URLConnection分析

// url是一个http地址URL url = new URL("http://127.0.0.1:8080/index.jsp");URLConnection urlConnection = url.openConnection();HttpURLConnection httpURLConnection = (HttpURLConnection)urlConnection;// 底层的正在实现类System.out.println("httpURLConnection: " + httpURLConnection);// 真正获取获取链接httpURLConnection.connect();