added eager singleton scope for injection

scm-webapp/src/main/java/sonia/scm/EagerSingletonScopeModule.java

@@ -0,0 +1,203 @@
+/**
+ * Copyright (c) 2010, Sebastian Sdorra All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer. 2. Redistributions in
+ * binary form must reproduce the above copyright notice, this list of
+ * conditions and the following disclaimer in the documentation and/or other
+ * materials provided with the distribution. 3. Neither the name of SCM-Manager;
+ * nor the names of its contributors may be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * http://bitbucket.org/sdorra/scm-manager
+ *
+ */
+
+
+
+package sonia.scm;
+
+//~--- non-JDK imports --------------------------------------------------------
+
+import com.google.inject.AbstractModule;
+import com.google.inject.Binding;
+import com.google.inject.Inject;
+import com.google.inject.Injector;
+import com.google.inject.Key;
+import com.google.inject.Provider;
+import com.google.inject.Scope;
+import com.google.inject.Scopes;
+import com.google.inject.TypeLiteral;
+import com.google.inject.matcher.Matchers;
+import com.google.inject.spi.BindingScopingVisitor;
+import com.google.inject.spi.TypeEncounter;
+import com.google.inject.spi.TypeListener;
+
+//~--- JDK imports ------------------------------------------------------------
+
+import java.lang.annotation.Annotation;
+
+/**
+ *
+ * @author Sebastian Sdorra
+ */
+public class EagerSingletonScopeModule extends AbstractModule
+{
+
+  /** Field description */
+  private static EagerSingletonScope EAGERSINGLETON_SCOPE =
+    new EagerSingletonScope();
+
+  //~--- methods --------------------------------------------------------------
+
+  /**
+   * Method description
+   *
+   */
+  @Override
+  protected void configure()
+  {
+    bindScope(EagerSingleton.class, EAGERSINGLETON_SCOPE);
+
+    TypeListener listener = new EagerCreatingListener();
+
+    requestInjection(listener);
+    bindListener(Matchers.any(), listener);
+  }
+
+  //~--- inner classes --------------------------------------------------------
+
+  /**
+   * Class description
+   *
+   *
+   * @version        Enter version here..., 12/12/07
+   * @author         Enter your name here...
+   */
+  private static class EagerCreatingListener implements TypeListener
+  {
+
+    /**
+     * Method description
+     *
+     *
+     * @param type
+     * @param encounter
+     * @param <I>
+     */
+    @Override
+    public <I> void hear(TypeLiteral<I> type, TypeEncounter<I> encounter)
+    {
+      if (injector != null)
+      {
+        createIfEager(injector.getBinding(Key.get(type)));
+      }
+    }
+
+    /**
+     * Method description
+     *
+     *
+     * @param injector
+     */
+    @Inject
+    void injector(Injector injector)
+    {
+      this.injector = injector;
+
+      for (Binding<?> b : injector.getBindings().values())
+      {
+        createIfEager(b);
+      }
+    }
+
+    /**
+     * Method description
+     *
+     *
+     * @param b
+     */
+    private void createIfEager(final Binding<?> b)
+    {
+      b.acceptScopingVisitor(new BindingScopingVisitor<Void>()
+      {
+        @Override
+        public Void visitEagerSingleton()
+        {
+          return null;
+        }
+
+        @Override
+        public Void visitNoScoping()
+        {
+          return null;
+        }
+
+        @Override
+        public Void visitScope(Scope scope)
+        {
+          if (scope == EAGERSINGLETON_SCOPE)
+          {
+            b.getProvider().get();
+          }
+
+          return null;
+        }
+
+        @Override
+        public Void visitScopeAnnotation(
+          Class<? extends Annotation> scopeAnnotation)
+        {
+          return null;
+        }
+      });
+    }
+
+    //~--- fields -------------------------------------------------------------
+
+    /** Field description */
+    private Injector injector;
+  }
+
+
+  /**
+   * Class description
+   *
+   *
+   * @version        Enter version here..., 12/12/07
+   * @author         Enter your name here...
+   */
+  private static class EagerSingletonScope implements Scope
+  {
+
+    /**
+     * Method description
+     *
+     *
+     * @param key
+     * @param unscoped
+     * @param <T>
+     *
+     * @return
+     */
+    @Override
+    public <T> Provider<T> scope(Key<T> key, Provider<T> unscoped)
+    {
+      return Scopes.SINGLETON.scope(key, unscoped);
+    }
+  }
+}

scm-webapp/src/main/java/sonia/scm/ScmContextListener.java

@@ -186,6 +186,7 @@ public class ScmContextListener extends GuiceServletContextListener
 
     moduleList.add(new ScmInitializerModule());
     moduleList.add(new ScmSubscriberModule());
+    moduleList.add(new EagerSingletonScopeModule());
     moduleList.add(ShiroWebModule.guiceFilterModule());
     moduleList.add(main);
     moduleList.add(new ScmSecurityModule(servletContext));