Added persistence for configuration

pom.xml

@@ -43,6 +43,11 @@
             <artifactId>jackson-databind</artifactId>
             <version>2.6.0</version>
         </dependency>
+		<dependency>
+		  <groupId>com.cedarsoftware</groupId>
+		  <artifactId>json-io</artifactId>
+		  <version>4.1.6</version>
+		</dependency>
 	</dependencies>
 	
 	<build>

src/main/java/com/bwssytems/HABridge/dao/DeviceRepository.java

@@ -1,24 +1,48 @@
 package com.bwssytems.HABridge.dao;
 
+import java.io.BufferedReader;
+import java.io.FileReader;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.io.StringReader;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Random;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
+import com.bwssytems.HABridge.JsonTransformer;
 import com.bwssytems.HABridge.dao.DeviceDescriptor;
+import com.google.gson.Gson;
+import com.google.gson.stream.JsonReader;
 
 import java.util.List;
+import java.util.ListIterator;
 /*
- * This is an in memory list to manage the configured devices. 
+ * This is an in memory list to manage the configured devices and saves the list as a JSON string to a file for later  
- * 
+ * loading.
  */
 public class DeviceRepository {
 	Map<String, DeviceDescriptor> devices;
     final Random random = new Random();
+    final String repositoryPath = "device.db";
+    final Logger log = LoggerFactory.getLogger(DeviceRepository.class);
 	
     public DeviceRepository() {
 		super();
+		String jsonContent = repositoryReader(repositoryPath);
 		devices = new HashMap<String, DeviceDescriptor>();
+		if(jsonContent != null)
+		{
+			List<DeviceDescriptor> list = readJsonStream(jsonContent);
+			ListIterator<DeviceDescriptor> theIterator = list.listIterator();
+			DeviceDescriptor theDevice = null;
+			while (theIterator.hasNext()) {
+				theDevice = theIterator.next();
+				put(Integer.parseInt(theDevice.getId()), theDevice);
+			}
+		}
 	}
     
 	public List<DeviceDescriptor> findAll() {
@@ -33,22 +57,130 @@ public class DeviceRepository {
 	
 	public DeviceDescriptor findOne(String id) {
     	return devices.get(id);	
+    }
     
+	private void put(int id, DeviceDescriptor aDescriptor) {
+        devices.put(String.valueOf(id),aDescriptor);
     }
     
 	public void save(DeviceDescriptor aDescriptor) {
         int id = random.nextInt(Integer.MAX_VALUE);
         aDescriptor.setId(String.valueOf(id));
-        devices.put(String.valueOf(id),aDescriptor);
+        put(id, aDescriptor);
+    	JsonTransformer aRenderer = new JsonTransformer();
+    	String  jsonValue = aRenderer.render(findAll());
+        repositoryWriter(jsonValue, repositoryPath);
     }
     
 	public String delete(DeviceDescriptor aDescriptor) {
         if (aDescriptor != null) {
         	devices.remove(aDescriptor.getId());
+        	JsonTransformer aRenderer = new JsonTransformer();
+        	String  jsonValue = aRenderer.render(findAll());
+            repositoryWriter(jsonValue, repositoryPath);
             return "Device with id '" + aDescriptor.getId() + "' deleted";
         } else {
             return "Device not found";
         }
 
     }
+	
+	private void repositoryWriter(String content, String filePath) {
+		FileWriter writer = null;
+
+		try {
+			writer = new FileWriter(filePath, false);
+			writer.write(content);
+		} catch (IOException e) {
+			log.error("Error writing the file: " + filePath + " message: " + e.getMessage(), e);
+		} finally {
+			if (writer != null) {
+				try {
+					writer.close();
+				} catch (IOException e) {
+					log.error("Error closing the file (w): " + filePath + " message: " + e.getMessage(), e);
+				}
+			}
+		}
+	}
+	
+	private String repositoryReader(String filePath) {
+		FileReader reader = null;
+		BufferedReader br = null;
+		String content = null;
+		try {
+			reader = new FileReader(filePath);
+			br = new BufferedReader(reader);
+			content = br.readLine();
+		} catch (IOException e) {
+			log.error("Error reading the file: " + filePath + " message: " + e.getMessage(), e);
+		} finally {
+			if (reader != null) {
+				try {
+					br.close();
+					reader.close();
+				} catch (IOException e) {
+					log.error("Error closing the file (r): " + filePath + " message: " + e.getMessage(), e);
+				}
+			}
+		}
+		return content;
+	}
+
+	private List<DeviceDescriptor> readJsonStream(String context) {
+		JsonReader reader = new JsonReader(new StringReader(context));
+		List<DeviceDescriptor> theDescriptors = null;
+		try {
+			theDescriptors = readDescriptorArray(reader);
+		} catch (IOException e) {
+			log.error("Error reading json array: " + context + " message: " + e.getMessage(), e);
+		} finally {
+			try {
+				reader.close();
+			} catch  (IOException e) {
+				log.error("Error closing json reader: " + context + " message: " + e.getMessage(), e);
+			}
+		}
+		return theDescriptors;
+	}
+
+	public List<DeviceDescriptor> readDescriptorArray(JsonReader reader) throws IOException {
+		List<DeviceDescriptor> descriptors = new ArrayList<DeviceDescriptor>();
+
+		reader.beginArray();
+		while (reader.hasNext()) {
+			descriptors.add(readDescriptor(reader));
+		}
+		reader.endArray();
+		return descriptors;
+	}
+
+	public DeviceDescriptor readDescriptor(JsonReader reader) throws IOException {
+        DeviceDescriptor deviceEntry = new DeviceDescriptor();
+
+		reader.beginObject();
+		while (reader.hasNext()) {
+		       String name = reader.nextName();
+		       if (name.equals("id")) {
+			        deviceEntry.setId(reader.nextString());
+			    	log.debug("Read a Device - device json id: " + deviceEntry.getId());
+		       } else if (name.equals("name")) {
+			        deviceEntry.setName(reader.nextString());
+			    	log.debug("Read a Device - device json name: " + deviceEntry.getName());
+		       } else if (name.equals("deviceType")) {
+			        deviceEntry.setDeviceType(reader.nextString());
+			    	log.debug("Read a Device - device json type:" + deviceEntry.getDeviceType());
+		       } else if (name.equals("offUrl")) {
+			        deviceEntry.setOffUrl(reader.nextString());
+			    	log.debug("Read a Device - device json off URL:" + deviceEntry.getOffUrl());
+		       } else if (name.equals("onUrl")) {
+			        deviceEntry.setOnUrl(reader.nextString());
+			    	log.debug("Read a Device - device json on URL:" + deviceEntry.getOnUrl());
+		       } else {
+		         reader.skipValue();
+		       }
+		}
+		reader.endObject();
+		return deviceEntry;
+	}
 }