Abstract utility classes for re-use

When looking at the existing uses of BundleActivator(s), it became
immediately clear that other parts of the code have a strategy based
properties file resolution very similar to those abstracted by dblib.
This change aggregates a separate utils bundle for this functionality,
which is further abstracted for potential reuse with other use cases.

The next use case is in the sli bundle, which will be handled in
a follow-up patch.

Issue-Id: SDNC-54
Change-Id: Ie4d4bb679617474b1983e6044c08cca1742b9893
Signed-off-by: Ryan Goulding <ryandgoulding@gmail.com>

12 files changed, 479 insertions, 0 deletions

diff --git a/utils/pom.xml b/utils/pom.xml
new file mode 100644
index 00000000..93326a9d
--- /dev/null
+++ b/utils/pom.xml
@@ -0,0 +1,56 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+
+    <parent>
+        <groupId>org.onap.ccsdk.sli.core</groupId>
+        <artifactId>ccsdk-sli-core</artifactId>
+        <version>0.1.2-SNAPSHOT</version>
+    </parent>
+
+    <modelVersion>4.0.0</modelVersion>
+    <packaging>bundle</packaging>
+    <artifactId>utils</artifactId>
+    <name>SLI Core Utilities Package</name>
+
+    <description>
+        The SLI Core Utilities Package provides common functionality for setting up SLI connectivity.
+    </description>
+
+    <dependencies>
+        <dependency>
+            <groupId>com.google.guava</groupId>
+            <artifactId>guava</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>equinoxSDK381</groupId>
+            <artifactId>org.eclipse.osgi</artifactId>
+            <version>${equinox.osgi.version}</version>
+        </dependency>
+
+        <!-- Testing Dependencies -->
+        <dependency>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-core</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.felix</groupId>
+                <artifactId>maven-bundle-plugin</artifactId>
+                <version>${bundle.plugin.version}</version>
+            </plugin>
+        </plugins>
+    </build>
+    <organization>
+        <name>Inocybe Technologies and Others</name>
+    </organization>
+</project>
diff --git a/utils/src/main/java/org/onap/ccsdk/sli/core/utils/DefaultFileResolver.java b/utils/src/main/java/org/onap/ccsdk/sli/core/utils/DefaultFileResolver.java
new file mode 100644
index 00000000..8938aa6e
--- /dev/null
+++ b/utils/src/main/java/org/onap/ccsdk/sli/core/utils/DefaultFileResolver.java
@@ -0,0 +1,61 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * onap
+ * ================================================================================
+ * Copyright (C) 2016 - 2017 ONAP
+ * ================================================================================
+ * 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.ccsdk.sli.core.utils;
+
+import java.io.File;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.Optional;
+
+/**
+ * Resolves dblib properties files relative to the default file path.  In Unix, this is represented by:
+ * <code>/opt/sdnc/data/properties</code>
+ */
+public abstract class DefaultFileResolver implements PropertiesFileResolver {
+
+    private final String successMessage;
+
+    private final Path propertyPath;
+
+    public DefaultFileResolver(final String successMessage, final Path propertyPath) {
+        this.successMessage = successMessage;
+        this.propertyPath = propertyPath;
+    }
+
+    /**
+     * Parse a properties file location based on the default properties location
+     *
+     * @return an Optional File containing the location if it exists, or an empty Optional
+     */
+    @Override
+    public Optional<File> resolveFile(final String filename) {
+        final File fileFromDefaultDblibDir = propertyPath.resolve(filename).toFile();
+        if (fileFromDefaultDblibDir.exists()) {
+            return Optional.of(fileFromDefaultDblibDir);
+        }
+        return Optional.empty();
+    }
+
+    @Override
+    public String getSuccessfulResolutionMessage() {
+        return this.successMessage;
+    }
+}
diff --git a/utils/src/main/java/org/onap/ccsdk/sli/core/utils/EnvVarFileResolver.java b/utils/src/main/java/org/onap/ccsdk/sli/core/utils/EnvVarFileResolver.java
new file mode 100644
index 00000000..3e438d1a
--- /dev/null
+++ b/utils/src/main/java/org/onap/ccsdk/sli/core/utils/EnvVarFileResolver.java
@@ -0,0 +1,70 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * onap
+ * ================================================================================
+ * Copyright (C) 2016 - 2017 ONAP
+ * ================================================================================
+ * 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.ccsdk.sli.core.utils;
+
+import com.google.common.base.Strings;
+
+import java.io.File;
+import java.nio.file.Paths;
+import java.util.Optional;
+
+/**
+ * Resolves dblib properties files relative to the directory identified by the <code>SDNC_CONFIG_DIR</code>
+ * environment variable.
+ */
+public abstract class EnvVarFileResolver implements PropertiesFileResolver {
+
+    /**
+     * Key for environment variable representing the configuration directory
+     */
+    private final String propertyKey;
+
+    private final String successMessage;
+
+    public EnvVarFileResolver(final String successMessage, final String propertyKey) {
+        this.successMessage = successMessage;
+        this.propertyKey = propertyKey;
+    }
+
+    /**
+     * Parse a properties file location based on System environment variable
+     *
+     * @return an Optional File containing the location if it exists, or an empty Optional
+     */
+    @Override
+    public Optional<File> resolveFile(final String filename) {
+        // attempt to resolve the property directory from the corresponding environment variable
+        final String propDirectoryFromEnvVariable = System.getenv(propertyKey);
+        final File fileFromEnvVariable;
+        if (!Strings.isNullOrEmpty(propDirectoryFromEnvVariable)) {
+            fileFromEnvVariable = Paths.get(propDirectoryFromEnvVariable).resolve(filename).toFile();
+            if(fileFromEnvVariable.exists()) {
+                return Optional.of(fileFromEnvVariable);
+            }
+        }
+        return Optional.empty();
+    }
+
+    @Override
+    public String getSuccessfulResolutionMessage() {
+        return this.successMessage;
+    }
+}
diff --git a/utils/src/main/java/org/onap/ccsdk/sli/core/utils/JREFileResolver.java b/utils/src/main/java/org/onap/ccsdk/sli/core/utils/JREFileResolver.java
new file mode 100644
index 00000000..5cd6c360
--- /dev/null
+++ b/utils/src/main/java/org/onap/ccsdk/sli/core/utils/JREFileResolver.java
@@ -0,0 +1,74 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * onap
+ * ================================================================================
+ * Copyright (C) 2016 - 2017 ONAP
+ * ================================================================================
+ * 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.ccsdk.sli.core.utils;
+
+import java.io.File;
+import java.net.URISyntaxException;
+import java.net.URL;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.Optional;
+import org.osgi.framework.FrameworkUtil;
+
+/**
+ * Resolves dblib properties files relative to the directory identified by the JRE property
+ * <code>dblib.properties</code>.
+ */
+public class JREFileResolver implements PropertiesFileResolver {
+
+    /**
+     * Key for JRE argument representing the configuration directory
+     */
+    private static final String DBLIB_JRE_PROPERTY_KEY = "dblib.properties";
+
+    private final String successMessage;
+    private final Class clazz;
+
+    public JREFileResolver(final String successMessage, final Class clazz) {
+        this.successMessage = successMessage;
+        this.clazz = clazz;
+    }
+
+    /**
+     * Parse a properties file location based on JRE argument
+     *
+     * @return an Optional File containing the location if it exists, or an empty Optional
+     */
+    @Override
+    public Optional<File> resolveFile(final String filename) {
+        final URL jreArgumentUrl = FrameworkUtil.getBundle(this.clazz)
+                .getResource(DBLIB_JRE_PROPERTY_KEY);
+        try {
+            if (jreArgumentUrl == null) {
+                return Optional.empty();
+            }
+            final Path dblibPath = Paths.get(jreArgumentUrl.toURI());
+            return Optional.of(dblibPath.resolve(filename).toFile());
+        } catch(final URISyntaxException e) {
+            return Optional.empty();
+        }
+    }
+
+    @Override
+    public String getSuccessfulResolutionMessage() {
+        return this.successMessage;
+    }
+}
diff --git a/utils/src/main/java/org/onap/ccsdk/sli/core/utils/KarafRootFileResolver.java b/utils/src/main/java/org/onap/ccsdk/sli/core/utils/KarafRootFileResolver.java
new file mode 100644
index 00000000..0cb75450
--- /dev/null
+++ b/utils/src/main/java/org/onap/ccsdk/sli/core/utils/KarafRootFileResolver.java
@@ -0,0 +1,63 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * onap
+ * ================================================================================
+ * Copyright (C) 2016 - 2017 ONAP
+ * ================================================================================
+ * 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.ccsdk.sli.core.utils;
+
+import java.io.File;
+import java.net.URL;
+import java.util.Optional;
+
+/**
+ * Resolves dblib properties files relative to the karaf root directory.
+ */
+public class KarafRootFileResolver implements PropertiesFileResolver {
+
+    final Object provider;
+
+    private final String successMessage;
+
+    public KarafRootFileResolver(final String successMessage, final Object provider) {
+        this.successMessage = successMessage;
+        this.provider = provider;
+    }
+
+    /**
+     * Parse a properties file location relative to the karaf root
+     *
+     * @return an Optional File containing the location if it exists, or an empty Optional
+     */
+    @Override
+    public Optional<File> resolveFile(final String filename) {
+        final URL fromKarafRoot = provider.getClass().getResource(filename);
+        if (fromKarafRoot != null) {
+            final File propertiesFile = new File(fromKarafRoot.getFile());
+            if (propertiesFile.exists()) {
+                return Optional.of(propertiesFile);
+            }
+            return Optional.empty();
+        }
+        return Optional.empty();
+    }
+
+    @Override
+    public String getSuccessfulResolutionMessage() {
+        return this.successMessage;
+    }
+}
diff --git a/utils/src/main/java/org/onap/ccsdk/sli/core/utils/PropertiesFileResolver.java b/utils/src/main/java/org/onap/ccsdk/sli/core/utils/PropertiesFileResolver.java
new file mode 100644
index 00000000..bfb417dc
--- /dev/null
+++ b/utils/src/main/java/org/onap/ccsdk/sli/core/utils/PropertiesFileResolver.java
@@ -0,0 +1,45 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * onap
+ * ================================================================================
+ * Copyright (C) 2016 - 2017 ONAP
+ * ================================================================================
+ * 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.ccsdk.sli.core.utils;
+
+import java.io.File;
+import java.util.Optional;
+
+/**
+ * Strategy for resolving dblib properties.
+ */
+public interface PropertiesFileResolver {
+
+    /**
+     * Resolve dblib properties file.
+     *
+     * @param filename the name of the file to look for at the specific location.
+     * @return An optional File or empty.
+     */
+    Optional<File> resolveFile(final String filename);
+
+    /**
+     * A success message, used only for logging now.
+     *
+     * @return a success message, used only for logging now.
+     */
+    String getSuccessfulResolutionMessage();
+}
diff --git a/utils/src/main/java/org/onap/ccsdk/sli/core/utils/dblib/DblibDefaultFileResolver.java b/utils/src/main/java/org/onap/ccsdk/sli/core/utils/dblib/DblibDefaultFileResolver.java
new file mode 100644
index 00000000..56b4ca1b
--- /dev/null
+++ b/utils/src/main/java/org/onap/ccsdk/sli/core/utils/dblib/DblibDefaultFileResolver.java
@@ -0,0 +1,17 @@
+package org.onap.ccsdk.sli.core.utils.dblib;
+
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import org.onap.ccsdk.sli.core.utils.DefaultFileResolver;
+
+public class DblibDefaultFileResolver extends DefaultFileResolver {
+
+    /**
+     * Default path to look for the configuration directory
+     */
+    private static final Path DEFAULT_DBLIB_PROP_DIR = Paths.get("opt", "sdnc", "data", "properties");
+
+    public DblibDefaultFileResolver(final String successMessage) {
+        super(successMessage, DEFAULT_DBLIB_PROP_DIR);
+    }
+}
diff --git a/utils/src/main/java/org/onap/ccsdk/sli/core/utils/dblib/DblibEnvVarFileResolver.java b/utils/src/main/java/org/onap/ccsdk/sli/core/utils/dblib/DblibEnvVarFileResolver.java
new file mode 100644
index 00000000..9eef4cee
--- /dev/null
+++ b/utils/src/main/java/org/onap/ccsdk/sli/core/utils/dblib/DblibEnvVarFileResolver.java
@@ -0,0 +1,15 @@
+package org.onap.ccsdk.sli.core.utils.dblib;
+
+import org.onap.ccsdk.sli.core.utils.EnvVarFileResolver;
+
+public class DblibEnvVarFileResolver extends EnvVarFileResolver {
+
+    /**
+     * Key for environment variable representing the configuration directory
+     */
+    private static final String SDNC_CONFIG_DIR_PROP_KEY = "SDNC_CONFIG_DIR";
+
+    public DblibEnvVarFileResolver(final String successMessage) {
+        super(successMessage, SDNC_CONFIG_DIR_PROP_KEY);
+    }
+}
diff --git a/utils/src/test/java/org/onap/ccsdk/sli/core/utils/JREFileResolverTest.java b/utils/src/test/java/org/onap/ccsdk/sli/core/utils/JREFileResolverTest.java
new file mode 100644
index 00000000..e5051d65
--- /dev/null
+++ b/utils/src/test/java/org/onap/ccsdk/sli/core/utils/JREFileResolverTest.java
@@ -0,0 +1,15 @@
+package org.onap.ccsdk.sli.core.utils;
+
+import static org.junit.Assert.*;
+
+import org.junit.Test;
+
+public class JREFileResolverTest {
+
+    @Test
+    public void getSuccessfulResolutionMessage() throws Exception {
+        final PropertiesFileResolver resolver = new JREFileResolver("success", JREFileResolverTest.class);
+        assertEquals("success", resolver.getSuccessfulResolutionMessage());
+    }
+
+}
\ No newline at end of file
diff --git a/utils/src/test/java/org/onap/ccsdk/sli/core/utils/KarafRootFileResolverTest.java b/utils/src/test/java/org/onap/ccsdk/sli/core/utils/KarafRootFileResolverTest.java
new file mode 100644
index 00000000..5e407daf
--- /dev/null
+++ b/utils/src/test/java/org/onap/ccsdk/sli/core/utils/KarafRootFileResolverTest.java
@@ -0,0 +1,14 @@
+package org.onap.ccsdk.sli.core.utils;
+
+import static org.junit.Assert.*;
+
+import org.junit.Test;
+
+public class KarafRootFileResolverTest {
+    @Test
+    public void getSuccessfulResolutionMessage() throws Exception {
+        final PropertiesFileResolver resolver = new KarafRootFileResolver("success", null);
+        assertEquals("success", resolver.getSuccessfulResolutionMessage());
+    }
+
+}
\ No newline at end of file
diff --git a/utils/src/test/java/org/onap/ccsdk/sli/core/utils/dblib/DblibDefaultFileResolverTest.java b/utils/src/test/java/org/onap/ccsdk/sli/core/utils/dblib/DblibDefaultFileResolverTest.java
new file mode 100644
index 00000000..4b28d449
--- /dev/null
+++ b/utils/src/test/java/org/onap/ccsdk/sli/core/utils/dblib/DblibDefaultFileResolverTest.java
@@ -0,0 +1,25 @@
+package org.onap.ccsdk.sli.core.utils.dblib;
+
+import static org.junit.Assert.*;
+
+import java.io.File;
+import java.util.Optional;
+import org.junit.Test;
+import org.onap.ccsdk.sli.core.utils.PropertiesFileResolver;
+
+public class DblibDefaultFileResolverTest {
+
+    @Test
+    public void resolveFile() throws Exception {
+        final PropertiesFileResolver resolver = new DblibDefaultFileResolver("success");
+        final Optional<File> file = resolver.resolveFile("doesnotexist.cfg");
+        assertFalse(file.isPresent());
+    }
+
+    @Test
+    public void getSuccessfulResolutionMessage() throws Exception {
+        final PropertiesFileResolver resolver = new DblibDefaultFileResolver("success");
+        assertEquals("success", resolver.getSuccessfulResolutionMessage());
+    }
+
+}
\ No newline at end of file
diff --git a/utils/src/test/java/org/onap/ccsdk/sli/core/utils/dblib/DblibEnvVarFileResolverTest.java b/utils/src/test/java/org/onap/ccsdk/sli/core/utils/dblib/DblibEnvVarFileResolverTest.java
new file mode 100644
index 00000000..bae4168d
--- /dev/null
+++ b/utils/src/test/java/org/onap/ccsdk/sli/core/utils/dblib/DblibEnvVarFileResolverTest.java
@@ -0,0 +1,24 @@
+package org.onap.ccsdk.sli.core.utils.dblib;
+
+import static org.junit.Assert.*;
+
+import java.io.File;
+import java.util.Optional;
+import org.junit.Test;
+import org.onap.ccsdk.sli.core.utils.PropertiesFileResolver;
+
+public class DblibEnvVarFileResolverTest {
+    @Test
+    public void resolveFile() throws Exception {
+        final PropertiesFileResolver resolver = new DblibEnvVarFileResolver("success");
+        final Optional<File> file = resolver.resolveFile("doesnotexist.cfg");
+        assertFalse(file.isPresent());
+    }
+
+    @Test
+    public void getSuccessfulResolutionMessage() throws Exception {
+        final PropertiesFileResolver resolver = new DblibEnvVarFileResolver("success");
+        assertEquals("success", resolver.getSuccessfulResolutionMessage());
+    }
+
+}
\ No newline at end of file