interceptorschain.java

一个非常好的FRAMWRK!是一个外国组织做的!不!

/*
 * Copyright 2003-2005 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
 *
 * 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.jdon.aop.interceptor;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.aopalliance.intercept.MethodInterceptor;

import com.jdon.aop.joinpoint.Pointcut;
import com.jdon.container.pico.Startable;
import com.jdon.util.Debug;


/**
 * Interceptors chain
 * 
 * all interceptors will add in this collection
 * 
 * @author <a href="mailto:[e-mail]">banq</a>
 *
 */
public class InterceptorsChain implements Startable{
    private final static String module = InterceptorsChain.class.getName();
    public final static String NAME = "InterceptorsChain";
    
    /**
     * the key is interceptor target
     * the value is the interceptor instance
     */
    private Map chain = new HashMap();
    
    public void start(){
        Debug.logVerbose("InterceptorsChain start..", module);
    }
    
    public void stop(){
        chain.clear();
    }
  
    public void addInterceptor(String pointcut, MethodInterceptor interceptor ){
        List interceptors = getInterceptors(pointcut);
        if ((interceptors == null) && isPointcut(pointcut)){
            interceptors = new ArrayList();
            chain.put(pointcut, interceptors);
        }
        interceptors.add(interceptor);
    }
    
    private boolean isPointcut(String pointcut){
        if ((pointcut.equals(Pointcut.TARGET_PROPS_SERVICES)) ||
            (pointcut.equals(Pointcut.EJB_TARGET_PROPS_SERVICES)) ||
            (pointcut.equals(Pointcut.POJO_TARGET_PROPS_SERVICES)))
            return true;
        else 
            return false;            
    }
    
    
    /**
     * @return Returns the interceptors.
     */
    public List getInterceptors(String pointcut) {
        return (List)chain.get(pointcut);
    }
    
    public int size(){
        return chain.size();
    }
}