Properties prop = System.getProperties();

 prop.setProperty("http.proxyHost", "localhost");

 // 设置http访问要使用的代理服务器的端口

 prop.setProperty("http.proxyPort", "8118");

    Properties props = System.getProperties();

     props.setProperty("proxySet", "true");

     props.setProperty("http.proxyHost", "172.30.96.35");

     props.setProperty("http.proxyPort", "8080");

     props.setProperty("http.proxyUser", "uatxm990375");

     props.setProperty("http.proxyPassword", "Iccc2016");   

      URL url = new URL("http://www.baidu.com");

      InputStream in = url.openConnection().getInputStream();

      //方法二

      /*URL url = new URL("http://www.baidu.com");

      InputStream in = url.openStream();*/