Java tutorial
/* * Copyright 2002-2018 the original author or authors. * * 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 * * https://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 org.springframework.aop.target; import java.io.Serializable; import org.springframework.aop.TargetSource; import org.springframework.util.Assert; import org.springframework.util.ObjectUtils; /** * Implementation of the {@link org.springframework.aop.TargetSource} interface * that holds a given object. This is the default implementation of the TargetSource * interface, as used by the Spring AOP framework. There is usually no need to * create objects of this class in application code. * * <p>This class is serializable. However, the actual serializability of a * SingletonTargetSource will depend on whether the target is serializable. * * @author Rod Johnson * @author Juergen Hoeller * @see org.springframework.aop.framework.AdvisedSupport#setTarget(Object) */ public class SingletonTargetSource implements TargetSource, Serializable { /** use serialVersionUID from Spring 1.2 for interoperability. */ private static final long serialVersionUID = 9031246629662423738L; /** Target cached and invoked using reflection. */ private final Object target; /** * Create a new SingletonTargetSource for the given target. * @param target the target object */ public SingletonTargetSource(Object target) { Assert.notNull(target, "Target object must not be null"); this.target = target; } @Override public Class<?> getTargetClass() { return this.target.getClass(); } @Override public Object getTarget() { return this.target; } @Override public void releaseTarget(Object target) { // nothing to do } @Override public boolean isStatic() { return true; } /** * Two invoker interceptors are equal if they have the same target or if the * targets or the targets are equal. */ @Override public boolean equals(Object other) { if (this == other) { return true; } if (!(other instanceof SingletonTargetSource)) { return false; } SingletonTargetSource otherTargetSource = (SingletonTargetSource) other; return this.target.equals(otherTargetSource.target); } /** * SingletonTargetSource uses the hash code of the target object. */ @Override public int hashCode() { return this.target.hashCode(); } @Override public String toString() { return "SingletonTargetSource for target object [" + ObjectUtils.identityToString(this.target) + "]"; } }