org.devefx.httpmapper.spring.handler.HandlerExecutionChain.java Source code

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Here is the source code for org.devefx.httpmapper.spring.handler.HandlerExecutionChain.java

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/*
 * Copyright 2016-2017, Youqian Yue (devefx@163.com).
 *
 * 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.devefx.httpmapper.spring.handler;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import org.devefx.httpmapper.http.HandlerListener;
import org.devefx.httpmapper.http.RequestEntity;
import org.devefx.httpmapper.http.ResponseEntity;
import org.springframework.util.ObjectUtils;

public class HandlerExecutionChain {

    private HandlerListener[] listeners;

    private List<HandlerListener> listenerList;

    public void addListener(HandlerListener listener) {
        initListenerList().add(listener);
    }

    public void addListeners(HandlerListener... listeners) {
        if (!ObjectUtils.isEmpty(listeners)) {
            initListenerList().addAll(Arrays.asList(listeners));
        }
    }

    private List<HandlerListener> initListenerList() {
        if (this.listenerList == null) {
            this.listenerList = new ArrayList<HandlerListener>();
            if (this.listeners != null) {
                // An listener array specified through the constructor
                this.listenerList.addAll(Arrays.asList(this.listeners));
            }
        }
        this.listeners = null;
        return this.listenerList;
    }

    /**
     * Return the array of listeners to apply (in the given order).
     * @return the array of HandlerListeners instances (may be {@code null})
     */
    public HandlerListener[] getListeners() {
        if (this.listeners == null && this.listenerList != null) {
            this.listeners = this.listenerList.toArray(new HandlerListener[this.listenerList.size()]);
        }
        return this.listeners;
    }

    public void onRequest(RequestEntity requestEntity) throws Exception {
        HandlerListener[] listeners = getListeners();
        if (!ObjectUtils.isEmpty(listeners)) {
            for (HandlerListener listener : listeners) {
                listener.onRequest(requestEntity);
            }
        }
    }

    public void onResponse(RequestEntity requestEntity, ResponseEntity responseEntity) throws Exception {
        HandlerListener[] listeners = getListeners();
        if (!ObjectUtils.isEmpty(listeners)) {
            for (int i = listeners.length - 1; i >= 0; i--) {
                HandlerListener listener = listeners[i];
                listener.onResponse(requestEntity, responseEntity);
            }
        }
    }

}