Write post request in java (add post parameter)

网址和参数需要根据自己的情况修改

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.HttpURLConnection;
import java.net.URL;


public static String getHtmlByPost(String urlString) throws IOException{

/*
*  POST https://www.xxx.com
sign: 3149fa619b03988963bf1c53b8947f0e
Content-Type: application/x-www-form-urlencoded
Content-Length: 285
Host: www.xxx.com
Connection: Keep-Alive
Accept-Encoding: gzip
User-Agent: okhttp/3.2.0
_time=2017-12-15%2011%3A07%3A02&user_coordinate=116.307956%2C39.966622&coordinate=116.307956%2C39.966622&_osversion=6.0&radius=50000&_build=50&_platform=Android&_cityid=110100&_device=awiftb0%3A89%3A00%3A99%3A27%3Ae8&_version=3.8.3&page=1&channel=huijiachifan&size=10&_screen=1080x1810
*/
URL url = new URL(urlString);
//参数
StringBuilder parameterbulider = new StringBuilder();
//响应
StringBuilder responseBuilder = new StringBuilder();
BufferedReader reader = null;
PrintWriter out = null;

HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setInstanceFollowRedirects(false);
//post 请求必须设置此处
conn.setDoOutput(true);
conn.setDoInput(true);

conn.setUseCaches(false);
conn.setDefaultUseCaches(false);
conn.setConnectTimeout(30 * 1000);//连接超时
conn.setReadTimeout(30 * 1000);//读取超市
conn.setRequestMethod("POST");

//多个参数拼接
parameterbulider.append("sign=3149fa619b03988963bf1c53b8947f0e");
parameterbulider.append("Content-Type=application/x-www-form-urlencoded");
parameterbulider.append("Content-Length=285");
parameterbulider.append("Host=www.xxx.com");
parameterbulider.append("Connection=Keep-Alive");
parameterbulider.append("Accept-Encoding=gzip");
parameterbulider.append("User-Agent=okhttp/3.2.0");
parameterbulider.append("_time=2017-12-15%2011%3A07%3A02&user_coordinate=116.307956%2C39.966622&coordinate=116.307956%2C39.966622&_osversion=6.0&radius=50000&_build=50&_platform=Android&_cityid=110100&_device=awiftb0%3A89%3A00%3A99%3A27%3Ae8&_version=3.8.3&page=2&channel=huijiachifan&size=10&_screen=1080x1810");


out = new PrintWriter(conn.getOutputStream());
out.print(parameterbulider.toString());
out.flush();

reader = new BufferedReader(new InputStreamReader(conn.getInputStream(), "UTF-8"));
String line = null;
while ((line = reader.readLine()) != null)
{
  responseBuilder.append(line + "\n");
}
reader.close();
String result = responseBuilder.toString();
return result;
}
/**
测试*/
public static void main(String[] args) {
String url="https://www.xxx.com";
try {
System.out.println(getHtmlByPost(url));
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}