java模拟post请求发送json的例子

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;  }}

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;  }