com.google.gerrit.server.config.FactoryModule Maven / Gradle / Ivy
// Copyright (C) 2009 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package com.google.gerrit.server.config;
import com.google.inject.AbstractModule;
import com.google.inject.Key;
import com.google.inject.assistedinject.FactoryProvider;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
public abstract class FactoryModule extends AbstractModule {
/**
* Register an assisted injection factory.
*
* This function provides an automatic way to define a factory that creates a
* concrete type through assisted injection. For example to configure the
* following assisted injection case:
*
*
* public class Foo {
* public interface Factory {
* Foo create(int a);
* }
* @Inject
* Foo(Logger log, @Assisted int a) {...}
* }
*
*
* Just pass {@code Foo.Factory.class} to this method. The factory will be
* generated to return its one return type as declared in the creation method.
*
* @param
* @param factory interface which specifies the bean factory method.
*/
protected void factory(final Class factory) {
factory(Key.get(factory), factory);
}
/**
* Register an assisted injection factory.
*
* This function provides an automatic way to define a factory that creates a
* concrete type through assited injection. For example to configure the
* following assisted injection case:
*
*
* public class Foo {
* public interface Factory {
* Foo create(int a);
* }
* @Inject
* Foo(Logger log, @Assisted int a) {...}
* }
*
*
* Just pass {@code Foo.Factory.class} to this method. The factory will be
* generated to return its one return type as declared in the creation method.
*
* @param
* @param key key to bind with in Guice bindings.
* @param factory interface which specifies the bean factory method.
*/
protected void factory(final Key key, final Class factory) {
final Method[] methods = factory.getDeclaredMethods();
switch (methods.length) {
case 1: {
final Class result = methods[0].getReturnType();
if (isAbstract(result)) {
addError("Factory " + factory.getName() + " returns abstract result.");
} else {
bind(key).toProvider(FactoryProvider.newFactory(factory, result));
}
break;
}
case 0:
addError("Factory " + factory.getName() + " has no create method.");
break;
default:
addError("Factory " + factory.getName()
+ " has more than one create method.");
break;
}
}
private static boolean isAbstract(final Class result) {
return result.isInterface()
|| (result.getModifiers() & Modifier.ABSTRACT) == Modifier.ABSTRACT;
}
}