Merge branch '273-service-exceptions' into 'master'

Services should throw exceptions for startup errors

Fixes #273

See merge request !134

briar-api/src/org/briarproject/api/db/DatabaseComponent.java

@@ -19,7 +19,6 @@ import org.briarproject.api.sync.Offer;
 import org.briarproject.api.sync.Request;
 import org.briarproject.api.transport.TransportKeys;
 
-import java.io.IOException;
 import java.util.Collection;
 import java.util.Map;
 
@@ -37,7 +36,7 @@ public interface DatabaseComponent {
 	/**
 	 * Waits for any open transactions to finish and closes the database.
 	 */
-	void close() throws DbException, IOException;
+	void close() throws DbException;
 
 	/**
 	 * Starts a new transaction and returns an object representing it.

briar-api/src/org/briarproject/api/lifecycle/Service.java

@@ -3,14 +3,14 @@ package org.briarproject.api.lifecycle;
 public interface Service {
 
 	/**
-	 * Starts the service and returns true if it started successfully.
-	 * This method must not be called concurrently with {@link #stop()}.
+	 * Starts the service.This method must not be called concurrently with
+	 * {@link #stopService()}.
 	 */
-	public boolean start();
+	void startService() throws ServiceException;
 
 	/**
-	 * Stops the service and returns true if it stopped successfully.
-	 * This method must not be called concurrently with {@link #start()}.
+	 * Stops the service. This method must not be called concurrently with
+	 * {@link #startService()}.
 	 */
-	public boolean stop();
+	void stopService() throws ServiceException;
 }

briar-api/src/org/briarproject/api/lifecycle/ServiceException.java

@@ -0,0 +1,15 @@
+package org.briarproject.api.lifecycle;
+
+/**
+ * An exception that indicates an error starting or stopping a {@link Service}.
+ */
+public class ServiceException extends Exception {
+
+	public ServiceException() {
+		super();
+	}
+
+	public ServiceException(Throwable cause) {
+		super(cause);
+	}
+}