java emulates Get and Post requests from http and sets the methods of ip and port proxies

This paper covers three basic points:

1. Because many companies have agents on their internal networks, the browser accesses the Internet through ip and port, and the java code simulates http get, which also requires an external network agent;

2. Java implements Get/Post request code of http;

3. Setting the attributes in the header of HttpURLConnection request

Cookie, ES20en-ES21en (browser type), and so on.

For example: add Header to the http request

conn.setRequestProperty("Authorization", authorization);

Note: I found 1 section of Get/Post simulation request code on the Internet, added the configuration of the agent, and the integration was completed.

package com.pasier.quanzi.web.controller;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.URL;
import java.net.URLConnection;
import java.util.List;
import java.util.Map;

public class HttpRequest {

  public static void main(String[] args) {
    //  If not set, as long as the proxy IP And the proxy port is correct , This option is not set 
    System.getProperties().setProperty("http.proxyHost", "10.22.40.32");
    System.getProperties().setProperty("http.proxyPort", "8080");
    //  Determines whether the agent was set up successfully 
    //  send  GET  request 
    System.out.println(sendGet(
        "http://www.baidu.com",
        "param1=xxx&param2=yyy"));
    //  send  POST  request 
  }

  /**
   *  To specify the URL send GET Method request 
   * 
   * @param url
   *       Sending a request URL
   * @param param
   *       Request parameter, the request parameter should be  name1=value1&name2=value2  In the form. 
   * @return URL  The response result of the remote resource that represents 
   */
  public static String sendGet(String url, String param) {
    String result = "";
    BufferedReader in = null;
    try {
      String urlNameString = url + "?" + param;
      URL realUrl = new URL(urlNameString);
      //  Open and URL The connection between 
      URLConnection connection = realUrl.openConnection();
      //  Sets the generic request properties 
      connection.setRequestProperty("accept", "*/*");
      connection.setRequestProperty("connection", "Keep-Alive");
      connection.setRequestProperty("user-agent",
          "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
      //  Establish the actual connection 
      connection.connect();
      //  Gets all response header fields 
      Map<String, List<String>> map = connection.getHeaderFields();
      //  Iterate through all the response header fields 
      for (String key : map.keySet()) {
        System.out.println(key + "--->" + map.get(key));
      }
      //  define  BufferedReader Input stream to read URL The response of the 
      in = new BufferedReader(new InputStreamReader(
          connection.getInputStream()));
      String line;
      while ((line = in.readLine()) != null) {
        result += line;
      }
    } catch (Exception e) {
      System.out.println(" send GET Request exception! " + e);
      e.printStackTrace();
    }
    //  use finally Block to close the input stream 
    finally {
      try {
        if (in != null) {
          in.close();
        }
      } catch (Exception e2) {
        e2.printStackTrace();
      }
    }
    return result;
  }

  /**
   *  To specify the  URL  send POST Method request 
   * 
   * @param url
   *       Sending a request  URL
   * @param param
   *       Request parameter, the request parameter should be  name1=value1&name2=value2  In the form. 
   * @return  The response result of the remote resource that represents 
   */
  public static String sendPost(String url, String param) {
    PrintWriter out = null;
    BufferedReader in = null;
    String result = "";
    try {
      URL realUrl = new URL(url);
      //  Open and URL The connection between 
      URLConnection conn = realUrl.openConnection();
      //  Sets the generic request properties 
      conn.setRequestProperty("accept", "*/*");
      conn.setRequestProperty("connection", "Keep-Alive");
      conn.setRequestProperty("user-agent",
          "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
      //  send POST The request must be set to the following two lines 
      conn.setDoOutput(true);
      conn.setDoInput(true);
      //  To obtain URLConnection Object corresponding output stream 
      out = new PrintWriter(conn.getOutputStream());
      //  Send request parameters 
      out.print(param);
      // flush Output stream buffering 
      out.flush();
      //  define BufferedReader Input stream to read URL The response of the 
      in = new BufferedReader(
          new InputStreamReader(conn.getInputStream()));
      String line;
      while ((line = in.readLine()) != null) {
        result += line;
      }
    } catch (Exception e) {
      System.out.println(" send  POST  Request exception! " + e);
      e.printStackTrace();
    }
    //  use finally Block to close the output stream, the input stream 
    finally {
      try {
        if (out != null) {
          out.close();
        }
        if (in != null) {
          in.close();
        }
      } catch (IOException ex) {
        ex.printStackTrace();
      }
    }
    return result;
  }
}