com.lurencun.cfuture09.androidkit.http.async.RetryHandler.java Source code

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Here is the source code for com.lurencun.cfuture09.androidkit.http.async.RetryHandler.java

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/*
 * @(#)RetryHandler.java             Project:androidkit
 * Date:2013-5-8
 *
 * Copyright (c) 2013 CFuture09, Institute of Software, 
 * Guangdong Ocean University, Zhanjiang, GuangDong, China.
 * All rights reserved.
 *
 * 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.lurencun.cfuture09.androidkit.http.async;

import android.os.SystemClock;

import com.githang.androidkit.utils.Log4AK;

import org.apache.http.NoHttpResponseException;
import org.apache.http.client.HttpRequestRetryHandler;
import org.apache.http.client.methods.HttpUriRequest;
import org.apache.http.protocol.ExecutionContext;
import org.apache.http.protocol.HttpContext;

import java.io.IOException;
import java.io.InterruptedIOException;
import java.net.SocketException;
import java.net.UnknownHostException;
import java.util.HashSet;

import javax.net.ssl.SSLException;

/**
 * ??android-async-http??
 * 
 * @author Geek_Soledad <a target="_blank" href=
 *         "http://mail.qq.com/cgi-bin/qm_share?t=qm_mailme&email=XTAuOSVzPDM5LzI0OR0sLHM_MjA"
 *         style="text-decoration:none;"><img src=
 *         "http://rescdn.qqmail.com/zh_CN/htmledition/images/function/qm_open/ico_mailme_01.png"
 *         /></a>
 */
public class RetryHandler implements HttpRequestRetryHandler {
    private static final Log4AK log = Log4AK.getLog(RetryHandler.class);
    /**
     * ?
     */
    private static final int RETRY_SLEEP_TIME_MILLIS = 1500;
    /**
     * ????
     */
    private static HashSet<Class<?>> exceptionWhitelist = new HashSet<Class<?>>();
    /**
     * ?????
     */
    private static HashSet<Class<?>> exceptionBlacklist = new HashSet<Class<?>>();

    static {
        // ???
        exceptionWhitelist.add(NoHttpResponseException.class);
        // ??WI-FI3G
        exceptionWhitelist.add(UnknownHostException.class);
        // ??WI-FI3G
        exceptionWhitelist.add(SocketException.class);

        // ???
        exceptionBlacklist.add(InterruptedIOException.class);
        // SSL??????
        exceptionBlacklist.add(SSLException.class);
    }

    /**
     * 
     */
    private final int maxRetries;

    public RetryHandler(int maxRetries) {
        this.maxRetries = maxRetries;
    }

    @Override
    public boolean retryRequest(IOException exception, int executionCount, HttpContext context) {
        // ??
        boolean retry = true;

        // ?
        Boolean b = (Boolean) context.getAttribute(ExecutionContext.HTTP_REQ_SENT);
        boolean sent = (b != null && b.booleanValue());

        if (executionCount > maxRetries) {
            // ????
            retry = false;
        } else if (isInList(exceptionBlacklist, exception)) {
            // ??????
            retry = false;
        } else if (isInList(exceptionWhitelist, exception)) {
            // ????
            retry = true;
        } else if (!sent) {
            // ?????
            retry = true;
        }

        if (retry) {
            // resend all idempotent requests
            HttpUriRequest currentReq = (HttpUriRequest) context.getAttribute(ExecutionContext.HTTP_REQUEST);
            String requestType = currentReq.getMethod();
            retry = !requestType.equals("POST");
        }

        if (retry) {
            SystemClock.sleep(RETRY_SLEEP_TIME_MILLIS);
        } else {
            exception.printStackTrace();
            log.w(exception);
        }
        return retry;
    }

    protected boolean isInList(HashSet<Class<?>> list, Throwable tr) {
        for (Class<?> clazz : list) {
            if (clazz.isInstance(tr)) {
                return true;
            }
        }
        return false;
    }
}