Java implements HTTP Post Get and proxy access requests

This article illustrates the Java implementation of HTTP Post, Get, proxy access requests detailed code fragments, Shared for your reference, the specific content is as follows

package com.snowfigure.kits.net;
 
import java.io.BufferedReader; 
import java.io.IOException;
import java.io.InputStream; 
import java.io.InputStreamReader; 
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException; 
import java.net.HttpURLConnection; 
import java.net.InetSocketAddress;
import java.net.Proxy;
import java.net.URL; 
import java.net.URLConnection;
import java.util.List;
import java.util.Map;
 

public class HttpRequestUtil {
  static boolean proxySet = false;
  static String proxyHost = "127.0.0.1";
  static int proxyPort = 8087;
   
  public static String urlEncode(String source,String encode) { 
    String result = source; 
    try { 
      result = java.net.URLEncoder.encode(source,encode); 
    } catch (UnsupportedEncodingException e) { 
      e.printStackTrace(); 
      return "0"; 
    } 
    return result; 
  }
  public static String urlEncodeGBK(String source) { 
    String result = source; 
    try { 
      result = java.net.URLEncoder.encode(source,"GBK"); 
    } catch (UnsupportedEncodingException e) { 
      e.printStackTrace(); 
      return "0"; 
    } 
    return result; 
  }
   
  public static String httpRequest(String req_url) {
    StringBuffer buffer = new StringBuffer(); 
    try { 
      URL url = new URL(req_url); 
      HttpURLConnection httpUrlConn = (HttpURLConnection) url.openConnection(); 
  
      httpUrlConn.setDoOutput(false); 
      httpUrlConn.setDoInput(true); 
      httpUrlConn.setUseCaches(false); 
  
      httpUrlConn.setRequestMethod("GET"); 
      httpUrlConn.connect(); 
  
      //Replace the returned input stream with a string
      InputStream inputStream = httpUrlConn.getInputStream(); 
      InputStreamReader inputStreamReader = new InputStreamReader(inputStream, "utf-8"); 
      BufferedReader bufferedReader = new BufferedReader(inputStreamReader); 
  
      String str = null; 
      while ((str = bufferedReader.readLine()) != null) { 
        buffer.append(str); 
      } 
      bufferedReader.close(); 
      inputStreamReader.close(); 
      //Release resources
      inputStream.close(); 
      inputStream = null; 
      httpUrlConn.disconnect(); 
  
    } catch (Exception e) { 
      System.out.println(e.getStackTrace()); 
    } 
    return buffer.toString(); 
  } 
    
   
  public static InputStream httpRequestIO(String requestUrl) { 
    InputStream inputStream = null; 
    try { 
      URL url = new URL(requestUrl); 
      HttpURLConnection httpUrlConn = (HttpURLConnection) url.openConnection(); 
      httpUrlConn.setDoInput(true); 
      httpUrlConn.setRequestMethod("GET"); 
      httpUrlConn.connect(); 
      //Gets the returned input stream
      inputStream = httpUrlConn.getInputStream(); 
    } catch (Exception e) { 
      e.printStackTrace(); 
    } 
    return inputStream; 
  }
   
   
  
  public static String sendGet(String url, String param) {
    String result = "";
    BufferedReader in = null;
    try {
      String urlNameString = url + "?" + param;
      URL realUrl = new URL(urlNameString);
      //Open the connection between and URL
      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 the response header fields
      Map<String, List<String>> map = connection.getHeaderFields();
      //Traverses all response header fields
      for (String key : map.keySet()) {
        System.out.println(key + "--->" + map.get(key));
      }
      //Define a BufferedReader input stream to read the response to the URL
      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 a finally block to close the input stream
    finally {
      try {
        if (in != null) {
          in.close();
        }
      } catch (Exception e2) {
        e2.printStackTrace();
      }
    }
    return result;
  }
 
  
  public static String sendPost(String url, String param,boolean isproxy) {
    OutputStreamWriter out = null;
    BufferedReader in = null;
    String result = "";
    try {
      URL realUrl = new URL(url);
      HttpURLConnection conn = null;
      if(isproxy){//Using the proxy pattern
        @SuppressWarnings("static-access")
        Proxy proxy = new Proxy(Proxy.Type.DIRECT.HTTP, new InetSocketAddress(proxyHost, proxyPort));
        conn = (HttpURLConnection) realUrl.openConnection(proxy);
      }else{
        conn = (HttpURLConnection) realUrl.openConnection();
      }
      //Open the connection between and URL
       
      //The following two lines must be set to send the POST request
      conn.setDoOutput(true);
      conn.setDoInput(true);
      conn.setRequestMethod("POST");  //POST method
       
       
      //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)");
      conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
       
      conn.connect();
       
      //Gets the output stream corresponding to the URLConnection object
      out = new OutputStreamWriter(conn.getOutputStream(), "UTF-8");
      //Send request parameters
      out.write(param);
      //Flush the buffer of the output stream
      out.flush();
      //Define a BufferedReader input stream to read the response to the URL
      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 a 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;
  }  
   
  public static void main(String[] args) {
    //Demo: proxy access
    String url = "http://api.adf.ly/api.php";
    String para = "key=youkeyid&youuid=uid&advert_type=int&domain=adf.ly&url=http://somewebsite.com";
     
    String sr=HttpRequestUtil.sendPost(url,para,true);
    System.out.println(sr);
  }
   
}

I hope this article has helped you learn Java programming.