circulardependencytest.java

Guice是轻量级的依赖注入框架。简而言之

/**
 * Copyright (C) 2006 Google Inc.
 *
 * 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.inject;

import junit.framework.TestCase;

/**
 * @author [e-mail] (Bob Lee)
 */
public class CircularDependencyTest extends TestCase {

  public void testCircularlyDependentConstructors()
      throws CreationException {
    BinderImpl builder = new BinderImpl();
    builder.bind(A.class).to(AImpl.class);
    builder.bind(B.class).to(BImpl.class);

    Injector injector = builder.createInjector();
    A a = injector.getInstance(A.class);
    assertNotNull(a.getB().getA());
  }

  interface A {
    B getB();
  }

  @Singleton
  static class AImpl implements A {
    final B b;
    @Inject public AImpl(B b) {
      this.b = b;
    }
    public B getB() {
      return b;
    }
  }

  interface B {
    A getA();
  }

  static class BImpl implements B {
    final A a;
    @Inject public BImpl(A a) {
      this.a = a;
    }
    public A getA() {
      return a;
    }
  }

}