Merge pull request #2 from segfly/master

Custom injectors support

README.md

@@ -130,6 +130,37 @@ This will work only for modules set to `modules()` bundle option.
 
 [Example](https://github.com/xvik/dropwizard-guicey/blob/master/src/test/groovy/ru/vyarus/dropwizard/guice/support/AutowiredModule.groovy)
 
+### Custom Injectors
+
+Some Guice extension libraries require Injectors created by their API.
+A custom Injector may be supplied by implementing `InjectorFactory` and passing an instance of this implementation to the bundle builder.
+For example, to add support for https://github.com/Netflix/governator one might create a factory like the following:
+
+```java
+public class GovernatorInjectorFactory implements InjectorFactory {
+    @Override
+    public Injector createInjector(Stage stage, Iterable<? extends Module> modules) {
+        return LifecycleInjector.builder().withModules(modules).build().createInjector();;
+    }
+}
+```
+
+and provide this factory when building the bundle for dropwizard:
+
+```java
+@Override
+void initialize(Bootstrap<TestConfiguration> bootstrap) {
+    bootstrap.addBundle(GuiceBundle.<TestConfiguration> builder()
+            .installers(ResourceInstaller.class, TaskInstaller.class, ManagedInstaller.class)
+            .extensions(MyTask.class, MyResource.class, MyManaged.class)
+            .modules(new MyModule())
+            .injectorFactory(new GovernatorInjectorFactory())
+            .build()
+    );
+    bootstrap.addCommand(new MyCommand())
+}
+```
+
 ### Extension ordering
 
 Some installers support extensions ordering (managed, lifecycle and admin servlet and filters).

gradle/config/pmd/pmd.xml

@@ -20,9 +20,9 @@
             <property name="minimum" value="30"/>
         </properties>
     </rule>
-    <rule ref="rulesets/java/codesize.xml/ExcessiveClassLength" message="Avoid classes longer than 200 lines">
+    <rule ref="rulesets/java/codesize.xml/ExcessiveClassLength" message="Avoid classes longer than 300 lines">
         <properties>
-            <property name="minimum" value="200"/>
+            <property name="minimum" value="300"/>
         </properties>
     </rule>
     <rule ref="rulesets/java/codesize.xml/TooManyMethods" message="Avoid classes longer than 25 methods">

src/main/java/ru/vyarus/dropwizard/guice/GuiceBundle.java

@@ -25,6 +25,8 @@
 import java.util.List;
 import java.util.Set;
 
+import ru.vyarus.dropwizard.guice.api.InjectorFactory;
+
 /**
  * Bundle enables guice integration for dropwizard. Guice context is configured in initialization phase,
  * but actual injector is created on run phase, This approach provides greater configuration options, because during
@@ -65,7 +67,8 @@
  */
 public final class GuiceBundle<T extends Configuration> implements ConfiguredBundle<T> {
 
-    private static Injector injector;
+    private static Injector       injector;
+    private InjectorFactory       injectorFactory  = new DefaultInjectorFactoryImpl();
 
     private final List<Module> modules = Lists.newArrayList();
     private final Set<String> autoscanPackages = Sets.newHashSet();
@@ -102,7 +105,7 @@ public void initialize(final Bootstrap bootstrap) {
     public void run(final T configuration, final Environment environment) throws Exception {
         modules.add(new GuiceSupportModule(scanner, installerConfig));
         configureModules(configuration, environment);
-        GuiceBundle.injector = Guice.createInjector(stage, modules);
+        GuiceBundle.injector = injectorFactory.createInjector(stage, modules);
         CommandSupport.initCommands(bootstrap.getCommands(), injector);
     }
 
@@ -150,6 +153,18 @@ public static <T extends Configuration> Builder<T> builder() {
     public static class Builder<T extends Configuration> {
         private final GuiceBundle<T> bundle = new GuiceBundle<T>();
 
+        /**
+         * Configures as custom {@link InjectorFactory}.
+         *
+         * @param injectorFactory
+         *            a custom factory for creating Guice injectors
+         * @return builder instance for chained calls
+         */
+        public Builder<T> injectorFactory(final InjectorFactory injectorFactory) {
+            bundle.injectorFactory = injectorFactory;
+            return this;
+        }
+
         /**
          * Enables auto scan feature.
          *
@@ -253,4 +268,17 @@ public GuiceBundle<T> build() {
             return build(Stage.PRODUCTION);
         }
     }
+
+    /**
+     * A default {@link InjectorFactory} that simply delegates to {@link Guice#createInjector(Stage, Module...)}.
+     *
+     * @author Nicholas Pace
+     * @since Dec 26, 2014
+     */
+    private class DefaultInjectorFactoryImpl implements InjectorFactory {
+        @Override
+        public Injector createInjector(final Stage stage, final Iterable<? extends Module> modules) {
+            return Guice.createInjector(stage, modules);
+        }
+    }
 }

src/main/java/ru/vyarus/dropwizard/guice/api/InjectorFactory.java

@@ -0,0 +1,26 @@
+package ru.vyarus.dropwizard.guice.api;
+
+import com.google.inject.Injector;
+import com.google.inject.Module;
+import com.google.inject.Stage;
+
+/**
+ * This interface may be implemented to provide custom Guice injectors and support certain types of Guice extension
+ * libraries.
+ *
+ * @author Nicholas Pace
+ * @since Dec 26, 2014
+ */
+public interface InjectorFactory {
+
+    /**
+     * Creates an injector instance.
+     * 
+     * @param stage
+     *            The stage for which the injector is created.
+     * @param modules
+     *            A list of modules for the injector.
+     * @return A new injector.
+     */
+    Injector createInjector(Stage stage, Iterable<? extends Module> modules);
+}

src/test/groovy/ru/vyarus/dropwizard/guice/unit/BundleTest.groovy

@@ -8,6 +8,8 @@ import io.dropwizard.setup.Bootstrap
 import io.dropwizard.setup.Environment
 import ru.vyarus.dropwizard.guice.AbstractTest
 import ru.vyarus.dropwizard.guice.GuiceBundle
+import ru.vyarus.dropwizard.guice.api.InjectorFactory;
+import com.google.inject.Injector;
 
 /**
  * @author Vyacheslav Rusakov 
@@ -30,6 +32,26 @@ class BundleTest extends AbstractTest {
         then: "injector available"
         true
     }
+
+    def "Check custom injector factory"() {
+        InjectorFactory mockInjectorFactory = Mock()
+        Injector mockInjector = Mock()
+
+        when: "using default factory"
+        GuiceBundle bundle = GuiceBundle.builder().build()
+        bundle.initialize(Mock(Bootstrap))
+        bundle.run(Mock(Configuration), mockEnvironment())        
+        then: "injector is a Guice injector"
+        GuiceBundle.getInjector() instanceof Injector
+
+        when: "using custom factory"        
+        bundle = GuiceBundle.builder().injectorFactory(mockInjectorFactory).build()
+        bundle.initialize(Mock(Bootstrap))
+        bundle.run(Mock(Configuration), mockEnvironment())
+        then: "injector factory has been customized"
+        1 * mockInjectorFactory.createInjector(_, _) >> mockInjector
+        GuiceBundle.getInjector() == mockInjector
+    }
 
     def "Check commands search" () {