core/src/com/google/inject/spi/InterceptorBinding.java

/**
 * Copyright (C) 2008 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.spi;

import com.google.inject.Binder;
import com.google.inject.internal.util.ImmutableList;
import static com.google.inject.internal.util.Preconditions.checkNotNull;
import com.google.inject.matcher.Matcher;
import java.lang.reflect.Method;
import java.util.List;
import org.aopalliance.intercept.MethodInterceptor;

/**
 * Registration of interceptors for matching methods of matching classes. Instances are created
 * explicitly in a module using {@link com.google.inject.Binder#bindInterceptor(
 * Matcher, Matcher, MethodInterceptor[]) bindInterceptor()} statements:
 * <pre>
 *     bindInterceptor(Matchers.subclassesOf(MyAction.class),
 *         Matchers.annotatedWith(Transactional.class),
 *         new MyTransactionInterceptor());</pre>
 *
 * or from an injectable type listener using {@link TypeEncounter#bindInterceptor(Matcher,
 * org.aopalliance.intercept.MethodInterceptor[]) TypeEncounter.bindInterceptor()}.
 *
 * @author jessewilson@google.com (Jesse Wilson)
 * @since 2.0
 */
public final class InterceptorBinding implements Element {
  private final Object source;
  private final Matcher<? super Class<?>> classMatcher;
  private final Matcher<? super Method> methodMatcher;
  private final ImmutableList<MethodInterceptor> interceptors;

  InterceptorBinding(
      Object source,
      Matcher<? super Class<?>> classMatcher,
      Matcher<? super Method> methodMatcher,
      MethodInterceptor[] interceptors) {
    this.source = checkNotNull(source, "source");
    this.classMatcher = checkNotNull(classMatcher, "classMatcher");
    this.methodMatcher = checkNotNull(methodMatcher, "methodMatcher");
    this.interceptors = ImmutableList.of(interceptors);
  }

  public Object getSource() {
    return source;
  }

  public Matcher<? super Class<?>> getClassMatcher() {
    return classMatcher;
  }

  public Matcher<? super Method> getMethodMatcher() {
    return methodMatcher;
  }

  public List<MethodInterceptor> getInterceptors() {
    return interceptors;
  }

  public <T> T acceptVisitor(ElementVisitor<T> visitor) {
    return visitor.visit(this);
  }

  public void applyTo(Binder binder) {
    binder.withSource(getSource()).bindInterceptor(classMatcher, methodMatcher,
        interceptors.toArray(new MethodInterceptor[interceptors.size()]));
  }
}