java http post json

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mb63887cf57331d 2022-12-01 19:35:03

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.URL;

public class Copy_2_of_PostDemo {

  final static String url = "";
  final static String params = "{\"id\":\"12345\"}";

  /**
   * 发送HttpPost请求
   * 
   * @param strURL
   *            服务地址
   * @param params
   *            json字符串,例如: "{ \"id\":\"12345\" }" ;其中属性名必须带双引号<br/>
   * @return 成功:返回json字符串<br/>
   */
  public static String post(String strURL, String params) {
    System.out.println(strURL);
    System.out.println(params);
    try {
      URL url = new URL(strURL);// 创建连接
      HttpURLConnection connection = (HttpURLConnection) url
          .openConnection();
      connection.setDoOutput(true);
      connection.setDoInput(true);
      connection.setUseCaches(false);
      connection.setInstanceFollowRedirects(true);
      connection.setRequestMethod("POST"); // 设置请求方式
      connection.setRequestProperty("Accept", "application/json"); // 设置接收数据的格式
      connection.setRequestProperty("Content-Type", "application/json"); // 设置发送数据的格式
      connection.connect();
      OutputStreamWriter out = new OutputStreamWriter(
          connection.getOutputStream(), "UTF-8"); // utf-8编码
      out.append(params);
      out.flush();
      out.close();
      // 读取响应
      int length = (int) connection.getContentLength();// 获取长度
      InputStream is = connection.getInputStream();
      if (length != -1) {
        byte[] data = new byte[length];
        byte[] temp = new byte[512];
        int readLen = 0;
        int destPos = 0;
        while ((readLen = is.read(temp)) > 0) {
          System.arraycopy(temp, 0, data, destPos, readLen);
          destPos += readLen;
        }
        String result = new String(data, "UTF-8"); // utf-8编码
        System.out.println(result);
        return result;
      }
    } catch (IOException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }
    return "error"; // 自定义错误信息
  }

  public static void main(String[] args) {
    post(url, params);
  }

}