
- * ================================================================================
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- * ============LICENSE_END=========================================================
- */
-
-package org.onap.oom.truststoremerger.certification.file.model;
-
-import java.io.File;
-import java.util.List;
-import org.onap.oom.truststoremerger.api.ExitableException;
-import org.onap.oom.truststoremerger.certification.file.provider.entry.CertificateWithAlias;
-import org.onap.oom.truststoremerger.certification.file.provider.PemCertificateController;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-public class PemTruststore extends Truststore {
-
-    private static final Logger LOGGER = LoggerFactory.getLogger(PemTruststore.class);
-    private final PemCertificateController pemCertificateController;
-
-    public PemTruststore(File truststoreFile, PemCertificateController pemCertificateController) {
-        super(truststoreFile);
-        this.pemCertificateController = pemCertificateController;
-    }
-
-    @Override
-    public List<CertificateWithAlias> getCertificates() throws ExitableException {
-        LOGGER.debug("Attempt ro read certificates from file: {}", this.getFile().getPath());
-        return pemCertificateController.getNotEmptyCertificateList();
-    }
-
-    @Override
-    public void addCertificate(List<CertificateWithAlias> certificates) throws ExitableException {
-        LOGGER.debug("Attempt to add certificates for saving to file");
-        pemCertificateController.addCertificates(certificates);
-    }
-
-    @Override
-    public void saveFile() throws ExitableException {
-        LOGGER.debug("Attempt to save file: {}", this.getFile().getPath());
-        pemCertificateController.saveFile();
-    }
-
-}
diff --git a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/provider/CertificateStoreControllerFactory.java b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/provider/CertificateStoreControllerFactory.java
deleted file mode 100644
index 66e2aed2..00000000
--- a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/provider/CertificateStoreControllerFactory.java
+++ /dev/null
@@ -1,61 +0,0 @@
-/*============LICENSE_START=======================================================
- * oom-truststore-merger
- * ================================================================================
- * Copyright (C) 2020 Nokia. All rights reserved.
- * ================================================================================
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- * ============LICENSE_END=========================================================
- */
-
-package org.onap.oom.truststoremerger.certification.file.provider;
-
-import static org.onap.oom.truststoremerger.api.CertificateConstants.JKS_INSTANCE;
-import static org.onap.oom.truststoremerger.api.CertificateConstants.PKCS12_INSTANCE;
-
-import java.io.File;
-import java.security.KeyStore;
-import java.security.KeyStoreException;
-import org.onap.oom.truststoremerger.certification.file.exception.KeystoreInstanceException;
-import org.onap.oom.truststoremerger.certification.file.exception.LoadTruststoreException;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-public class CertificateStoreControllerFactory {
-
-    private static final Logger LOGGER = LoggerFactory.getLogger(CertificateStoreControllerFactory.class);
-
-    public JavaCertificateStoreController createLoadedJksCertificateStoreController(File certFile, String certPassword)
-        throws LoadTruststoreException, KeystoreInstanceException {
-        return createLoadedCertificateStoreController(certFile, certPassword, JKS_INSTANCE);
-    }
-
-    public JavaCertificateStoreController createLoadedPkcs12CertificateStoreController(File certFile, String certPassword)
-        throws KeystoreInstanceException, LoadTruststoreException {
-        return createLoadedCertificateStoreController(certFile, certPassword, PKCS12_INSTANCE);
-    }
-
-    private JavaCertificateStoreController createLoadedCertificateStoreController(File certFile, String certPassword,
-        String instanceType)
-        throws LoadTruststoreException, KeystoreInstanceException {
-        try {
-            JavaCertificateStoreController javaCertificateStoreController = new JavaCertificateStoreController(
-                KeyStore.getInstance(instanceType), certFile, certPassword);
-            javaCertificateStoreController.loadFile();
-            return javaCertificateStoreController;
-        } catch (KeyStoreException e) {
-            LOGGER.error("Cannot initialize Java Keystore instance");
-            throw new KeystoreInstanceException(e);
-        }
-    }
-}
-
diff --git a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/model/Truststore.java b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/common/BackupCreator.java
index 153805a7..9187393e 100644
--- a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/model/Truststore.java
+++ b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/common/BackupCreator.java
@@ -17,46 +17,32 @@
  * ============LICENSE_END=========================================================
  */
 
-package org.onap.oom.truststoremerger.certification.file.model;
+package org.onap.oom.truststoremerger.common;
 
 import java.io.File;
 import java.io.FileOutputStream;
 import java.nio.file.Files;
-import java.util.List;
-import org.onap.oom.truststoremerger.api.ExitableException;
-import org.onap.oom.truststoremerger.certification.file.provider.entry.CertificateWithAlias;
-import org.onap.oom.truststoremerger.certification.file.exception.CreateBackupException;
+import org.onap.oom.truststoremerger.merger.exception.CreateBackupException;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-public abstract class Truststore {
+public final class BackupCreator {
 
-    private static final Logger LOGGER = LoggerFactory.getLogger(Truststore.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(BackupCreator.class);
     private static final String BACKUP_EXTENSION = ".bak";
-    private final File file;
 
-    Truststore(File file) {
-        this.file = file;
+    private BackupCreator() {
     }
 
-    public abstract List<CertificateWithAlias> getCertificates() throws ExitableException;
-
-    public abstract void addCertificate(List<CertificateWithAlias> certificates) throws ExitableException;
-
-    public abstract void saveFile() throws ExitableException;
-
-    public File getFile() {
-        return file;
-    }
-
-    public void createBackup() throws CreateBackupException {
+    public static void createBackup(File file) throws CreateBackupException {
         LOGGER.debug("Create backup of file: {}", file.getPath());
         String backupFilePath = file.getAbsolutePath() + BACKUP_EXTENSION;
         try (FileOutputStream fileOutputStream = new FileOutputStream(backupFilePath)) {
             Files.copy(file.toPath(), fileOutputStream);
         } catch (Exception e) {
-            LOGGER.error("Cannot create backup of file: {} ", getFile().getPath());
+            LOGGER.error("Cannot create backup of file: {} ", file.getPath());
             throw new CreateBackupException(e);
         }
+        LOGGER.debug("Backup was successfully created in: {}", backupFilePath);
     }
 }
diff --git a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/provider/FileManager.java b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/common/ExtensionResolver.java
index 12029ade..af792c48 100644
--- a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/provider/FileManager.java
+++ b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/common/ExtensionResolver.java
@@ -17,15 +17,17 @@
  * ============LICENSE_END=========================================================
  */
 
-package org.onap.oom.truststoremerger.certification.file.provider;
+package org.onap.oom.truststoremerger.common;
 
 import java.io.File;
 
-public class FileManager {
+public final class ExtensionResolver {
 
     private static final int INDEX_NOT_FOUND = -1;
 
-    public String getExtension(File file) {
+    private ExtensionResolver() {}
+
+    public static String get(File file) {
         int extStartIndex = file.getName().lastIndexOf(".");
         if (extStartIndex == INDEX_NOT_FOUND) {
             return "";
@@ -33,7 +35,7 @@ public class FileManager {
         return file.getName().substring(extStartIndex).toLowerCase();
     }
 
-    public boolean checkIfFileExists(File file) {
+    public static boolean checkIfFileExists(File file) {
         return file.exists();
     }
 
diff --git a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/provider/PasswordReader.java b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/common/PasswordReader.java
index d7da53b0..d84be5ac 100644
--- a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/provider/PasswordReader.java
+++ b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/common/PasswordReader.java
@@ -17,17 +17,21 @@
  * ============LICENSE_END=========================================================
  */
 
-package org.onap.oom.truststoremerger.certification.file.provider;
+package org.onap.oom.truststoremerger.common;
 
 import java.io.File;
 import java.io.IOException;
 import java.nio.file.Files;
-import org.onap.oom.truststoremerger.certification.file.exception.PasswordReaderException;
+import org.onap.oom.truststoremerger.merger.exception.PasswordReaderException;
+
+public final class PasswordReader {
 
-public class PasswordReader {
     private static final String COULD_NOT_READ_PASSWORD_FROM_FILE_MSG_TEMPLATE = "Could not read password from file: %s";
 
-    public String readPassword(File file) throws PasswordReaderException {
+    private PasswordReader() {
+    }
+
+    public static String readPassword(File file) throws PasswordReaderException {
         try {
             return Files.readString(file.toPath());
         } catch (IOException e) {
diff --git a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/configuration/exception/MergerConfigurationException.java b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/configuration/exception/MergerConfigurationException.java
index 90a75d91..4bdfd9f4 100644
--- a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/configuration/exception/MergerConfigurationException.java
+++ b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/configuration/exception/MergerConfigurationException.java
@@ -24,7 +24,7 @@ import org.onap.oom.truststoremerger.api.ExitableException;
 
 public class MergerConfigurationException extends ExitableException {
 
-    public MergerConfigurationException(String message) {
-        super(message, ExitStatus.MERGER_CONFIGURATION_EXCEPTION);
+    public MergerConfigurationException(String errorMessage) {
+        super(errorMessage, ExitStatus.MERGER_CONFIGURATION_EXCEPTION);
     }
 }
diff --git a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/configuration/exception/TruststoresPathsProviderException.java b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/configuration/exception/TruststoresPathsProviderException.java
index dda53e32..6089d314 100644
--- a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/configuration/exception/TruststoresPathsProviderException.java
+++ b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/configuration/exception/TruststoresPathsProviderException.java
@@ -24,7 +24,7 @@ import org.onap.oom.truststoremerger.api.ExitableException;
 
 public class TruststoresPathsProviderException extends ExitableException {
 
-    public TruststoresPathsProviderException(String message) {
-        super(message, ExitStatus.TRUSTSTORES_PATHS_PROVIDER_EXCEPTION);
+    public TruststoresPathsProviderException(String errorMessage) {
+        super(errorMessage, ExitStatus.TRUSTSTORES_PATHS_PROVIDER_EXCEPTION);
     }
 }
diff --git a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/TruststoreFilesListProvider.java b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/merger/TruststoreFilesProvider.java
index 92e3c2a8..9108fb69 100644
--- a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/TruststoreFilesListProvider.java
+++ b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/merger/TruststoreFilesProvider.java
@@ -17,37 +17,35 @@
  * ============LICENSE_END=========================================================
  */
 
-package org.onap.oom.truststoremerger.certification.file;
-
-import org.onap.oom.truststoremerger.certification.file.model.Truststore;
+package org.onap.oom.truststoremerger.merger;
 
 import java.util.ArrayList;
 import java.util.List;
-import org.onap.oom.truststoremerger.certification.file.exception.KeystoreInstanceException;
-import org.onap.oom.truststoremerger.certification.file.exception.LoadTruststoreException;
-import org.onap.oom.truststoremerger.certification.file.exception.PasswordReaderException;
-import org.onap.oom.truststoremerger.certification.file.exception.TruststoreFileFactoryException;
+import org.onap.oom.truststoremerger.merger.exception.KeystoreInstanceException;
+import org.onap.oom.truststoremerger.merger.exception.LoadTruststoreException;
+import org.onap.oom.truststoremerger.merger.exception.PasswordReaderException;
+import org.onap.oom.truststoremerger.merger.exception.TruststoreFileFactoryException;
+import org.onap.oom.truststoremerger.merger.model.TruststoreFactory;
+import org.onap.oom.truststoremerger.merger.model.Truststore;
 
-public class TruststoreFilesListProvider {
+public class TruststoreFilesProvider {
 
-    private final TruststoreFileFactory truststoreFileFactory;
 
-    public TruststoreFilesListProvider(TruststoreFileFactory truststoreFileFactory) {
-        this.truststoreFileFactory = truststoreFileFactory;
+    private TruststoreFilesProvider() {
     }
 
-    public List<Truststore> getTruststoreFilesList(List<String> truststoreFilePaths,
+    public static List<Truststore> getTruststoreFiles(List<String> truststoreFilePaths,
         List<String> truststoreFilePasswordPaths)
         throws LoadTruststoreException, PasswordReaderException, TruststoreFileFactoryException, KeystoreInstanceException {
-        List<Truststore> truststoreFilesList = new ArrayList<>();
+        List<Truststore> truststoreFiles = new ArrayList<>();
         for (int i = 0; i < truststoreFilePaths.size(); i++) {
             String truststorePath = truststoreFilePaths.get(i);
             String passwordPath = truststoreFilePasswordPaths.get(i);
 
-            Truststore truststore = truststoreFileFactory.create(truststorePath, passwordPath);
-            truststoreFilesList.add(truststore);
+            Truststore truststore = TruststoreFactory.create(truststorePath, passwordPath);
+            truststoreFiles.add(truststore);
         }
 
-        return truststoreFilesList;
+        return truststoreFiles;
     }
 }
diff --git a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/exception/AliasConflictException.java b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/merger/exception/AliasConflictException.java
index a4102d9f..71df3a45 100644
--- a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/exception/AliasConflictException.java
+++ b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/merger/exception/AliasConflictException.java
@@ -17,15 +17,15 @@
  * ============LICENSE_END=========================================================
  */
 
-package org.onap.oom.truststoremerger.certification.file.exception;
+package org.onap.oom.truststoremerger.merger.exception;
 
 import org.onap.oom.truststoremerger.api.ExitStatus;
 import org.onap.oom.truststoremerger.api.ExitableException;
 
 public class AliasConflictException extends ExitableException {
 
-    public AliasConflictException(String message) {
-        super(message, ExitStatus.ALIAS_CONFLICT_EXCEPTION);
+    public AliasConflictException(String errorMessage) {
+        super(errorMessage, ExitStatus.ALIAS_CONFLICT_EXCEPTION);
     }
 
 }
diff --git a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/exception/CreateBackupException.java b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/merger/exception/CreateBackupException.java
index a21f7013..f655a9f5 100644
--- a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/exception/CreateBackupException.java
+++ b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/merger/exception/CreateBackupException.java
@@ -17,14 +17,14 @@
  * ============LICENSE_END=========================================================
  */
 
-package org.onap.oom.truststoremerger.certification.file.exception;
+package org.onap.oom.truststoremerger.merger.exception;
 
 import org.onap.oom.truststoremerger.api.ExitStatus;
 import org.onap.oom.truststoremerger.api.ExitableException;
 
 public class CreateBackupException extends ExitableException {
 
-    public CreateBackupException(Exception e) {
-        super(e, ExitStatus.CREATE_BACKUP_EXCEPTION);
+    public CreateBackupException(Exception cause) {
+        super(cause, ExitStatus.CREATE_BACKUP_EXCEPTION);
     }
 }
diff --git a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/exception/KeystoreInstanceException.java b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/merger/exception/KeystoreInstanceException.java
index c5bcc3ca..99a955d9 100644
--- a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/exception/KeystoreInstanceException.java
+++ b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/merger/exception/KeystoreInstanceException.java
@@ -17,14 +17,14 @@
  * ============LICENSE_END=========================================================
  */
 
-package org.onap.oom.truststoremerger.certification.file.exception;
+package org.onap.oom.truststoremerger.merger.exception;
 
 import org.onap.oom.truststoremerger.api.ExitStatus;
 import org.onap.oom.truststoremerger.api.ExitableException;
 
 public class KeystoreInstanceException extends ExitableException {
 
-    public KeystoreInstanceException(Throwable e) {
-        super(e, ExitStatus.KEYSTORE_INSTANCE_EXCEPTION);
+    public KeystoreInstanceException(Exception cause) {
+        super(cause, ExitStatus.KEYSTORE_INSTANCE_EXCEPTION);
     }
 }
diff --git a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/exception/LoadTruststoreException.java b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/merger/exception/LoadTruststoreException.java
index b8bb53fa..810bf556 100644
--- a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/exception/LoadTruststoreException.java
+++ b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/merger/exception/LoadTruststoreException.java
@@ -17,14 +17,14 @@
  * ============LICENSE_END=========================================================
  */
 
-package org.onap.oom.truststoremerger.certification.file.exception;
+package org.onap.oom.truststoremerger.merger.exception;
 
 import org.onap.oom.truststoremerger.api.ExitStatus;
 import org.onap.oom.truststoremerger.api.ExitableException;
 
 public class LoadTruststoreException extends ExitableException {
 
-    public LoadTruststoreException(Throwable e) {
-        super(e, ExitStatus.TRUSTSTORE_LOAD_FILE_EXCEPTION);
+    public LoadTruststoreException(Exception cause) {
+        super(cause, ExitStatus.TRUSTSTORE_LOAD_FILE_EXCEPTION);
     }
 }
diff --git a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/exception/MissingTruststoreException.java b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/merger/exception/MissingTruststoreException.java
index c502d6b6..9065c9d3 100644
--- a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/exception/MissingTruststoreException.java
+++ b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/merger/exception/MissingTruststoreException.java
@@ -17,14 +17,14 @@
  * ============LICENSE_END=========================================================
  */
 
-package org.onap.oom.truststoremerger.certification.file.exception;
+package org.onap.oom.truststoremerger.merger.exception;
 
 import org.onap.oom.truststoremerger.api.ExitStatus;
 import org.onap.oom.truststoremerger.api.ExitableException;
 
 public class MissingTruststoreException extends ExitableException {
 
-    public MissingTruststoreException(String message) {
-        super(message, ExitStatus.MISSING_TRUSTSTORE_EXCEPTION);
+    public MissingTruststoreException(String errorMessage) {
+        super(errorMessage, ExitStatus.MISSING_TRUSTSTORE_EXCEPTION);
     }
 }
diff --git a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/exception/PasswordReaderException.java b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/merger/exception/PasswordReaderException.java
index d601d229..9f9d2e27 100644
--- a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/exception/PasswordReaderException.java
+++ b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/merger/exception/PasswordReaderException.java
@@ -17,13 +17,13 @@
  * ============LICENSE_END=========================================================
  */
 
-package org.onap.oom.truststoremerger.certification.file.exception;
+package org.onap.oom.truststoremerger.merger.exception;
 
 import org.onap.oom.truststoremerger.api.ExitStatus;
 import org.onap.oom.truststoremerger.api.ExitableException;
 
 public class PasswordReaderException extends ExitableException {
-    public PasswordReaderException(String message) {
-        super(message, ExitStatus.PASSWORD_READER_EXCEPTION);
+    public PasswordReaderException(String errorMessage) {
+        super(errorMessage, ExitStatus.PASSWORD_READER_EXCEPTION);
     }
 }
diff --git a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/exception/TruststoreDataOperationException.java b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/merger/exception/TruststoreDataOperationException.java
index cf848f79..c18cb006 100644
--- a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/exception/TruststoreDataOperationException.java
+++ b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/merger/exception/TruststoreDataOperationException.java
@@ -17,14 +17,14 @@
  * ============LICENSE_END=========================================================
  */
 
-package org.onap.oom.truststoremerger.certification.file.exception;
+package org.onap.oom.truststoremerger.merger.exception;
 
 import org.onap.oom.truststoremerger.api.ExitStatus;
 import org.onap.oom.truststoremerger.api.ExitableException;
 
 public class TruststoreDataOperationException extends ExitableException {
 
-    public TruststoreDataOperationException(Exception e) {
-        super(e, ExitStatus.TRUSTSTORE_DATA_OPERATION_EXCEPTION);
+    public TruststoreDataOperationException(Exception cause) {
+        super(cause, ExitStatus.TRUSTSTORE_DATA_OPERATION_EXCEPTION);
     }
 }
diff --git a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/exception/TruststoreFileFactoryException.java b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/merger/exception/TruststoreFileFactoryException.java
index 18349fd4..f802a9d3 100644
--- a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/exception/TruststoreFileFactoryException.java
+++ b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/merger/exception/TruststoreFileFactoryException.java
@@ -17,14 +17,14 @@
  * ============LICENSE_END=========================================================
  */
 
-package org.onap.oom.truststoremerger.certification.file.exception;
+package org.onap.oom.truststoremerger.merger.exception;
 
 import org.onap.oom.truststoremerger.api.ExitStatus;
 import org.onap.oom.truststoremerger.api.ExitableException;
 
 public class TruststoreFileFactoryException extends ExitableException {
-    public TruststoreFileFactoryException(String message) {
-        super(message, ExitStatus.TRUSTSTORE_FILE_FACTORY_EXCEPTION);
+    public TruststoreFileFactoryException(String errorMessage) {
+        super(errorMessage, ExitStatus.TRUSTSTORE_FILE_FACTORY_EXCEPTION);
     }
 
 }
diff --git a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/exception/WriteTruststoreFileException.java b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/merger/exception/WriteTruststoreFileException.java
index a5e02b3c..fe368868 100644
--- a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/exception/WriteTruststoreFileException.java
+++ b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/merger/exception/WriteTruststoreFileException.java
@@ -18,14 +18,14 @@
  */
 
 
-package org.onap.oom.truststoremerger.certification.file.exception;
+package org.onap.oom.truststoremerger.merger.exception;
 
 import org.onap.oom.truststoremerger.api.ExitStatus;
 import org.onap.oom.truststoremerger.api.ExitableException;
 
 public class WriteTruststoreFileException extends ExitableException {
 
-    public WriteTruststoreFileException(Exception e) {
-        super(e, ExitStatus.WRITE_TRUSTSTORE_FILE_EXCEPTION);
+    public WriteTruststoreFileException(Exception cause) {
+        super(cause, ExitStatus.WRITE_TRUSTSTORE_FILE_EXCEPTION);
     }
 }
diff --git a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/provider/JavaCertificateStoreController.java b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/merger/model/JavaTruststore.java
index a4b129c9..e3a03996 100644
--- a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/provider/JavaCertificateStoreController.java
+++ b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/merger/model/JavaTruststore.java
@@ -17,7 +17,7 @@
  * ============LICENSE_END=========================================================
  */
 
-package org.onap.oom.truststoremerger.certification.file.provider;
+package org.onap.oom.truststoremerger.merger.model;
 
 import java.io.File;
 import java.io.FileInputStream;
@@ -28,33 +28,40 @@ import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
 import org.onap.oom.truststoremerger.api.ExitableException;
-import org.onap.oom.truststoremerger.certification.file.exception.AliasConflictException;
-import org.onap.oom.truststoremerger.certification.file.exception.LoadTruststoreException;
-import org.onap.oom.truststoremerger.certification.file.exception.MissingTruststoreException;
-import org.onap.oom.truststoremerger.certification.file.exception.TruststoreDataOperationException;
-import org.onap.oom.truststoremerger.certification.file.exception.WriteTruststoreFileException;
-import org.onap.oom.truststoremerger.certification.file.provider.entry.CertificateWithAlias;
-import org.onap.oom.truststoremerger.certification.file.provider.entry.CertificateWithAliasFactory;
+import org.onap.oom.truststoremerger.merger.exception.AliasConflictException;
+import org.onap.oom.truststoremerger.merger.exception.LoadTruststoreException;
+import org.onap.oom.truststoremerger.merger.exception.MissingTruststoreException;
+import org.onap.oom.truststoremerger.merger.exception.TruststoreDataOperationException;
+import org.onap.oom.truststoremerger.merger.exception.WriteTruststoreFileException;
+import org.onap.oom.truststoremerger.merger.model.certificate.CertificateWithAlias;
+import org.onap.oom.truststoremerger.merger.model.certificate.CertificateWithAliasFactory;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-public class JavaCertificateStoreController implements CertificateController {
+public final class JavaTruststore extends Truststore {
 
-    private static final Logger LOGGER = LoggerFactory.getLogger(JavaCertificateStoreController.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(JavaTruststore.class);
 
     private final CertificateWithAliasFactory factory = new CertificateWithAliasFactory();
     private final KeyStore keyStore;
-    private final File storeFile;
     private final String password;
 
 
-    public JavaCertificateStoreController(KeyStore keyStore, File storeFile, String password) {
+    private JavaTruststore(KeyStore keyStore, File storeFile, String password) {
+        super(storeFile);
         this.keyStore = keyStore;
-        this.storeFile = storeFile;
         this.password = password;
     }
 
-    public List<CertificateWithAlias> getNotEmptyCertificateList() throws ExitableException {
+    public static JavaTruststore createWithLoadingFile(KeyStore keyStore, File storeFile, String password)
+        throws LoadTruststoreException {
+        JavaTruststore javaTruststore = new JavaTruststore(keyStore, storeFile, password);
+        javaTruststore.loadFile();
+        return javaTruststore;
+    }
+
+    public List<CertificateWithAlias> getCertificates() throws ExitableException {
+        LOGGER.debug("Attempt to read certificates from file: {}", storeFile.getPath());
         List<String> aliases = getTruststoreAliases();
         if (aliases.isEmpty()) {
             throw new MissingTruststoreException("Missing certificate aliases in file: " + storeFile.getPath());
@@ -64,6 +71,7 @@ public class JavaCertificateStoreController implements CertificateController {
 
     public void addCertificates(List<CertificateWithAlias> certificatesWithAliases)
         throws ExitableException {
+        LOGGER.debug("Attempt to add certificates for saving to file");
         if (getTruststoreAliases().isEmpty()) {
             throw new MissingTruststoreException("Missing certificate aliases in file: " + storeFile.getPath());
         }
@@ -73,7 +81,8 @@ public class JavaCertificateStoreController implements CertificateController {
     }
 
     public void saveFile() throws WriteTruststoreFileException {
-        try (FileOutputStream outputStream = new FileOutputStream(this.storeFile)) {
+        LOGGER.debug("Attempt to save file: {}", storeFile.getPath());
+        try (FileOutputStream outputStream = new FileOutputStream(storeFile)) {
             keyStore.store(outputStream, this.password.toCharArray());
         } catch (Exception e) {
             LOGGER.error("Cannot write truststore file");
@@ -81,11 +90,11 @@ public class JavaCertificateStoreController implements CertificateController {
         }
     }
 
-    public void loadFile() throws LoadTruststoreException {
+    private void loadFile() throws LoadTruststoreException {
         try {
-            keyStore.load(new FileInputStream(this.storeFile), this.password.toCharArray());
+            keyStore.load(new FileInputStream(storeFile), this.password.toCharArray());
         } catch (Exception e) {
-            LOGGER.error("Cannot load file: {}", this.storeFile.getPath());
+            LOGGER.error("Cannot load file: {}", storeFile.getPath());
             throw new LoadTruststoreException(e);
         }
     }
diff --git a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/merger/model/JavaTruststoreFactory.java b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/merger/model/JavaTruststoreFactory.java
new file mode 100644
index 00000000..d40cfb1a
--- /dev/null
+++ b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/merger/model/JavaTruststoreFactory.java
@@ -0,0 +1,51 @@
+/*============LICENSE_START=======================================================
+ * oom-truststore-merger
+ * ================================================================================
+ * Copyright (C) 2020 Nokia. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.oom.truststoremerger.merger.model;
+
+import java.io.File;
+import java.security.KeyStore;
+import java.security.KeyStoreException;
+import org.onap.oom.truststoremerger.common.PasswordReader;
+import org.onap.oom.truststoremerger.merger.exception.KeystoreInstanceException;
+import org.onap.oom.truststoremerger.merger.exception.LoadTruststoreException;
+import org.onap.oom.truststoremerger.merger.exception.PasswordReaderException;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class JavaTruststoreFactory {
+
+    private static final Logger LOGGER = LoggerFactory.getLogger(JavaTruststoreFactory.class);
+
+    private JavaTruststoreFactory() {
+    }
+
+    public static Truststore create(File certFile, String truststorePasswordPath, String keystoreType)
+        throws LoadTruststoreException, KeystoreInstanceException, PasswordReaderException {
+        String password = PasswordReader.readPassword(new File(truststorePasswordPath));
+        try {
+            return JavaTruststore
+                .createWithLoadingFile(KeyStore.getInstance(keystoreType), certFile, password);
+        } catch (KeyStoreException e) {
+            LOGGER.error("Cannot initialize Java Keystore instance");
+            throw new KeystoreInstanceException(e);
+        }
+    }
+}
+
diff --git a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/provider/PemCertificateController.java b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/merger/model/PemTruststore.java
index 9ff42b87..d04a01b1 100644
--- a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/provider/PemCertificateController.java
+++ b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/merger/model/PemTruststore.java
@@ -17,7 +17,7 @@
  * ============LICENSE_END=========================================================
  */
 
-package org.onap.oom.truststoremerger.certification.file.provider;
+package org.onap.oom.truststoremerger.merger.model;
 
 import static org.onap.oom.truststoremerger.api.CertificateConstants.BOUNCY_CASTLE_PROVIDER;
 import static org.onap.oom.truststoremerger.api.CertificateConstants.X_509_CERTIFICATE;
@@ -37,30 +37,30 @@ import org.bouncycastle.jce.provider.BouncyCastleProvider;
 import org.bouncycastle.openssl.jcajce.JcaMiscPEMGenerator;
 import org.bouncycastle.util.io.pem.PemObjectGenerator;
 import org.bouncycastle.util.io.pem.PemWriter;
-import org.onap.oom.truststoremerger.certification.file.provider.entry.CertificateWithAlias;
-import org.onap.oom.truststoremerger.certification.file.provider.entry.CertificateWithAliasFactory;
-import org.onap.oom.truststoremerger.certification.file.exception.MissingTruststoreException;
-import org.onap.oom.truststoremerger.certification.file.exception.TruststoreDataOperationException;
-import org.onap.oom.truststoremerger.certification.file.exception.WriteTruststoreFileException;
+import org.onap.oom.truststoremerger.merger.exception.MissingTruststoreException;
+import org.onap.oom.truststoremerger.merger.exception.TruststoreDataOperationException;
+import org.onap.oom.truststoremerger.merger.exception.WriteTruststoreFileException;
+import org.onap.oom.truststoremerger.merger.model.certificate.CertificateWithAlias;
+import org.onap.oom.truststoremerger.merger.model.certificate.CertificateWithAliasFactory;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-public class PemCertificateController implements CertificateController {
+public class PemTruststore extends Truststore {
 
-    private static final Logger LOGGER = LoggerFactory.getLogger(PemCertificateController.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(PemTruststore.class);
 
     private static final boolean APPEND_TO_FILE = true;
 
     private final CertificateWithAliasFactory factory = new CertificateWithAliasFactory();
     private final List<CertificateWithAlias> certificatesToBeSaved = new ArrayList<>();
-    private final File file;
 
-    public PemCertificateController(File file) {
-        this.file = file;
+    public PemTruststore(File storeFile) {
+        super(storeFile);
     }
 
-    public List<CertificateWithAlias> getNotEmptyCertificateList()
+    public List<CertificateWithAlias> getCertificates()
         throws TruststoreDataOperationException, MissingTruststoreException {
+        LOGGER.debug("Attempt to read certificates from file: {}", storeFile.getPath());
         if (isFileWithoutPemCertificate()) {
             throw new MissingTruststoreException("File does not contain any certificate");
         }
@@ -70,14 +70,16 @@ public class PemCertificateController implements CertificateController {
 
     public void addCertificates(List<CertificateWithAlias> certificates)
         throws TruststoreDataOperationException, MissingTruststoreException {
+        LOGGER.debug("Attempt to add certificates for saving to file");
         if (isFileWithoutPemCertificate()) {
-            LOGGER.error("File does not contain any certificate. File path: {} ", this.file.getPath());
+            LOGGER.error("File does not contain any certificate. File path: {} ", storeFile.getPath());
             throw new MissingTruststoreException("File does not contain any certificate");
         }
         certificatesToBeSaved.addAll(certificates);
     }
 
     public void saveFile() throws WriteTruststoreFileException, TruststoreDataOperationException {
+        LOGGER.debug("Attempt to save file: {}", storeFile.getPath());
         List<Certificate> certificates = certificatesToBeSaved.stream()
             .map(CertificateWithAlias::getCertificate)
             .collect(Collectors.toList());
@@ -104,19 +106,17 @@ public class PemCertificateController implements CertificateController {
         return sw.toString();
     }
 
-
     private List<Certificate> extractCertificatesFromFile() throws TruststoreDataOperationException {
-        try (FileInputStream inputStream = new FileInputStream(this.file)) {
+        try (FileInputStream inputStream = new FileInputStream(storeFile)) {
             Security.addProvider(new BouncyCastleProvider());
             CertificateFactory factory = CertificateFactory.getInstance(X_509_CERTIFICATE, BOUNCY_CASTLE_PROVIDER);
             return new ArrayList<>(factory.generateCertificates(inputStream));
         } catch (Exception e) {
-            LOGGER.error("Cannot read certificates from file: {}", this.file.getPath());
+            LOGGER.error("Cannot read certificates from file: {}", storeFile.getPath());
             throw new TruststoreDataOperationException(e);
         }
     }
 
-
     private List<PemObjectGenerator> transformToPemGenerators(List<Certificate> certificates)
         throws TruststoreDataOperationException {
         List<PemObjectGenerator> generators = new ArrayList<>();
@@ -145,7 +145,7 @@ public class PemCertificateController implements CertificateController {
 
     private void appendToFile(String certificatesAsString) throws WriteTruststoreFileException {
         try {
-            FileOutputStream fileOutputStream = new FileOutputStream(this.file, APPEND_TO_FILE);
+            FileOutputStream fileOutputStream = new FileOutputStream(storeFile, APPEND_TO_FILE);
             fileOutputStream.write(certificatesAsString.getBytes());
         } catch (Exception e) {
             LOGGER.error("Cannot write certificates to file");
diff --git a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/provider/CertificateController.java b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/merger/model/Truststore.java
index f2ed2c45..2c3acf49 100644
--- a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/provider/CertificateController.java
+++ b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/merger/model/Truststore.java
@@ -17,17 +17,30 @@
  * ============LICENSE_END=========================================================
  */
 
-package org.onap.oom.truststoremerger.certification.file.provider;
+package org.onap.oom.truststoremerger.merger.model;
 
+import java.io.File;
 import java.util.List;
 import org.onap.oom.truststoremerger.api.ExitableException;
-import org.onap.oom.truststoremerger.certification.file.provider.entry.CertificateWithAlias;
+import org.onap.oom.truststoremerger.merger.exception.CreateBackupException;
+import org.onap.oom.truststoremerger.merger.model.certificate.CertificateWithAlias;
+import org.onap.oom.truststoremerger.common.BackupCreator;
 
-public interface CertificateController {
+public abstract class Truststore {
 
-    List<CertificateWithAlias> getNotEmptyCertificateList() throws ExitableException;
+    final File storeFile;
 
-    void addCertificates(List<CertificateWithAlias> certificates) throws ExitableException;
+    public Truststore(File storeFile) {
+        this.storeFile = storeFile;
+    }
 
-    void saveFile() throws ExitableException;
+    public void createBackup() throws CreateBackupException {
+        BackupCreator.createBackup(storeFile);
+    }
+
+    public abstract List<CertificateWithAlias> getCertificates() throws ExitableException;
+
+    public abstract void addCertificates(List<CertificateWithAlias> certificates) throws ExitableException;
+
+    public abstract void saveFile() throws ExitableException;
 }
diff --git a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/merger/model/TruststoreFactory.java b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/merger/model/TruststoreFactory.java
new file mode 100644
index 00000000..7e4b71e3
--- /dev/null
+++ b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/merger/model/TruststoreFactory.java
@@ -0,0 +1,69 @@
+/*============LICENSE_START=======================================================
+ * oom-truststore-merger
+ * ================================================================================
+ * Copyright (C) 2020 Nokia. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.oom.truststoremerger.merger.model;
+
+import static org.onap.oom.truststoremerger.api.CertificateConstants.JKS_TYPE;
+import static org.onap.oom.truststoremerger.api.CertificateConstants.PKCS12_TYPE;
+
+import java.io.File;
+import org.onap.oom.truststoremerger.common.ExtensionResolver;
+import org.onap.oom.truststoremerger.merger.exception.KeystoreInstanceException;
+import org.onap.oom.truststoremerger.merger.exception.LoadTruststoreException;
+import org.onap.oom.truststoremerger.merger.exception.PasswordReaderException;
+import org.onap.oom.truststoremerger.merger.exception.TruststoreFileFactoryException;
+
+public class TruststoreFactory {
+
+    private static final String JKS_EXTENSION = ".jks";
+    private static final String P12_EXTENSION = ".p12";
+    private static final String PEM_EXTENSION = ".pem";
+    private static final String FILE_DOES_NOT_EXIST_MSG_TEMPLATE = "File: %s does not exist";
+    private static final String UNKNOWN_TRUSTSTORE_TYPE_MSG_TEMPLATE = "Unknown truststore extension type: %s";
+
+
+    private TruststoreFactory() {
+    }
+
+    public static Truststore create(String truststoreFilePath, String truststorePasswordPath)
+        throws TruststoreFileFactoryException, PasswordReaderException, KeystoreInstanceException, LoadTruststoreException {
+        File truststoreFile = new File(truststoreFilePath);
+        if (!ExtensionResolver.checkIfFileExists(truststoreFile)) {
+            throw new TruststoreFileFactoryException(String.format(FILE_DOES_NOT_EXIST_MSG_TEMPLATE, truststoreFile));
+        }
+        return createTypedTruststore(truststoreFile, truststorePasswordPath);
+    }
+
+    private static Truststore createTypedTruststore(File truststoreFile, String truststorePasswordPath)
+        throws KeystoreInstanceException, PasswordReaderException, LoadTruststoreException, TruststoreFileFactoryException {
+        String extension = ExtensionResolver.get(truststoreFile);
+        switch (extension) {
+            case JKS_EXTENSION:
+                return JavaTruststoreFactory.create(truststoreFile, truststorePasswordPath, JKS_TYPE);
+            case P12_EXTENSION:
+                return JavaTruststoreFactory.create(truststoreFile, truststorePasswordPath, PKCS12_TYPE);
+            case PEM_EXTENSION:
+                return new PemTruststore(truststoreFile);
+            default:
+                throw new TruststoreFileFactoryException(
+                    String.format(UNKNOWN_TRUSTSTORE_TYPE_MSG_TEMPLATE, extension));
+        }
+    }
+
+}
diff --git a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/provider/entry/CertificateWithAlias.java b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/merger/model/certificate/CertificateWithAlias.java
index decc3977..990a1c66 100644
--- a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/provider/entry/CertificateWithAlias.java
+++ b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/merger/model/certificate/CertificateWithAlias.java
@@ -17,7 +17,7 @@
  * ============LICENSE_END=========================================================
  */
 
-package org.onap.oom.truststoremerger.certification.file.provider.entry;
+package org.onap.oom.truststoremerger.merger.model.certificate;
 
 import java.security.cert.Certificate;
 
diff --git a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/provider/entry/CertificateWithAliasFactory.java b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/merger/model/certificate/CertificateWithAliasFactory.java
index 0889650e..ce3c0c47 100644
--- a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/provider/entry/CertificateWithAliasFactory.java
+++ b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/merger/model/certificate/CertificateWithAliasFactory.java
@@ -17,7 +17,7 @@
  * ============LICENSE_END=========================================================
  */
 
-package org.onap.oom.truststoremerger.certification.file.provider.entry;
+package org.onap.oom.truststoremerger.merger.model.certificate;
 
 import java.security.cert.Certificate;
 
diff --git a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/provider/entry/PemAliasGenerator.java b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/merger/model/certificate/PemAliasGenerator.java
index 56faa1f6..b812fcb3 100644
--- a/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/certification/file/provider/entry/PemAliasGenerator.java
+++ b/trustStoreMerger/src/main/java/org/onap/oom/truststoremerger/merger/model/certificate/PemAliasGenerator.java
@@ -17,7 +17,7 @@
  * ============LICENSE_END=========================================================
  */
 
-package org.onap.oom.truststoremerger.certification.file.provider.entry;
+package org.onap.oom.truststoremerger.merger.model.certificate;
 
 
 import java.util.concurrent.atomic.AtomicInteger;