java使用代理模拟http get请求

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.InetSocketAddress;
import java.net.Proxy;
import java.net.URL;
import java.net.URLConnection;

public class Trans {
    static int timeout = 10 * 1000;// 以秒为单位
    static String host = "117.177.243.6";//117.177.243.7
    static int port = 80;

    /**
     * 主入口方法
     * @param args
     */
    public static void main(String[] args) {
        String url = "http://2018.ip138.com/ic.asp";
        String result = get(url);
        System.out.println(result);
    }
    
    /**
     * 向指定URL发送GET方法的请求
     */
    public static String get(String url) {
        String result = "";
        BufferedReader in = null;
        try {
            URL realUrl = new URL(url);
            
            // 创建代理服务器  
            InetSocketAddress addr = new InetSocketAddress(host, port);  
            Proxy proxy = new Proxy(Proxy.Type.HTTP, addr); //http 代理  
            
            // 打开和URL之间的连接
            URLConnection connection = realUrl.openConnection(proxy);
            
            // 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)");
            connection.setRequestProperty("Content-type", "application/x-www-form-urlencoded;");
            connection.setConnectTimeout(timeout);
            connection.setReadTimeout(timeout);

            // 建立实际的连接
            connection.connect();
            
            // 定义 BufferedReader输入流来读取URL的响应
            in = new BufferedReader(new InputStreamReader(connection.getInputStream(), "gbk"));
            String line;
            while ((line = in.readLine()) != null) {
                result += line;
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        finally {
            try {
                if (in != null) {
                    in.close();
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        return result;
    }
}