java判断网络连接是否正常

 1 /**
 2      * 判断本机当前的网络状态是否联通
 3      * 在这里主要用到中国天气信息，所以访问百度地址是否能够访问成功来判断当前的网络状态
 4      */
 5     public static boolean isConnect() {
 6         Runtime runtime = Runtime.getRuntime();
 7         try {
 8             Process process = runtime.exec("ping " + "www.baidu.com");
 9             InputStream is = process.getInputStream();
10             InputStreamReader isr = new InputStreamReader(is);
11             BufferedReader br = new BufferedReader(isr);
12             String line = null;
13             StringBuffer sb = new StringBuffer();
14             while ((line = br.readLine()) != null) {
15                 sb.append(line);
16             }
17             is.close();
18             isr.close();
19             br.close();
20  
21             if (null != sb && !sb.toString().equals("")) {
22                 if (sb.toString().indexOf("TTL") > 0) {
23                     //网络畅通
24                     return true;
25                 }
26             }
27         } catch (Exception e) {
28             e.printStackTrace();
29         }
30         
31         return false;
32     }