Improve logging of package io.moquette.server.config

broker/src/main/java/io/moquette/server/config/ClasspathResourceLoader.java

@@ -4,8 +4,13 @@ import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.Reader;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 public class ClasspathResourceLoader implements IResourceLoader {
 
+	private static final Logger LOG = LoggerFactory.getLogger(ClasspathResourceLoader.class);
+	
     private final String defaultResource;
     private final ClassLoader classLoader;
 
@@ -29,6 +34,7 @@ public class ClasspathResourceLoader implements IResourceLoader {
 
     @Override
     public Reader loadResource(String relativePath) {
+    	LOG.info("Loading resource. RelativePath = {}.", relativePath);
         InputStream is = this.classLoader.getResourceAsStream(relativePath);
         return is != null ? new InputStreamReader(is) : null;
     }

broker/src/main/java/io/moquette/server/config/FileResourceLoader.java

@@ -5,8 +5,13 @@ import java.io.FileNotFoundException;
 import java.io.FileReader;
 import java.io.Reader;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 public class FileResourceLoader implements IResourceLoader {
 
+	private static final Logger LOG = LoggerFactory.getLogger(FileResourceLoader.class);
+	
     private final File defaultFile;
     private final String parentPath;
 
@@ -42,12 +47,15 @@ public class FileResourceLoader implements IResourceLoader {
     }
 
     public Reader loadResource(File f) {
+    	LOG.info("Loading file. Path = {}.", f.getAbsolutePath());
         if (f.isDirectory()) {
+        	LOG.error("The given file is a directory. Path = {}.", f.getAbsolutePath());
             throw new ResourceIsDirectoryException("File \"" + f + "\" is a directory!");
         }
         try {
             return new FileReader(f);
         } catch (FileNotFoundException e) {
+        	LOG.error("The file does not exist. Path = {}.", f.getAbsolutePath());
             return null;
         }
     }

broker/src/main/java/io/moquette/server/config/ResourceLoaderConfig.java

@@ -38,19 +38,38 @@ public class ResourceLoaderConfig extends IConfig {
 
     public ResourceLoaderConfig(IResourceLoader resourceLoader, String configName) {
         this.resourceLoader = resourceLoader;
-        Reader configReader = configName != null ? resourceLoader.loadResource(configName) : resourceLoader.loadDefaultResource();
-        if (configReader == null) {
-            throw new IllegalArgumentException(
-              "Can't locate " + resourceLoader.getName() + " \"" + configName + "\"");
+        
+        /*
+		 * If we use a conditional operator, the loadResource() and the
+		 * loadDefaultResource() methods will be always called. This makes the
+		 * log traces confusing.
+		 */
+        
+        Reader configReader;
+        if (configName != null) {
+        	configReader = resourceLoader.loadResource(configName);
+        } else {
+        	configReader = resourceLoader.loadDefaultResource();
         }
+        
+        if (configReader == null) {
+        	LOG.error("The resource loader returned no configuration reader. ResourceLoader = {}, configName = {}.",
+					resourceLoader.getName(), configName);
+			throw new IllegalArgumentException("Can't locate " + resourceLoader.getName() + " \"" + configName + "\"");
+        }
+        
+        LOG.info("Parsing configuration properties. ResourceLoader = {}, configName = {}.", resourceLoader.getName(),
+				configName);
         ConfigurationParser confParser = new ConfigurationParser();
         m_properties = confParser.getProperties();
         assignDefaults();
-        try {
-            confParser.parse(configReader);
-        } catch (ParseException pex) {
-            LOG.warn("An error occurred in parsing configuration, fallback on default configuration", pex);
-        }
+		try {
+			confParser.parse(configReader);
+		} catch (ParseException pex) {
+			LOG.warn(
+					"Unable to parse configuration properties. Using default configuration. ResourceLoader = {}, configName = {}, cause = {}, errorMessage = {}.",
+					resourceLoader.getName(), configName, pex.getCause(), pex.getMessage());
+		}
     }
 
     @Override