异步Http请求封装工具类AsyncHttpClientUtil

这里有两种封装，分别是：

    1：建立异步Http请求客户端之后，所有http请求都复用该HttpAsyncClient，内部只对应一个Reactor I/O线程。

请求的回调函数中不关闭HttpAsyncClient。

    2：每次请求都建立一个新的HttpAsyncClient，请求回调结束后关闭HttpAsyncClient，释放资源。

在我的项目中，我选择第一种：复用单例HttpAsyncClient，因为一个Reactor I/O线程其实可以

同时处理成千上万个连接请求，完全满足我的项目需要。

 

一、单例HttpAsyncClient

package com.peas.pay.util;

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.methods.HttpUriRequest;
import org.apache.http.concurrent.FutureCallback;
import org.apache.http.impl.nio.client.CloseableHttpAsyncClient;
import org.apache.http.impl.nio.client.HttpAsyncClients;
import org.apache.http.impl.nio.reactor.IOReactorConfig;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;

import com.google.common.base.Preconditions;
import com.google.common.collect.Lists;

import lombok.extern.log4j.Log4j;

/**
 * Created by xiekunliang on 2018/3/24. 异步Http请求封装工具类
 */
@Log4j
public class AsyncHttpClientUtil
{
    private static CloseableHttpAsyncClient httpClient;
    private static volatile boolean isClientStart;

    /**
     * 创建CloseableHttpAsyncClient
     * @return
     */
    private static CloseableHttpAsyncClient createCustomAsyncClient()
    {
        Preconditions.checkState(!isClientStart, "客户端HttpAsyncClient已经建立过了");
        IOReactorConfig ioReactorConfig = IOReactorConfig.custom()
                .setIoThreadCount(Runtime.getRuntime().availableProcessors())
                .setConnectTimeout(60000)
                .setSoTimeout(60000)
                .build();
        // 设置超时时间 毫秒为单位
        RequestConfig requestConfig = RequestConfig
                .copy(RequestConfig.DEFAULT)
                .setConnectTimeout(60000)
                .build();
        return HttpAsyncClients
                .custom()
                .setDefaultIOReactorConfig(ioReactorConfig)
                .setDefaultRequestConfig(requestConfig)
                .build();

    }


    public static void startHttpClient()
    {
        httpClient = createCustomAsyncClient();