Isolate json-io usage behind a JSON bridge.

src/blacksmyth/personalfinancier/control/JSonFileAdapter.java

@@ -10,43 +10,43 @@
 
 package blacksmyth.personalfinancier.control;
 
-import java.io.IOException;
-
 import blacksmyth.general.FileUtilities;
-
-import com.cedarsoftware.util.io.JsonReader;
-import com.cedarsoftware.util.io.JsonWriter;
+import blacksmyth.personalfinancier.dependencies.IJSonSerialisationBridge;
+import blacksmyth.personalfinancier.dependencies.JSonBridge;
 
 /**
- * An adapter through to a 3rd-party JSON Serialization library.
- * All access to JSson functionality should go through this adapter.
- * @author linds
+ * An adapter class that transfers state between instantiated objects and file-serialised
+ * object state via a 3rd-party JSON Serialization library.
  */
+
 public class JSonFileAdapter<T> implements IPersonalFinancierFileAdapter<T> {
 
+  private IJSonSerialisationBridge<T> jsonBridge;
+
+  public JSonFileAdapter() {
+    init(new JSonBridge<T>());
+  }
+
+  public JSonFileAdapter(IJSonSerialisationBridge<T> bridge) {
+    init(bridge);
+  }
+
+  private void init(IJSonSerialisationBridge<T> bridge) {
+    this.jsonBridge = bridge;
+  }
+
   @Override
   public void toFileFromObject(String filePath, T t) {
-    try {
-      FileUtilities.saveTextFile(
-          filePath, 
-          JsonWriter.formatJson(
-              JsonWriter.objectToJson(t)
-          )
-      );
-
-    } catch (IOException e) {
-    }
+    FileUtilities.saveTextFile(
+        filePath, 
+        jsonBridge.toJSon(t)
+    );
   }
 
   @Override
-  @SuppressWarnings("unchecked")
   public T toObjectFromFile(String filePath) {
-    try {
-      return (T) JsonReader.jsonToJava(
-          FileUtilities.loadTextFile(filePath)
-      );
-    } catch (IOException e) {
-      return null;
-    }
+    return jsonBridge.fromJson(
+      FileUtilities.loadTextFile(filePath)
+    );
   }
 }

src/blacksmyth/personalfinancier/dependencies/IJSonSerialisationBridge.java

@@ -0,0 +1,37 @@
+/**
+ * Copyright (c) 2012, Lindsay Bradford and other Contributors.
+ * All rights reserved.
+ * 
+ * This program and the accompanying materials  are made available 
+ * under the terms of the BSD 3-Clause licence  which accompanies 
+ * this distribution, and is available at
+ * http://opensource.org/licenses/BSD-3-Clause
+ */
+
+package blacksmyth.personalfinancier.dependencies;
+
+/**
+ * An interface defining the 'Abstraction' of the Bridge pattern, allowing a bridge 
+ * of all needed functionality between the application and some 3rd-party JSON library 
+ * that the application depends on.
+ *
+ * @param <T> The type of objects that this class will bridge JSON serialisation for.
+ */
+
+public interface IJSonSerialisationBridge<T> {
+
+    /**
+     * Converts an object of type T to a JSON serialisation string of its content.
+     * @param object
+     * @return JSON serialisation of object state.
+     */
+
+    public String toJSon(T object);
+
+    /**
+     * Covnerts a JSON serialisation of an object of type T into an instance of that object.
+     * @param jsonContent
+     * @return an object instantiated with the state encoded in jsonContent.
+     */
+    public T fromJson(String jsonContent);
+}

src/blacksmyth/personalfinancier/dependencies/JSonBridge.java

@@ -0,0 +1,38 @@
+/**
+ * Copyright (c) 2012, Lindsay Bradford and other Contributors.
+ * All rights reserved.
+ * 
+ * This program and the accompanying materials  are made available 
+ * under the terms of the BSD 3-Clause licence  which accompanies 
+ * this distribution, and is available at
+ * http://opensource.org/licenses/BSD-3-Clause
+ */
+
+package blacksmyth.personalfinancier.dependencies;
+
+/**
+ * A class implementing the 'refined abstraction class' of the Bridge pattern, allowing a 
+ * bridge all needed functionality between the application and the open-source JSON library json-io 
+ * (https://code.google.com/p/json-io/)
+ *
+ * @param <T> The type of objects that this class will bridge JSON serialisation for.
+ */
+
+public class JSonBridge<T> implements IJSonSerialisationBridge<T> {
+
+  private IJSonSerialisationBridge<T> bridge; 
+
+  public JSonBridge() {
+    this.bridge = new JSonIoBridge<T>();
+  }
+
+  @Override
+  public String toJSon(T object) {
+    return bridge.toJSon(object);
+  }
+
+  @Override
+  public T fromJson(String jsonContent) {
+    return bridge.fromJson(jsonContent);
+  }
+}

src/blacksmyth/personalfinancier/dependencies/JSonIoBridge.java

@@ -0,0 +1,51 @@
+/**
+ * Copyright (c) 2012, Lindsay Bradford and other Contributors.
+ * All rights reserved.
+ * 
+ * This program and the accompanying materials  are made available 
+ * under the terms of the BSD 3-Clause licence  which accompanies 
+ * this distribution, and is available at
+ * http://opensource.org/licenses/BSD-3-Clause
+ */
+
+package blacksmyth.personalfinancier.dependencies;
+
+import java.io.IOException;
+
+import com.cedarsoftware.util.io.JsonWriter;
+import com.cedarsoftware.util.io.JsonReader;
+
+/**
+ * A class implementing the 'Concrete Implementor class' of the Bridge pattern, allowing a bridge 
+ * of all needed functionality between the application and the open-source JSON library json-io 
+ * (https://code.google.com/p/json-io/)
+ *
+ * @param <T> The type of objects that this class will bridge JSON serialisation for.
+ */
+
+public class JSonIoBridge<T> implements IJSonSerialisationBridge<T> {
+
+  @Override
+  public String toJSon(T object) {
+    try {
+      return JsonWriter.formatJson(
+        JsonWriter.objectToJson(object)
+      );
+    } catch (IOException ioe) {
+      return null;
+    }
+  }
+
+  @SuppressWarnings("unchecked")
+  @Override
+  public T fromJson(String jsonContent) {
+    try {
+      return (T) JsonReader.jsonToJava(
+          jsonContent
+      );
+    } catch (IOException e) {
+      return null;
+    }
+  }
+
+}

src/blacksmyth/personalfinancier/model/IFileHandlerModel.java

@@ -12,6 +12,5 @@
 
 public interface IFileHandlerModel<T> {
   public void fromSerializable(T t);
-
   public T toSerializable();
 }