/*
* Copyright 2008 biaoping.yin
*
* 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 org.frameworkset.web.servlet;
import java.util.ArrayList;
import java.util.List;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.log4j.Logger;
import org.frameworkset.util.CollectionUtils;
import org.frameworkset.util.ObjectUtils;
import org.frameworkset.web.servlet.handler.HandlerMeta;
/**
* <p>Title: HandlerExecutionChain.java</p>
* <p>Description: </p>
* <p>bboss workgroup</p>
* <p>Copyright (c) 2008</p>
* @Date 2010-9-23
* @author biaoping.yin
* @version 1.0
*/
public class HandlerExecutionChain {
private final HandlerMeta handler;
private static Logger logger = Logger.getLogger(HandlerExecutionChain.class);
private HandlerInterceptor[] interceptors;
private List<HandlerInterceptor> interceptorList;
private int interceptorIndex = -1;
/**
* Create a new HandlerExecutionChain.
* @param handler the handler object to execute
*/
public HandlerExecutionChain(HandlerMeta handler) {
this(handler, (HandlerInterceptor[])null);
}
/**
* Create a new HandlerExecutionChain.
* @param handler the handler object to execute
* @param interceptors the array of interceptors to apply
* (in the given order) before the handler itself executes
*/
public HandlerExecutionChain(Object handler, HandlerInterceptor... interceptors) {
if (handler instanceof HandlerExecutionChain) {
HandlerExecutionChain originalChain = (HandlerExecutionChain) handler;
this.handler = originalChain.getHandler();
this.interceptorList = new ArrayList<HandlerInterceptor>();
CollectionUtils.mergeArrayIntoCollection(originalChain.getInterceptors(), this.interceptorList);
CollectionUtils.mergeArrayIntoCollection(interceptors, this.interceptorList);
}
else {
this.handler = (HandlerMeta)handler;
this.interceptors = interceptors;
}
}
/**
* Return the handler object to execute.
* @return the handler object
*/
public HandlerMeta getHandler() {
return this.handler;
}
public void addInterceptor(HandlerInterceptor interceptor) {
initInterceptorList();
this.interceptorList.add(interceptor);
}
public void addInterceptors(HandlerInterceptor[] interceptors) {
if (interceptors != null) {
initInterceptorList();
for (int i = 0; i < interceptors.length; i++) {
this.interceptorList.add(interceptors[i]);
}
}
}
private void initInterceptorList() {
if (this.interceptorList == null) {
this.interceptorList = new ArrayList();
}
if (this.interceptors != null) {
for (int i = 0; i < this.interceptors.length; i++) {
this.interceptorList.add(this.interceptors[i]);
}
this.interceptors = null;
}
}
/**
* Return the array of interceptors to apply (in the given order).
* @return the array of HandlerInterceptors instances (may be <code>null</code>)
*/
public HandlerInterceptor[] getInterceptors() {
if (this.interceptors == null && this.interceptorList != null) {
this.interceptors = (HandlerInterceptor[])
this.interceptorList.toArray(new HandlerInterceptor[this.interceptorList.size()]);
}
return this.interceptors;
}
/**
* Delegates to the handler's <code>toString()</code>.
*/
public String toString() {
return String.valueOf(handler);
}
public void addInterceptors(
List<HandlerInterceptor> gloabelHandlerInterceptors)
{
this.initInterceptorList();
this.interceptorList.addAll(gloabelHandlerInterceptors);
}
/**
* Apply preHandle methods of registered interceptors.
* @return {@code true} if the execution chain should proceed with the
* next interceptor or the handler itself. Else, DispatcherServlet assumes
* that this interceptor has already dealt with the response itself.
*/
boolean applyPreHandle(HttpServletRequest request, HttpServletResponse response) throws Exception {
HandlerInterceptor[] interceptors = getInterceptors();
if (!ObjectUtils.isEmpty(interceptors)) {
for (int i = 0; i < interceptors.length; i++) {
HandlerInterceptor interceptor = interceptors[i];
if (!interceptor.preHandle(request, response, this.handler)) {
triggerAfterCompletion(request, response, null);
return false;
}
this.interceptorIndex = i;
}
}
return true;
}
/**
* Apply postHandle methods of registered interceptors.
*/
void applyPostHandle(HttpServletRequest request, HttpServletResponse response, ModelAndView mv) throws Exception {
HandlerInterceptor[] interceptors = getInterceptors();
if (!ObjectUtils.isEmpty(interceptors)) {
for (int i = interceptors.length - 1; i >= 0; i--) {
HandlerInterceptor interceptor = interceptors[i];
interceptor.postHandle(request, response, this.handler, mv);
}
}
}
/**
* Trigger afterCompletion callbacks on the mapped HandlerInterceptors.
* Will just invoke afterCompletion for all interceptors whose preHandle invocation
* has successfully completed and returned true.
*/
void triggerAfterCompletion(HttpServletRequest request, HttpServletResponse response, Exception ex)
throws Exception {
HandlerInterceptor[] interceptors = getInterceptors();
if (!ObjectUtils.isEmpty(interceptors)) {
for (int i = this.interceptorIndex; i >= 0; i--) {
HandlerInterceptor interceptor = interceptors[i];
try {
interceptor.afterCompletion(request, response, this.handler, ex);
}
catch (Throwable ex2) {
logger.error("HandlerInterceptor.afterCompletion threw exception", ex2);
}
}
}
}
/**
* Apply afterConcurrentHandlerStarted callback on mapped AsyncHandlerInterceptors.
*/
void applyAfterConcurrentHandlingStarted(HttpServletRequest request, HttpServletResponse response) {
HandlerInterceptor[] interceptors = getInterceptors();
if (!ObjectUtils.isEmpty(interceptors)) {
for (int i = interceptors.length - 1; i >= 0; i--) {
if (interceptors[i] instanceof AsyncHandlerInterceptor) {
try {
AsyncHandlerInterceptor asyncInterceptor = (AsyncHandlerInterceptor) interceptors[i];
asyncInterceptor.afterConcurrentHandlingStarted(request, response, this.handler);
}
catch (Throwable ex) {
logger.error("Interceptor [" + interceptors[i] + "] failed in afterConcurrentHandlingStarted", ex);
}
}
}
}
}
}