HttpClient发送Post请求

1、HttpClientUtil类，提供三个方法，分别是sendPostByForm，sendPostByJson，sendPostByXml

sendPostByForm 处理 application/x-www-form-urlencoded格式报文的请求

sendPostByJson  处理 application/json 格式报文的请求

sendPostByXml  处理 text/xml 格式报文的请求

package com.harara.fund.util.http;

import com.montnets.fund.constant.HttpConstant;
import com.montnets.fund.factory.LogFactory;
import com.montnets.fund.factory.service.LogService;
import org.apache.http.Header;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.message.BasicHeader;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

/**
 * @author : chenlinyan
 * @version : 2.0
 * @date : 2019/9/27 9:40
 */
public class HttpClientUtil {

    private static LogService logger = LogFactory.getLogger();
    /**
     * 通过post方式调用http接口
     * @param url     url路径
     * @param jsonParam    json格式的参数
     * @param reSend     重发次数
     * @return
     * @throws Exception
     */
    public static String sendPostByJson(String url, String jsonParam,int reSend) {
        //声明返回结果
        String result = "";
        //开始请求API接口时间
        long startTime=System.currentTimeMillis();
        //请求API接口的响应时间
        long endTime= 0L;
        HttpEntity httpEntity = null;
        HttpResponse httpResponse = null;
        HttpClient httpClient = null;
        try {
            // 创建连接
            httpClient = HttpClientFactory.getInstance().getHttpClient();
            // 设置请求头和报文
            HttpPost httpPost = HttpClientFactory.getInstance().httpPost(url);
            Header header=new BasicHeader("Accept-Encoding",null);
            httpPost.setHeader(header);
            // 设置报文和通讯格式
            StringEntity stringEntity = new StringEntity(jsonParam,HttpConstant.UTF8_ENCODE);
            stringEntity.setContentEncoding(HttpConstant.UTF8_ENCODE);
            stringEntity.setContentType(HttpConstant.APPLICATION_JSON);
            httpPost.setEntity(stringEntity);
            logger.info("请求{}接口的参数为{}",url,jsonParam);
            //执行发送，获取相应结果
            httpResponse = httpClient.execute(httpPost);
            httpEntity= httpResponse.getEntity();
            result = EntityUtils.toString(httpEntity);
        } catch (Exception e) {
            logger.error("请求{}接口出现异常",url,e);
            if (reSend > 0) {
                logger.info("请求{}出现异常:{}，进行重发。进行第{}次重发",url,e.getMessage(),(HttpConstant.REQ_TIMES-reSend +1));
                result = sendPostByJson(url, jsonParam, reSend - 1);
                if (result != null && !"".equals(result)) {
                    return result;
                }
            }
        }finally {
            try {
                EntityUtils.consume(httpEntity);
            } catch (IOException e) {
                logger.error("http请求释放资源异常",e);
            }
        }
        //请求接口的响应时间
        endTime=System.currentTimeMillis();
        logger.info("请求{}接口的响应报文内容为{},本次请求API接口的响应时间为:{}毫秒",url,result,(endTime-startTime));
        return result;

    }


    /**
     * 通过post方式调用http接口
     * @param url     url路径
     * @param map    json格式的参数
     * @param reSend     重发次数
     * @return
     * @throws Exception
     */
    public static String sendPostByForm(String url, Map<String,String> map,int reSend) {
        //声明返回结果
        String result = "";
        //开始请求API接口时间
        long startTime=System.currentTimeMillis();
        //请求API接口的响应时间
        long endTime= 0L;
        HttpEntity httpEntity = null;
        UrlEncodedFormEntity entity = null;
        HttpResponse httpResponse = null;
        HttpClient httpClient = null;
        try {
            // 创建连接
            httpClient = HttpClientFactory.getInstance().getHttpClient();
            // 设置请求头和报文
            HttpPost httpPost = HttpClientFactory.getInstance().httpPost(url);
            //设置参数
            List<NameValuePair> list = new ArrayList<NameValuePair>();
            Iterator iterator = map.entrySet().iterator();
            while(iterator.hasNext()){
                Map.Entry<String,String> elem = (Map.Entry<String, String>) iterator.next();
                list.add(new BasicNameValuePair(elem.getKey(),elem.getValue()));
            }
            entity = new UrlEncodedFormEntity(list,HttpConstant.UTF8_ENCODE);
            httpPost.setEntity(entity);
            logger.info("请求{}接口的参数为{}",url,map);
            //执行发送，获取相应结果
            httpResponse = httpClient.execute(httpPost);
            httpEntity= httpResponse.getEntity();
            result = EntityUtils.toString(httpEntity);
        } catch (Exception e) {
            logger.error("请求{}接口出现异常",url,e);
            if (reSend > 0) {
                logger.info("请求{}出现异常:{}，进行重发。进行第{}次重发",url,e.getMessage(),(HttpConstant.REQ_TIMES-reSend +1));
                result = sendPostByForm(url, map, reSend - 1);
                if (result != null && !"".equals(result)) {
                    return result;
                }
            }
        }finally {
            try {
                EntityUtils.consume(httpEntity);
            } catch (IOException e) {
                logger.error("http请求释放资源异常",e);
            }
        }
        //请求接口的响应时间
        endTime=System.currentTimeMillis();
        logger.info("请求{}接口的响应报文内容为{},本次请求API接口的响应时间为:{}毫秒",url,result,(endTime-startTime));
        return result;

    }
    /**
     * 通过post方式调用http接口
     * @param url     url路径
     * @param xmlParam    json格式的参数
     * @param reSend     重发次数
     * @return
     * @throws Exception
     */
    public static String sendPostByXml(String url, String xmlParam,int reSend) {
        //声明返回结果
        String result = "";
        //开始请求API接口时间
        long startTime = System.currentTimeMillis();
        //请求API接口的响应时间
        long endTime = 0L;
        HttpEntity httpEntity = null;
        HttpResponse httpResponse = null;
        HttpClient httpClient = null;
        try {
            // 创建连接
            httpClient = HttpClientFactory.getInstance().getHttpClient();
            // 设置请求头和报文
            HttpPost httpPost = HttpClientFactory.getInstance().httpPost(url);
            StringEntity stringEntity = new StringEntity(xmlParam, HttpConstant.UTF8_ENCODE);
            stringEntity.setContentEncoding(HttpConstant.UTF8_ENCODE);
            stringEntity.setContentType(HttpConstant.TEXT_XML);
            httpPost.setEntity(stringEntity);
            logger.info("请求{}接口的参数为{}", url, xmlParam);
            //执行发送，获取相应结果
            httpResponse = httpClient.execute(httpPost);
            httpEntity = httpResponse.getEntity();
            result = EntityUtils.toString(httpEntity,HttpConstant.UTF8_ENCODE);
        } catch (Exception e) {
            logger.error("请求{}接口出现异常", url, e);
            if (reSend > 0) {
                logger.info("请求{}出现异常:{}，进行重发。进行第{}次重发", url, e.getMessage(), (HttpConstant.REQ_TIMES - reSend + 1));
                result = sendPostByJson(url, xmlParam, reSend - 1);
                if (result != null && !"".equals(result)) {
                    return result;
                }
            }
        } finally {
            try {
                EntityUtils.consume(httpEntity);
            } catch (IOException e) {
                logger.error("http请求释放资源异常", e);
            }
            //请求接口的响应时间
            endTime = System.currentTimeMillis();
            logger.info("请求{}接口的响应报文内容为{},本次请求API接口的响应时间为:{}毫秒", url, result, (endTime - startTime));
            return result;
        }

    }
}

2、HttpClient工厂类HttpClientFactory，从工厂类获取HttpClient连接

package com.harara.fund.util.http;

import com.montnets.fund.constant.HttpConstant;
import org.apache.http.client.HttpClient;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.config.Registry;
import org.apache.http.config.RegistryBuilder;
import org.apache.http.conn.socket.ConnectionSocketFactory;
import org.apache.http.conn.socket.LayeredConnectionSocketFactory;
import org.apache.http.conn.socket.PlainConnectionSocketFactory;
import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;

import javax.net.ssl.SSLContext;
import java.security.NoSuchAlgorithmException;

/**
 * @author : harara
 * @version : 2.0
 * @date : 2019/9/27 10:12
 */
public class HttpClientFactory {


    private static HttpClientFactory instance = null;

    private HttpClientFactory()
    {
    }

    public synchronized static HttpClientFactory getInstance()
    {
        if (instance == null)
        {
            instance = new HttpClientFactory();
        }
        return instance;
    }


    public synchronized HttpClient getHttpClient()
    {
        HttpClient httpClient = null;
        if (HttpConstant.IS_KEEP_ALIVE)
        {
            //获取长连接
            httpClient = new KeepAliveHttpClientBuilder().getKeepAliveHttpClient();
        } else
        {
            // 获取短连接
            httpClient = new HttpClientBuilder().getHttpClient();
        }
        return httpClient;
    }

    public HttpPost httpPost(String httpUrl)
    {
        HttpPost httpPost = null;
        httpPost = new HttpPost(httpUrl);
        if (HttpConstant.IS_KEEP_ALIVE)
        {
            // 设置为长连接，服务端判断有此参数就不关闭连接。
            httpPost.setHeader("Connection", "Keep-Alive");
        }
        return httpPost;
    }



    private  static class  KeepAliveHttpClientBuilder{

        private  static HttpClient httpClient;

        /**
         * 获取http长连接
         */
        private synchronized HttpClient getKeepAliveHttpClient()
        {
            if (httpClient == null)
            {
                LayeredConnectionSocketFactory sslsf = null;
                try {
                    sslsf = new SSLConnectionSocketFactory(SSLContext.getDefault());
                } catch (NoSuchAlgorithmException e) {
                    e.printStackTrace();
                }

                Registry<ConnectionSocketFactory> socketFactoryRegistry = RegistryBuilder
                        .<ConnectionSocketFactory> create().register("https", sslsf)
                        .register("http", new PlainConnectionSocketFactory()).build();
                PoolingHttpClientConnectionManager cm = new PoolingHttpClientConnectionManager(socketFactoryRegistry);
                cm.setMaxTotal(HttpConstant.MAX_TOTAL);
                cm.setDefaultMaxPerRoute(HttpConstant.MAX_CONN_PER_ROUTE);

                RequestConfig requestConfig = RequestConfig.custom()
                        .setConnectTimeout(HttpConstant.CONNECT_TIMEOUT)
                        .setSocketTimeout(HttpConstant.SOCKET_TIMEOUT).build();
                // 创建连接
                httpClient =  HttpClients.custom().setDefaultRequestConfig(requestConfig).setConnectionManager(cm).build();
            }

            return httpClient;
        }
    }


    private  static class  HttpClientBuilder{
        private  HttpClient httpClient;
        /**
         * 获取http短连接
         */
        private synchronized HttpClient getHttpClient()
        {
            if(httpClient == null){
                RequestConfig requestConfig = RequestConfig.custom()
                        // 设置请求超时时间
                        .setConnectTimeout(HttpConstant.CONNECT_TIMEOUT)
                        // 设置响应超时时间
                        .setSocketTimeout(HttpConstant.SOCKET_TIMEOUT).build();
                // 创建连接
                httpClient = HttpClients.custom().setDefaultRequestConfig(requestConfig).build();
            }
            return httpClient;
        }
    }


}

3、HttpClient请求常量类

package com.harara.fund.constant;

/**
 * @author : harara
 * @version : 2.0
 * @date : 2019/9/27 9:39
 */
public class HttpConstant {

    /**httpClient连接超时时间,单位毫秒 */
    public static final int CONNECT_TIMEOUT = 3*1000;

    /**httpClient请求获取数据的超时时间(即响应时间) 单位毫秒*/
    public static final int SOCKET_TIMEOUT = 10*1000;

    /**http连接池大小*/
    public static final int MAX_TOTAL = 10;

    /**分配给同一个route(路由)最大的并发连接数*/
    public static final int MAX_CONN_PER_ROUTE = 2;

    /**http连接是否是长连接*/
    public static final boolean IS_KEEP_ALIVE = true;

    /**调用接口失败默认重新调用次数*/
    public static final int REQ_TIMES = 3;

    /**utf-8编码*/
    public static final String UTF8_ENCODE = "UTF-8";

    /** application/json */
    public static final String APPLICATION_JSON = "application/json";

    /** text/xml */
    public static final String TEXT_XML = "text/xml";

}

参考地址:https://blog.csdn.net/vipshop_fin_dev/article/details/80561976