Increase sonar coverage for common

Add Junit test in appc-common
 - cache
   - cache/impl
 - configuration
 - exceptions
 - i18n
 - logging

Issue-Id: APPC-230
Change-Id: I04c457da4dfa881c1109273b8fd3e16e76ebd68f
Signed-off-by: beili.zhou <beili.zhou@amdocs.com>

13 files changed, 204 insertions, 79 deletions

diff --git a/appc-common/src/main/java/org/openecomp/appc/Constants.java b/appc-common/src/main/java/org/openecomp/appc/Constants.java
index c5315edd7..5e59971ac 100644
--- a/appc-common/src/main/java/org/openecomp/appc/Constants.java
+++ b/appc-common/src/main/java/org/openecomp/appc/Constants.java
@@ -168,10 +168,10 @@ public final class Constants {
     @SuppressWarnings("nls")
     public static final String STATUS_GETTER = "status-getter";
 
-	@SuppressWarnings("nls")
+    @SuppressWarnings("nls")
     public static final String VM_FUSION_STATUS_GETTER = "fusion-vm-status-getter";
 
-	/**
+    /**
      * The name for the status vm attribute to be set in the context when executing a vmstatuscheck.
      */
 
diff --git a/appc-common/src/main/java/org/openecomp/appc/cache/CacheStrategies.java b/appc-common/src/main/java/org/openecomp/appc/cache/CacheStrategies.java
index 7f63e00bf..196b645a9 100644
--- a/appc-common/src/main/java/org/openecomp/appc/cache/CacheStrategies.java
+++ b/appc-common/src/main/java/org/openecomp/appc/cache/CacheStrategies.java
@@ -24,7 +24,9 @@
 
 package org.openecomp.appc.cache;
 
-
+/**
+ * Enum of CacheStrategies
+ */
 public enum CacheStrategies {
-    LRU;
+    LRU
 }
diff --git a/appc-common/src/main/java/org/openecomp/appc/cache/CacheStrategy.java b/appc-common/src/main/java/org/openecomp/appc/cache/CacheStrategy.java
index aa0a5d785..e07708119 100644
--- a/appc-common/src/main/java/org/openecomp/appc/cache/CacheStrategy.java
+++ b/appc-common/src/main/java/org/openecomp/appc/cache/CacheStrategy.java
@@ -24,8 +24,23 @@
 
 package org.openecomp.appc.cache;
 
-
-public interface CacheStrategy <K,V>{
+/**
+ * Interface of CacheStrategy
+ * @param <K> key
+ * @param <V> value
+ */
+public interface CacheStrategy <K,V> {
+    /**
+     * Get object
+     * @param key of the object
+     * @return value of the object
+     */
     V getObject(K key);
+
+    /**
+     * Put object
+     * @param key of the object
+     * @param value of the object
+     */
     void putObject(K key,V value);
 }
diff --git a/appc-common/src/main/java/org/openecomp/appc/cache/MetadataCache.java b/appc-common/src/main/java/org/openecomp/appc/cache/MetadataCache.java
index d5b1d7b93..8196e8e3d 100644
--- a/appc-common/src/main/java/org/openecomp/appc/cache/MetadataCache.java
+++ b/appc-common/src/main/java/org/openecomp/appc/cache/MetadataCache.java
@@ -24,8 +24,23 @@
 
 package org.openecomp.appc.cache;
 
-
-public interface MetadataCache <K,V>{
+/**
+ * Interface of MetadataCache
+ * @param <K> key
+ * @param <V> value
+ */
+public interface MetadataCache <K,V> {
+    /**
+     * Get object
+     * @param key of the object
+     * @return value of the object
+     */
     V getObject(K key);
+
+    /**
+     * Put object
+     * @param key of the object
+     * @param value of the object
+     */
     void putObject(K key,V value);
 }
diff --git a/appc-common/src/main/java/org/openecomp/appc/cache/impl/LRUCache.java b/appc-common/src/main/java/org/openecomp/appc/cache/impl/LRUCache.java
index 5cb8ef534..b97a5f642 100644
--- a/appc-common/src/main/java/org/openecomp/appc/cache/impl/LRUCache.java
+++ b/appc-common/src/main/java/org/openecomp/appc/cache/impl/LRUCache.java
@@ -29,12 +29,17 @@ import java.util.Map;
 
 import org.openecomp.appc.cache.CacheStrategy;
 
+/**
+ * LRU cache implements CacheStategy<K, V>
+ * @param <K> Key
+ * @param <V> Value
+ */
 public class LRUCache<K,V> implements CacheStrategy<K,V> {
 
     private Map<K,V> map;
 
     LRUCache(final Integer capacity){
-        map = new LinkedHashMap<K,V>(capacity, 0.75F, true){
+        map = new LinkedHashMap<K,V>(capacity, 0.75F, true) {
             @Override
             protected boolean removeEldestEntry(Map.Entry<K, V> eldest){
                 return size() > capacity;
diff --git a/appc-common/src/main/java/org/openecomp/appc/cache/impl/MetadataCacheFactory.java b/appc-common/src/main/java/org/openecomp/appc/cache/impl/MetadataCacheFactory.java
index 306a23a99..91ad48f9b 100644
--- a/appc-common/src/main/java/org/openecomp/appc/cache/impl/MetadataCacheFactory.java
+++ b/appc-common/src/main/java/org/openecomp/appc/cache/impl/MetadataCacheFactory.java
@@ -25,16 +25,23 @@
 package org.openecomp.appc.cache.impl;
 
 import org.openecomp.appc.cache.CacheStrategies;
-import org.openecomp.appc.cache.CacheStrategy;
 import org.openecomp.appc.cache.MetadataCache;
 
+/**
+ * Metadata Cache Factory
+ */
 public class MetadataCacheFactory {
 
-    private static class ReferenceHolder{
+    private static class ReferenceHolder {
+        private ReferenceHolder() {
+            throw new IllegalAccessError("ReferenceHolder");
+        }
+
         private static final MetadataCacheFactory FACTORY = new MetadataCacheFactory();
     }
-    private MetadataCacheFactory(){
 
+    private MetadataCacheFactory() {
+        // do nothing
     }
 
     public static MetadataCacheFactory getInstance(){
@@ -44,7 +51,13 @@ public class MetadataCacheFactory {
     public MetadataCache getMetadataCache(){
         return new MetadataCacheImpl();
     }
-    public MetadataCache getMetadataCache(CacheStrategies cacheStrategy){
+
+    /**
+     * Get MetadataCache
+     * @param cacheStrategy the CacheStrategies to be used to build MetadataCacheImpl
+     * @return a new instance of MetadataCacheImpl
+     */
+    public MetadataCache getMetadataCache(CacheStrategies cacheStrategy) {
         return new MetadataCacheImpl(cacheStrategy);
     }
 
diff --git a/appc-common/src/main/java/org/openecomp/appc/cache/impl/MetadataCacheImpl.java b/appc-common/src/main/java/org/openecomp/appc/cache/impl/MetadataCacheImpl.java
index 966100666..249a97c3c 100644
--- a/appc-common/src/main/java/org/openecomp/appc/cache/impl/MetadataCacheImpl.java
+++ b/appc-common/src/main/java/org/openecomp/appc/cache/impl/MetadataCacheImpl.java
@@ -28,7 +28,11 @@ import org.openecomp.appc.cache.CacheStrategies;
 import org.openecomp.appc.cache.CacheStrategy;
 import org.openecomp.appc.cache.MetadataCache;
 
-
+/**
+ * Implementation of MetadataCache
+ * @param <K> Key
+ * @param <V> Value
+ */
 public class MetadataCacheImpl<K,V> implements MetadataCache<K,V> {
 
     private CacheStrategy strategy;
@@ -42,9 +46,13 @@ public class MetadataCacheImpl<K,V> implements MetadataCache<K,V> {
     }
 
     private CacheStrategy initializeStrategy(CacheStrategies strategy) {
-        switch (strategy){
-            case LRU:
-                return new LRUCache<>(50);
+        if (strategy != null) {
+            switch (strategy) {
+                case LRU:
+                    return new LRUCache<>(50);
+                default:
+                    // do nothing
+            }
         }
         return null;
     }
diff --git a/appc-common/src/main/java/org/openecomp/appc/configuration/DefaultConfiguration.java b/appc-common/src/main/java/org/openecomp/appc/configuration/DefaultConfiguration.java
index 96d9be86c..635384952 100644
--- a/appc-common/src/main/java/org/openecomp/appc/configuration/DefaultConfiguration.java
+++ b/appc-common/src/main/java/org/openecomp/appc/configuration/DefaultConfiguration.java
@@ -24,7 +24,6 @@
 
 package org.openecomp.appc.configuration;
 
-
 import java.io.IOException;
 import java.io.InputStream;
 import java.net.URL;
@@ -64,7 +63,7 @@ public final class DefaultConfiguration implements Configuration, Cloneable {
     /**
      * Construct the configuration object.
      */
-    public DefaultConfiguration() {
+    DefaultConfiguration() {
         // do nothing
     }
 
@@ -97,22 +96,20 @@ public final class DefaultConfiguration implements Configuration, Cloneable {
      */
     @SuppressWarnings("nls")
     private static String decrypt(String value) {
-        if (value != null) {
-            if (value.startsWith(EncryptionTool.ENCRYPTED_VALUE_PREFIX)) {
-                try {
-                    return EncryptionTool.getInstance().decrypt(value);
-                } catch (Exception e) {
-                    StringBuilder out = new StringBuilder();
-                    for (Provider p : Security.getProviders()) {
-                        for (Service s : p.getServices()) {
-                            String algo = s.getAlgorithm();
-                            out.append(String.format("\n==Found Algorithm [ %s ] in provider [ %s ] and service [ %s ]",
-                                    algo, p.getName(), s.getClassName()));
-                        }
+        if (value != null && value.startsWith(EncryptionTool.ENCRYPTED_VALUE_PREFIX)) {
+            try {
+                return EncryptionTool.getInstance().decrypt(value);
+            } catch (Exception e) {
+                StringBuilder out = new StringBuilder();
+                for (Provider p : Security.getProviders()) {
+                    for (Service s : p.getServices()) {
+                        String algo = s.getAlgorithm();
+                        out.append(String.format("\n==Found Algorithm [ %s ] in provider [ %s ] and service [ %s ]",
+                                algo, p.getName(), s.getClassName()));
                     }
-                    logger.debug(out.toString());
-                    logger.warn(String.format("Could not decrypt the configuration value [%s]", value), e);
                 }
+                logger.debug(out.toString());
+                logger.warn(String.format("Could not decrypt the configuration value [%s]", value), e);
             }
         }
         return value;
@@ -172,9 +169,9 @@ public final class DefaultConfiguration implements Configuration, Cloneable {
         // template = decrypt(template); DH: Do not assign values to parameters, bad form! Also, Sonar complains
         // bitterly
 
-        StringBuffer buffer = new StringBuffer(decrypt(template));
+        StringBuilder builder = new StringBuilder(decrypt(template));
         Pattern pattern = Pattern.compile("\\$\\{([^\\}]+)\\}");
-        Matcher matcher = pattern.matcher(buffer);
+        Matcher matcher = pattern.matcher(builder);
         while (matcher.find()) {
             String variable = matcher.group(1);
             String value = properties.getProperty(variable);
@@ -184,11 +181,11 @@ public final class DefaultConfiguration implements Configuration, Cloneable {
             if (value == null) {
                 value = "";
             }
-            buffer.replace(matcher.start(), matcher.end(), value);
+            builder.replace(matcher.start(), matcher.end(), value);
 
             matcher.reset();
         }
-        return buffer.toString().trim();
+        return builder.toString().trim();
     }
 
     /**
@@ -379,7 +376,7 @@ public final class DefaultConfiguration implements Configuration, Cloneable {
      */
     @Override
     public int hashCode() {
-        return (properties == null ? 0 : properties.hashCode());
+        return properties == null ? 0 : properties.hashCode();
     }
 
     /**
@@ -487,7 +484,7 @@ public final class DefaultConfiguration implements Configuration, Cloneable {
         try {
             properties.load(is);
         } catch (IOException e) {
-            e.printStackTrace();
+            logger.warn("setProperties with inputStream got exception", e);
         }
     }
 
@@ -524,8 +521,8 @@ public final class DefaultConfiguration implements Configuration, Cloneable {
     @SuppressWarnings("nls")
     @Override
     public String toString() {
-        return String.format("Configuration: %d properties, keys:[%s]", properties.size(), properties.keySet()
-                .toString());
+        return String.format("Configuration: %d properties, keys:[%s]",
+                properties.size(), properties.keySet().toString());
     }
 
     /**
diff --git a/appc-common/src/main/java/org/openecomp/appc/exceptions/APPCException.java b/appc-common/src/main/java/org/openecomp/appc/exceptions/APPCException.java
index 808434d62..314d0a601 100644
--- a/appc-common/src/main/java/org/openecomp/appc/exceptions/APPCException.java
+++ b/appc-common/src/main/java/org/openecomp/appc/exceptions/APPCException.java
@@ -22,8 +22,6 @@
  * ============LICENSE_END=========================================================
  */
 
-
-
 package org.openecomp.appc.exceptions;
 
 /**
diff --git a/appc-common/src/main/java/org/openecomp/appc/exceptions/UnknownProviderException.java b/appc-common/src/main/java/org/openecomp/appc/exceptions/UnknownProviderException.java
index 1551f48d1..f3eb8a486 100644
--- a/appc-common/src/main/java/org/openecomp/appc/exceptions/UnknownProviderException.java
+++ b/appc-common/src/main/java/org/openecomp/appc/exceptions/UnknownProviderException.java
@@ -22,8 +22,6 @@
  * ============LICENSE_END=========================================================
  */
 
-
-
 package org.openecomp.appc.exceptions;
 
 /**
@@ -100,7 +98,10 @@ public class UnknownProviderException extends APPCException {
     * @param writableStackTrace
     *            whether or not the stack trace should be writable
     */
-   public UnknownProviderException(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace) {
+   public UnknownProviderException(String message,
+                                   Throwable cause,
+                                   boolean enableSuppression,
+                                   boolean writableStackTrace) {
        super(message, cause, enableSuppression, writableStackTrace);
    }
 
diff --git a/appc-common/src/main/java/org/openecomp/appc/logging/LoggingConstants.java b/appc-common/src/main/java/org/openecomp/appc/logging/LoggingConstants.java
index 9d6a32fe9..5c6d7b2b7 100644
--- a/appc-common/src/main/java/org/openecomp/appc/logging/LoggingConstants.java
+++ b/appc-common/src/main/java/org/openecomp/appc/logging/LoggingConstants.java
@@ -24,9 +24,21 @@
 
 package org.openecomp.appc.logging;
 
+/**
+ * Constant definition of logging
+ */
 public class LoggingConstants {
+    private LoggingConstants() {
+        throw new IllegalAccessError("LoggingConstants");
+    }
 
+    /**
+     * Constants of MDC property keys
+     */
     public static class MDCKeys {
+        private MDCKeys() {
+            throw new IllegalAccessError("MDCKeys");
+        }
 
         public static final String ERROR_CODE = "ErrorCode";
         public static final String ERROR_DESCRIPTION = "ErrorDescription";
@@ -44,12 +56,24 @@ public class LoggingConstants {
         public static final String TARGET_VIRTUAL_ENTITY = "TargetVirtualEntity";
     }
 
+    /**
+     * Constants of status code values
+     */
     public static class StatusCodes {
+        private StatusCodes() {
+            throw new IllegalAccessError("StatusCodes");
+        }
         public static final String COMPLETE = "COMPLETE";
         public static final String ERROR = "ERROR";
     }
 
+    /**
+     * Constants of APPC target names
+     */
     public static class TargetNames {
+        private TargetNames() {
+            throw new IllegalAccessError("TargetNames");
+        }
         public static final String APPC = "APPC";
         public static final String AAI = "A&AI";
         public static final String DB = "DataBase";
@@ -62,9 +86,21 @@ public class LoggingConstants {
         public static final String REQUEST_HANDLER = "RequestHandler";
     }
 
-    public static class TargetServiceNames{
+    /**
+     * Constants of targeted service names
+     */
+    public static class TargetServiceNames {
+        private TargetServiceNames() {
+            throw new IllegalAccessError("TargetServiceNames");
+        }
 
-        public static class AAIServiceNames{
+        /**
+         * Constants of AAI service names
+         */
+        public static class AAIServiceNames {
+            private AAIServiceNames() {
+                throw new IllegalAccessError("AAIServiceNames");
+            }
             public static final String QUERY = "query";
             public static final String GET_VNF_DATA = "getVnfData";
         }
diff --git a/appc-common/src/main/java/org/openecomp/appc/logging/LoggingUtils.java b/appc-common/src/main/java/org/openecomp/appc/logging/LoggingUtils.java
index 70c7fb1d2..65ea7893f 100644
--- a/appc-common/src/main/java/org/openecomp/appc/logging/LoggingUtils.java
+++ b/appc-common/src/main/java/org/openecomp/appc/logging/LoggingUtils.java
@@ -41,33 +41,43 @@ import java.time.temporal.ChronoUnit;
 import java.util.Date;
 import java.util.TimeZone;
 
-
-
+/**
+ * Logging utilities
+ */
 public class LoggingUtils {
 
     private final static EELFLogger errorLogger = EELFManager.getInstance().getErrorLogger();
     private final static EELFLogger auditLogger = EELFManager.getInstance().getAuditLogger();
     private final static EELFLogger metricLogger = EELFManager.getInstance().getMetricsLogger();
 
-    public static void logErrorMessage(String errorCode, String errorDescription, String targetEntity, String targetServiceName, String additionalMessage, String className) {
+    private LoggingUtils() {
+        throw new IllegalAccessError("LoggingUtils");
+    }
+
+    public static void logErrorMessage(String errorCode, String errorDescription, String targetEntity,
+                                       String targetServiceName, String additionalMessage, String className) {
         logError(errorCode, errorDescription, targetEntity, targetServiceName, additionalMessage, className);
     }
 
-    public static void logErrorMessage(String targetEntity, String targetServiceName, String additionalMessage, String className) {
+    public static void logErrorMessage(String targetEntity, String targetServiceName, String additionalMessage,
+                                       String className) {
         logError("", "", targetEntity, targetServiceName, additionalMessage, className);
     }
 
     public static void logErrorMessage(String targetServiceName, String additionalMessage, String className) {
-        logError("", "", LoggingConstants.TargetNames.APPC, targetServiceName, additionalMessage, className);
+        logError("", "", LoggingConstants.TargetNames.APPC, targetServiceName,
+                additionalMessage, className);
     }
 
-    private static void logError(String errorCode, String errorDescription, String targetEntity, String targetServiceName, String additionalMessage, String className) {
+    private static void logError(String errorCode, String errorDescription, String targetEntity,
+                                 String targetServiceName, String additionalMessage, String className) {
         populateErrorLogContext(errorCode, errorDescription, targetEntity, targetServiceName, className);
         errorLogger.error(additionalMessage == null ? "" : additionalMessage);
         cleanErrorLogContext();
     }
 
-    public static void logAuditMessage(Instant beginTimeStamp, Instant endTimeStamp, String code, String responseDescription, String className) {
+    public static void logAuditMessage(Instant beginTimeStamp, Instant endTimeStamp, String code,
+                                       String responseDescription, String className) {
         populateAuditLogContext(beginTimeStamp, endTimeStamp, code, responseDescription, className);
         auditLogger.info(EELFResourceManager.format(Msg.APPC_AUDIT_MSG,
                 MDC.get(MDC_SERVICE_NAME),
@@ -80,13 +90,15 @@ public class LoggingUtils {
         cleanAuditErrorContext();
     }
 
-    public static void auditInfo(Instant beginTimeStamp, Instant endTimeStamp, String code, String responseDescription, String className,EELFResolvableErrorEnum resourceId, String... arguments) {
+    public static void auditInfo(Instant beginTimeStamp, Instant endTimeStamp, String code, String responseDescription,
+                                 String className,EELFResolvableErrorEnum resourceId, String... arguments) {
         populateAuditLogContext(beginTimeStamp, endTimeStamp, code, responseDescription, className);
         auditLogger.info(resourceId,arguments);
         cleanAuditErrorContext();
     }
 
-    public static void auditWarn(Instant beginTimeStamp, Instant endTimeStamp, String code, String responseDescription, String className,EELFResolvableErrorEnum resourceId, String... arguments) {
+    public static void auditWarn(Instant beginTimeStamp, Instant endTimeStamp, String code, String responseDescription,
+                                 String className,EELFResolvableErrorEnum resourceId, String... arguments) {
         populateAuditLogContext(beginTimeStamp, endTimeStamp, code, responseDescription, className);
         auditLogger.warn(resourceId,arguments);
         cleanAuditErrorContext();
@@ -94,8 +106,11 @@ public class LoggingUtils {
 
 
 
-    public static void logMetricsMessage(Instant beginTimeStamp, Instant endTimeStamp, String targetEntity, String targetServiceName, String statusCode, String responseCode, String responseDescription, String className) {
-        populateMetricLogContext(beginTimeStamp, endTimeStamp, targetEntity, targetServiceName, statusCode, responseCode, responseDescription, className);
+    public static void logMetricsMessage(Instant beginTimeStamp, Instant endTimeStamp, String targetEntity,
+                                         String targetServiceName, String statusCode, String responseCode,
+                                         String responseDescription, String className) {
+        populateMetricLogContext(beginTimeStamp, endTimeStamp, targetEntity, targetServiceName, statusCode,
+                responseCode, responseDescription, className);
         metricLogger.info(EELFResourceManager.format(Msg.APPC_METRIC_MSG,
                 MDC.get(MDC_SERVICE_NAME),
                 MDC.get(LoggingConstants.MDCKeys.TARGET_VIRTUAL_ENTITY),
@@ -108,10 +123,11 @@ public class LoggingUtils {
         cleanMetricContext();
     }
 
-    private static void populateAuditLogContext(Instant beginTimeStamp, Instant endTimeStamp, String code, String responseDescription, String className) {
+    private static void populateAuditLogContext(Instant beginTimeStamp, Instant endTimeStamp, String code,
+                                                String responseDescription, String className) {
         populateTimeContext(beginTimeStamp, endTimeStamp);
         MDC.put(LoggingConstants.MDCKeys.RESPONSE_CODE, code);
-        MDC.put(LoggingConstants.MDCKeys.STATUS_CODE, code.equals("100") || code.equals("400") ?
+        MDC.put(LoggingConstants.MDCKeys.STATUS_CODE, "100".equals(code) || "400".equals(code) ?
                 LoggingConstants.StatusCodes.COMPLETE :
                 LoggingConstants.StatusCodes.ERROR);
         MDC.put(LoggingConstants.MDCKeys.RESPONSE_DESCRIPTION, responseDescription!=null?responseDescription:"");
@@ -126,7 +142,8 @@ public class LoggingUtils {
         MDC.remove(LoggingConstants.MDCKeys.CLASS_NAME);
     }
 
-    private static void populateErrorLogContext(String errorCode, String errorDescription, String targetEntity, String targetServiceName, String className) {
+    private static void populateErrorLogContext(String errorCode, String errorDescription, String targetEntity,
+                                                String targetServiceName, String className) {
         populateErrorContext(errorCode, errorDescription);
         populateTargetContext(targetEntity, targetServiceName!=null?targetServiceName:"");
         MDC.put(LoggingConstants.MDCKeys.CLASS_NAME, className!=null?className:"");
@@ -138,7 +155,9 @@ public class LoggingUtils {
         MDC.remove(LoggingConstants.MDCKeys.CLASS_NAME);
     }
 
-    private static void populateMetricLogContext(Instant beginTimeStamp, Instant endTimeStamp, String targetEntity, String targetServiceName, String statusCode, String responseCode, String responseDescription, String className) {
+    private static void populateMetricLogContext(Instant beginTimeStamp, Instant endTimeStamp, String targetEntity,
+                                                 String targetServiceName, String statusCode, String responseCode,
+                                                 String responseDescription, String className) {
         populateTimeContext(beginTimeStamp, endTimeStamp);
         populateTargetContext(targetEntity, targetServiceName);
         populateResponseContext(statusCode, responseCode, responseDescription);
diff --git a/appc-common/src/main/java/org/openecomp/appc/metadata/objects/DependencyModelIdentifier.java b/appc-common/src/main/java/org/openecomp/appc/metadata/objects/DependencyModelIdentifier.java
index f76823308..8b1b5870a 100644
--- a/appc-common/src/main/java/org/openecomp/appc/metadata/objects/DependencyModelIdentifier.java
+++ b/appc-common/src/main/java/org/openecomp/appc/metadata/objects/DependencyModelIdentifier.java
@@ -24,51 +24,67 @@
 
 package org.openecomp.appc.metadata.objects;
 
-
+/**
+ * Object of identifier for dependency model.
+ * Currently uses VNF type and catalog version
+ */
 public class DependencyModelIdentifier {
+    static final String TO_STRING_FORMAT = "DependencyModelIdentifier : vnfType = %s , catalogVersion = %s";
+    static final int prime = 31;
+
     private String vnfType;
     private String catalogVersion;
 
-    public DependencyModelIdentifier(String vnfType, String catalogVersion){
+    /**
+     * Constructor
+     * @param vnfType String of the VNF type
+     * @param catalogVersion String of the catalog version
+     */
+    public DependencyModelIdentifier(String vnfType, String catalogVersion) {
         this.vnfType = vnfType;
         this.catalogVersion = catalogVersion;
     }
 
-    public int hashCode(){
-        final int prime = 31;
+    @Override
+    public int hashCode() {
         int result = 1;
         result = result * prime + (this.vnfType == null ? 0 :this.vnfType.hashCode());
         result = result * prime + (this.catalogVersion == null ? 0 :this.catalogVersion.hashCode());
         return result;
     }
 
-    public boolean equals(Object obj){
-        if(obj ==null)
+    @Override
+    public boolean equals(Object obj) {
+        if (obj ==null) {
             return false;
-        if(!(obj instanceof DependencyModelIdentifier))
+        }
+        if (!(obj instanceof DependencyModelIdentifier)) {
             return false;
+        }
 
         DependencyModelIdentifier modelIdentifier = (DependencyModelIdentifier)obj;
-        if(this.vnfType == null){
-            if(modelIdentifier.vnfType !=null)
+        if (this.vnfType == null) {
+            if (modelIdentifier.vnfType !=null) {
                 return false;
-        }
-        else if(!this.vnfType.equals(modelIdentifier.vnfType))
+            }
+        } else if (!this.vnfType.equals(modelIdentifier.vnfType)) {
             return false;
+        }
 
-        if(this.catalogVersion == null){
-            if(modelIdentifier.catalogVersion !=null)
+        if (this.catalogVersion == null) {
+            if (modelIdentifier.catalogVersion !=null) {
                 return false;
-        }
-        else if(!this.catalogVersion.equals(modelIdentifier.catalogVersion))
+            }
+        } else if (!this.catalogVersion.equals(modelIdentifier.catalogVersion)) {
             return false;
+        }
 
         return true;
     }
 
     @Override
     public String toString() {
-        return "DependencyModelIdentifier : vnfType = "+vnfType + " , catalogVersion = " +catalogVersion;
+        return String.format(TO_STRING_FORMAT, vnfType, catalogVersion);
     }
 
     public String getVnfType() {