Introduce #close hook

src/main/java/io/bitsquare/BitsquareUI.java

@@ -17,14 +17,12 @@
 
 package io.bitsquare;
 
-import io.bitsquare.btc.WalletFacade;
 import io.bitsquare.di.BitsquareModule;
 import io.bitsquare.gui.AWTSystemTray;
 import io.bitsquare.gui.Navigation;
 import io.bitsquare.gui.components.Popups;
 import io.bitsquare.gui.util.ImageUtil;
 import io.bitsquare.gui.util.Profiler;
-import io.bitsquare.msg.MessageFacade;
 import io.bitsquare.persistence.Persistence;
 import io.bitsquare.settings.Settings;
 import io.bitsquare.user.User;
@@ -53,11 +51,13 @@ public class BitsquareUI extends Application {
     private static final Logger log = LoggerFactory.getLogger(BitsquareUI.class);
 
     private static Stage primaryStage;
-    private WalletFacade walletFacade;
-    private MessageFacade messageFacade;
 
-    public void BitsquareUI() {
-        Profiler.init();
+    private final BitsquareModule bitsquareModule;
+    private final Injector injector;
+
+    public BitsquareUI() {
+        this.bitsquareModule = new BitsquareModule();
+        this.injector = Guice.createInjector(bitsquareModule);
     }
 
     public static Stage getPrimaryStage() {
@@ -78,15 +78,10 @@ public class BitsquareUI extends Application {
             log.error(e.getMessage());
         }
 
-        final Injector injector = Guice.createInjector(new BitsquareModule());
 
         // currently there is not SystemTray support for java fx (planned for version 3) so we use the old AWT
         AWTSystemTray.createSystemTray(primaryStage, injector.getInstance(ActorSystem.class), this);
 
-        walletFacade = injector.getInstance(WalletFacade.class);
-        messageFacade = injector.getInstance(MessageFacade.class);
-        Profiler.printMsgWithTime("Bitsquare: messageFacade, walletFacade created");
-
         // apply stored data
         final User user = injector.getInstance(User.class);
         final Settings settings = injector.getInstance(Settings.class);
@@ -149,11 +144,8 @@ public class BitsquareUI extends Application {
     }
 
     @Override
-    public void stop() throws Exception {
-        walletFacade.shutDown();
-        messageFacade.shutDown();
-
-        super.stop();
+    public void stop() {
+        bitsquareModule.close(injector);
         System.exit(0);
     }
 }

src/main/java/io/bitsquare/btc/BitcoinModule.java

@@ -24,7 +24,7 @@ import org.bitcoinj.params.MainNetParams;
 import org.bitcoinj.params.RegTestParams;
 import org.bitcoinj.params.TestNet3Params;
 
-import com.google.inject.AbstractModule;
+import com.google.inject.Injector;
 
 import java.util.Properties;
 
@@ -49,6 +49,11 @@ public class BitcoinModule extends AbstractBitsquareModule {
         bind(NetworkParameters.class).toInstance(network());
     }
 
+    @Override
+    public void doClose(Injector injector) {
+        injector.getInstance(WalletFacade.class).shutDown();
+    }
+
     private NetworkParameters network() {
             String networkName = properties.getProperty("networkType", defaultNetwork.name());
 

src/main/java/io/bitsquare/di/AbstractBitsquareModule.java

@@ -17,15 +17,49 @@
 
 package io.bitsquare.di;
 
+import com.google.common.collect.Sets;
+
 import com.google.inject.AbstractModule;
+import com.google.inject.Injector;
 
 import java.util.Properties;
+import java.util.Set;
 
 public abstract class AbstractBitsquareModule extends AbstractModule {
 
     protected final Properties properties;
 
+    private final Set<AbstractBitsquareModule> modules = Sets.newHashSet();
+
     public AbstractBitsquareModule(Properties properties) {
         this.properties = properties;
     }
+
+    protected void install(AbstractBitsquareModule module) {
+        super.install(module);
+        modules.add(module);
+    }
+
+    /**
+     * Close any instances this module is responsible for and recursively close any
+     * sub-modules installed via {@link #install(AbstractBitsquareModule)}. This method
+     * must be called manually, e.g. at the end of a main() method or in the stop() method
+     * of a JavaFX Application; alternatively it may be registered as a JVM shutdown hook.
+     *
+     * @param injector the Injector originally initialized with this module
+     * @see #doClose(com.google.inject.Injector)
+     */
+    public final void close(Injector injector) {
+        modules.forEach(module -> module.close(injector));
+        doClose(injector);
+    }
+
+    /**
+     * Actually perform closing of any instances this module is responsible for. Called by
+     * {@link #close(Injector)}.
+     *
+     * @param injector the Injector originally initialized with this module
+     */
+    protected void doClose(Injector injector) {
+    }
 }

src/main/java/io/bitsquare/msg/DefaultMessageModule.java

@@ -19,6 +19,7 @@ package io.bitsquare.msg;
 
 import io.bitsquare.di.AbstractBitsquareModule;
 
+import com.google.inject.Injector;
 import com.google.inject.name.Names;
 
 import java.util.Properties;
@@ -43,4 +44,9 @@ public class DefaultMessageModule extends AbstractBitsquareModule implements Mes
                 .annotatedWith(Names.named("defaultSeedNode"))
                 .toInstance(SeedNodeAddress.StaticSeedNodeAddresses.DIGITAL_OCEAN1);
     }
+
+    @Override
+    public void doClose(Injector injector) {
+        injector.getInstance(MessageFacade.class).shutDown();
+    }
 }