java实现http的Post、Get、代理访问请求

本文实例讲解了java实现http的Post、Get、代理访问请求的详细代码片段，分享给大家供大家参考，具体内容如下

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;

/**
 * Http请求工具类
 * @author snowfigure
 * @since 2014-8-24 13:30:56
 * @version v1.0.1
 */
public class HttpRequestUtil {
  static boolean proxySet = false;
  static String proxyHost = "127.0.0.1";
  static int proxyPort = 8087;
  /**
   * 编码
   * @param source
   * @return
   */
  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;
  }
  /**
   * 发起http请求获取返回结果
   * @param req_url 请求地址
   * @return
   */
  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();

      // 将返回的输入流转换成字符串
      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();
      // 释放资源
      inputStream.close();
      inputStream = null;
      httpUrlConn.disconnect();

    } catch (Exception e) {
      System.out.println(e.getStackTrace());
    }
    return buffer.toString();
  }

  /**
   * 发送http请求取得返回的输入流
   * @param requestUrl 请求地址
   * @return InputStream
   */
  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();
      // 获得返回的输入流
      inputStream = httpUrlConn.getInputStream();
    } catch (Exception e) {
      e.printStackTrace();
    }
    return inputStream;
  }


  /**
   * 向指定URL发送GET方法的请求
   *
   * @param url
   *      发送请求的URL
   * @param param
   *      请求参数，请求参数应该是 name1=value1&name2=value2 的形式。
   * @return URL 所代表远程资源的响应结果
   */
  public static String sendGet(String url, String param) {
    String result = "";
    BufferedReader in = null;
    try {
      String urlNameString = url + "?" + param;
      URL realUrl = new URL(urlNameString);
      // 打开和URL之间的连接
      URLConnection connection = realUrl.openConnection();
      // 设置通用的请求属性
      connection.setRequestProperty("accept", "*/*");
      connection.setRequestProperty("connection", "Keep-Alive");
      connection.setRequestProperty("user-agent",
          "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
      // 建立实际的连接
      connection.connect();
      // 获取所有响应头字段
      Map<String, List<String>> map = connection.getHeaderFields();
      // 遍历所有的响应头字段
      for (String key : map.keySet()) {
        System.out.println(key + "--->" + map.get(key));
      }
      // 定义 BufferedReader输入流来读取URL的响应
      in = new BufferedReader(new InputStreamReader(
          connection.getInputStream()));
      String line;
      while ((line = in.readLine()) != null) {
        result += line;
      }
    } catch (Exception e) {
      System.out.println("发送GET请求出现异常！" + e);
      e.printStackTrace();
    }
    // 使用finally块来关闭输入流
    finally {
      try {
        if (in != null) {
          in.close();
        }
      } catch (Exception e2) {
        e2.printStackTrace();
      }
    }
    return result;
  }

  /**
   * 向指定 URL 发送POST方法的请求
   *
   * @param url
   *      发送请求的 URL
   * @param param
   *      请求参数，请求参数应该是 name1=value1&name2=value2 的形式。
   * @param isproxy
   *        是否使用代理模式
   * @return 所代表远程资源的响应结果
   */
  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){//使用代理模式
        @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();
      }
      // 打开和URL之间的连接

      // 发送POST请求必须设置如下两行
      conn.setDoOutput(true);
      conn.setDoInput(true);
      conn.setRequestMethod("POST");  // POST方法


      // 设置通用的请求属性

      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();

      // 获取URLConnection对象对应的输出流
      out = new OutputStreamWriter(conn.getOutputStream(), "UTF-8");
      // 发送请求参数
      out.write(param);
      // flush输出流的缓冲
      out.flush();
      // 定义BufferedReader输入流来读取URL的响应
      in = new BufferedReader(
          new InputStreamReader(conn.getInputStream()));
      String line;
      while ((line = in.readLine()) != null) {
        result += line;
      }
    } 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(in!=null){
          in.close();
        }
      }
      catch(IOException ex){
        ex.printStackTrace();
      }
    }
    return result;
  }

  public static void main(String[] args) {
    //demo:代理访问
    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);
  }

}

希望本文所述对大家学习java程序设计有所帮助。