java模拟http请求

java模拟http发送请求，第一种是HttpURLConnection发送post请求，第二种是使用httpclient模拟post请求，

方法一：

package main.utils;

import java.io.*;
import java.net.HttpURLConnection;
import java.net.URL;

public class HttpUtilTest {
    Log log = new Log(this.getClass());//初始化日志类
    /**
     * @作用 使用urlconnection
     * @param url
     * @param Params
     * @return
     * @throws IOException
     */
    public String sendPost(String url,String Params)throws IOException{
        OutputStreamWriter out = null;
        BufferedReader reader = null;
        String response="";
        try {
            URL httpUrl = null; //HTTP URL类 用这个类来创建连接
            //创建URL
            httpUrl = new URL(url);
            //建立连接
            HttpURLConnection conn = (HttpURLConnection) httpUrl.openConnection();
            conn.setRequestMethod("POST");
            conn.setRequestProperty("Content-Type", "application/json");
            conn.setRequestProperty("connection", "keep-alive");
            conn.setUseCaches(false);//设置不要缓存
            conn.setInstanceFollowRedirects(true);
            conn.setDoOutput(true);
            conn.setDoInput(true);
            conn.connect();
            //POST请求
            out = new OutputStreamWriter(
                    conn.getOutputStream());
            out.write(Params);
            out.flush();
            //读取响应
            reader = new BufferedReader(new InputStreamReader(
                    conn.getInputStream()));
            String lines;
            while ((lines = reader.readLine()) != null) {
                lines = new String(lines.getBytes(), "utf-8");
                response+=lines;
            }
            reader.close();
            // 断开连接
            conn.disconnect();

            log.info(response.toString());
        } catch (Exception e) {
        System.out.println("发送 POST 请求出现异常！"+e);
        e.printStackTrace();
        }
        //使用finally块来关闭输出流、输入流
        finally{
        try{
            if(out!=null){
                out.close();
            }
            if(reader!=null){
                reader.close();
            }
        }
        catch(IOException ex){
            ex.printStackTrace();
        }
    }

        return response;
    }
}

 

　方法二：使用httpclient实现

import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;

import main.utils.Log;

import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;

//post请求方法
public  String sendPost(String url, String data) {
   String response = null;
   log.info("url: " + url);
   log.info("request: " + data);
   try {
       CloseableHttpClient httpclient = null;
       CloseableHttpResponse httpresponse = null;
       try {
           httpclient = HttpClients.createDefault();
           HttpPost httppost = new HttpPost(url);
           StringEntity stringentity = new StringEntity(data,
                   ContentType.create("text/json", "UTF-8"));
           httppost.setEntity(stringentity);
           httpresponse = httpclient.execute(httppost);
           response = EntityUtils
                   .toString(httpresponse.getEntity());
           log.info("response: " + response);
       } finally {
           if (httpclient != null) {
               httpclient.close();
           }
           if (httpresponse != null) {
               httpresponse.close();
           }
       }
   } catch (Exception e) {
       e.printStackTrace();
   }
   return response;
}

 

 

附：httpClient 4.3中文手册，来自开源中国：https://my.oschina.net/u/565871/blog/701214