Refactored config file resource loading to make it easier to load config files from class path when embedding.

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

@@ -0,0 +1,41 @@
+package io.moquette.server.config;
+
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.Reader;
+
+public class ClasspathResourceLoader implements IResourceLoader {
+
+    private final String defaultResource;
+    private final ClassLoader classLoader;
+
+    public ClasspathResourceLoader() {
+        this(IConfig.DEFAULT_CONFIG);
+    }
+
+    public ClasspathResourceLoader(String defaultResource) {
+        this(defaultResource, Thread.currentThread().getContextClassLoader());
+    }
+
+    public ClasspathResourceLoader(String defaultResource, ClassLoader classLoader) {
+        this.defaultResource = defaultResource;
+        this.classLoader = classLoader;
+    }
+
+    @Override
+    public Reader loadDefaultResource() {
+        return loadResource(defaultResource);
+    }
+
+    @Override
+    public Reader loadResource(String relativePath) {
+        InputStream is = this.classLoader.getResourceAsStream(relativePath);
+        return is != null ? new InputStreamReader(is) : null;
+    }
+
+    @Override
+    public String getName() {
+        return "classpath resource";
+    }
+
+}