Error logging for Unsuccessful L10n Fetch ( plus code clean up)

src/main/java/com/vmware/vipclient/i18n/base/cache/MessageCacheItem.java

@@ -40,10 +40,6 @@ public void addCacheData(String key, String value) {
 		this.cachedData.put(key, value);
 	}
 
-	public boolean isCachedDataEmpty() {
-		return this.cachedData.isEmpty();
-	}
-
 	public synchronized void addCachedData(Map<String, String> cachedData) {
 		if (cachedData != null) 
 			this.cachedData.putAll(cachedData);

src/main/java/com/vmware/vipclient/i18n/common/ConstantsMsg.java

@@ -12,5 +12,6 @@ public class ConstantsMsg {
     public static final String SERVER_RETURN_ERROR  = "Server returned error! Status: %d. Message: %s";
     public static final String SERVER_CONTENT_ERROR = "The content from server is wrong!";
     public static final String UNKNOWN_ERROR        = "Unknown error.";
+    public static final String GET_MESSAGES_FAILED  = "Failed to get messages for component {0}, locale: {1}.";
 
 }

src/main/java/com/vmware/vipclient/i18n/messages/service/ComponentService.java

@@ -6,6 +6,8 @@
 
 import java.util.ListIterator;
 import java.util.Map;
+import java.util.concurrent.Callable;
+import java.util.concurrent.FutureTask;
 
 import org.json.simple.JSONValue;
 import org.json.simple.parser.ParseException;
@@ -15,12 +17,13 @@
 import com.vmware.vipclient.i18n.VIPCfg;
 import com.vmware.vipclient.i18n.base.DataSourceEnum;
 import com.vmware.vipclient.i18n.base.cache.MessageCacheItem;
-import com.vmware.vipclient.i18n.base.cache.CacheMode;
-import com.vmware.vipclient.i18n.base.cache.persist.DiskCacheLoader;
-import com.vmware.vipclient.i18n.base.cache.persist.Loader;
+import com.vmware.vipclient.i18n.common.ConstantsMsg;
 import com.vmware.vipclient.i18n.messages.api.opt.server.ComponentBasedOpt;
 import com.vmware.vipclient.i18n.messages.dto.MessagesDTO;
+import com.vmware.vipclient.i18n.util.ConstantsKeys;
+import com.vmware.vipclient.i18n.util.FormatUtils;
 import com.vmware.vipclient.i18n.util.JSONUtils;
+import com.vmware.vipclient.i18n.util.LocaleUtility;
 
 public class ComponentService {
     private MessagesDTO dto    = null;
@@ -40,39 +43,74 @@ public ComponentService(MessagesDTO dto) {
     public void getMessages(final MessageCacheItem cacheItem, ListIterator<DataSourceEnum> msgSourceQueueIter) {
     	if (!msgSourceQueueIter.hasNext()) 
     		return;
+
+    	long timestampOld = cacheItem.getTimestamp();
     	DataSourceEnum dataSource = (DataSourceEnum) msgSourceQueueIter.next();
     	dataSource.createMessageOpt(dto).getComponentMessages(cacheItem);
+    	long timestampNew = cacheItem.getTimestamp();
 
-    	// If failed to get messages from the dataSource, try the next dataSource in the queue
-    	if (cacheItem.getCachedData().isEmpty()) {
-    		getMessages(cacheItem, msgSourceQueueIter);
+    	// If failed to get messages from the data source
+    	if (timestampNew == timestampOld) {
+    		// Try the next dataSource in the queue
+    		if (msgSourceQueueIter.hasNext()) {
+    			getMessages(cacheItem, msgSourceQueueIter);
+    		// If no more data source in queue, log the error. This means that neither online nor offline fetch succeeded.
+    		} else {
+    			logger.error(FormatUtils.format(ConstantsMsg.GET_MESSAGES_FAILED, LocaleUtility.getDefaultLocale(), 
+    					dto.getComponent(), dto.getLocale()));
+    		}
     	}
     }
-
+    
     public Map<String, String> getComponentTranslation() {
-        CacheService cs = new CacheService(dto);
-
-        if (cs.isContainComponent()) {
-        	return cs.getCacheOfComponent().getCachedData();
-        } else {
-	        // Messages are not cached in memory, so try to look in disk cache
-	        if (VIPCfg.getInstance().getCacheMode() == CacheMode.DISK) {
-	            Loader loader = VIPCfg.getInstance().getCacheManager()
-	                    .getLoaderInstance(DiskCacheLoader.class);
-	            Map<String, String> cachedMessages = loader.load(dto.getCompositStrAsCacheKey());
-	            if (cachedMessages != null) // Messages are in disk cache
-	            	return cachedMessages;
-	        }
-
-			// Prepare a new CacheItem to store cache properties
-	        MessageCacheItem cacheItem = new MessageCacheItem();
-			// Pass this cacheItem to getMessages so that it will be populated from the http request
-			this.getMessages(cacheItem, VIPCfg.getInstance().getMsgOriginsQueue().listIterator());
-			// Store the messages and properties in cache using a single CacheItem object
-			cs.addCacheOfComponent(cacheItem);
-			return cacheItem.getCachedData(); 
-        }
+    	return fetchMessages().getCachedData();
+    }
+
+    public MessageCacheItem fetchMessages() {
+    	CacheService cacheService = new CacheService(dto);
+    	Map<String, String> cacheOfComponent = null;
+    	MessageCacheItem cacheItem = null;
+    	if (cacheService.isContainComponent()) { // Item is in cache
+    		cacheItem = cacheService.getCacheOfComponent();
+    		cacheOfComponent = cacheItem.getCachedData();
+    		if (cacheItem.isExpired()) { // cacheItem has expired
+    			// Update the cache in a separate thread
+    			populateCacheTask(cacheService, dto, cacheItem); 		
+    		}
+    	} else { // Item is not in cache
+    		// Create a new cacheItem object to be stored in cache
+    		cacheItem = new MessageCacheItem();  
+    		getMessages(cacheItem, VIPCfg.getInstance().getMsgOriginsQueue().listIterator());
+    		cacheOfComponent = cacheItem.getCachedData();
+
+    		if (cacheOfComponent != null && !cacheOfComponent.isEmpty()) {
+    			cacheService.addCacheOfComponent(cacheItem);
+    		}
+    	} 
+    	return cacheItem;
     }
+
+	private void populateCacheTask(final CacheService cacheService, MessagesDTO dto, MessageCacheItem cacheItem) {
+		Callable<MessageCacheItem> callable = () -> {
+    		try {
+
+    			// Pass cacheItem to getMessages so that:
+				// 1. A previously stored etag, if any, can be used for the next HTTP request.
+				// 2. CacheItem properties such as etag, timestamp and maxAgeMillis can be refreshed 
+				// 	 with new properties from the next HTTP response.	
+				getMessages(cacheItem, VIPCfg.getInstance().getMsgOriginsQueue().listIterator());
+
+    			return cacheItem;
+    		} catch (Exception e) { 
+    			// To make sure that the thread will close 
+    			// even when an exception is thrown
+    			return null;
+		    }
+		};
+		FutureTask<MessageCacheItem> task = new FutureTask<MessageCacheItem>(callable); 
+		Thread thread = new Thread(task);
+		thread.start();	
+	}
 
     public boolean isComponentAvailable() {
         boolean r = false;

src/main/java/com/vmware/vipclient/i18n/messages/service/StringService.java

@@ -7,8 +7,6 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.concurrent.Callable;
-import java.util.concurrent.FutureTask;
 
 import org.json.simple.JSONObject;
 import org.json.simple.JSONValue;
@@ -33,7 +31,7 @@ public class StringService {
     public String getString(MessagesDTO dto) {
     	String key = dto.getKey();
 
-    	MessageCacheItem cacheItem = fetchMessages(dto);
+    	MessageCacheItem cacheItem = new ComponentService(dto).fetchMessages();
 
     	// If failed to get MessageCacheItem of a non-default locale, 
     	// use MessageCacheItem of the default locale instead. 
@@ -42,11 +40,11 @@ public String getString(MessagesDTO dto) {
 			MessagesDTO defaultLocaleDTO = new MessagesDTO(dto.getComponent(), 
 					dto.getKey(), dto.getSource(), LocaleUtility.getDefaultLocale().toLanguageTag(), null);
 			// MessageCacheItem of the default locale
-			cacheItem = fetchMessages(defaultLocaleDTO);
+			cacheItem = new ComponentService(defaultLocaleDTO).fetchMessages();
 
 			// The MessageCacheItem for the requested locale will be a reference 
 			// to the MessageCacheItem of the default locale 
-			if (!cacheItem.isCachedDataEmpty()) {
+			if (!cacheItem.getCachedData().isEmpty()) {
 				CacheService cacheService = new CacheService(dto);
 				cacheService.addCacheOfComponent(cacheItem);
 				cacheOfComponent = cacheItem.getCachedData();
@@ -56,55 +54,6 @@ public String getString(MessagesDTO dto) {
 
     }
 
-    public MessageCacheItem fetchMessages(MessagesDTO dto) {
-    	CacheService cacheService = new CacheService(dto);
-    	Map<String, String> cacheOfComponent = null;
-    	MessageCacheItem cacheItem = null;
-    	if (cacheService.isContainComponent()) { // Item is in cache
-    		cacheItem = cacheService.getCacheOfComponent();
-    		cacheOfComponent = cacheItem.getCachedData();
-    		if (cacheItem.isExpired()) { // cacheItem has expired
-    			// Update the cache in a separate thread
-    			populateCacheTask(cacheService, dto, cacheItem); 		
-    		}
-    	} else { // Item is not in cache
-    		// Create a new cacheItem object to be stored in cache
-    		cacheItem = new MessageCacheItem();   		
-    		cacheOfComponent = populateCache(cacheService, dto, cacheItem).getCachedData();
-
-    		if (cacheOfComponent != null && !cacheOfComponent.isEmpty()) {
-    			cacheService.addCacheOfComponent(cacheItem);
-    		}
-    	} 
-    	return cacheItem;
-    }
-
-	private void populateCacheTask(final CacheService cacheService, MessagesDTO dto, MessageCacheItem cacheItem) {
-		Callable<MessageCacheItem> callable = () -> {
-    		try {
-		    	// Use the cacheProps that is already in the cache.
-    			MessageCacheItem updatedCacheItem = populateCache(cacheService, dto, cacheItem);
-    			return updatedCacheItem;
-    		} catch (Exception e) { 
-    			// To make sure that the thread will close 
-    			// even when an exception is thrown
-    			return null;
-		    }
-		};
-		FutureTask<MessageCacheItem> task = new FutureTask<MessageCacheItem>(callable); 
-		Thread thread = new Thread(task);
-		thread.start();	
-	}
-
-	private MessageCacheItem populateCache(CacheService cacheService, MessagesDTO dto, MessageCacheItem cacheItem) {
-    	// Pass cacheitem to getMessages so that:
-		// 1. A previously stored etag, if any, can be used for the next HTTP request.
-		// 2. CacheItem properties such as etag, timestamp and maxAgeMillis can be refreshed 
-		// 	 with new properties from the next HTTP response.	
-		new ComponentService(dto).getMessages(cacheItem, VIPCfg.getInstance().getMsgOriginsQueue().listIterator());
-
-		return cacheItem;
-    }
 
     public String postString(MessagesDTO dto) {
         String r = "";

src/main/java/com/vmware/vipclient/i18n/util/ConstantsKeys.java

@@ -67,5 +67,4 @@ public class ConstantsKeys {
     public static final String      DISPLAY_NAME                       = "displayName";
     public static final String      JSON_KEYSET                        = "jsonkeyset";
     public static final String      TRANSLATION_STATUS                 = "translationStatus";
-
 }