android 下测试网络的丢包率和延迟

String lost = new String();
            String delay = new String();
            Process p = Runtime.getRuntime().exec("ping -c 4 " + "119.147.15.13");
            BufferedReader buf = new BufferedReader(new InputStreamReader(p.getInputStream()));
            String str = new String();
            while((str=buf.readLine())!=null){
                if(str.contains("packet loss")){
                    int i= str.indexOf("received");
                    int j= str.indexOf("%");
                    System.out.println("丢包率:"+str.substring(i+10, j+1));
//                  System.out.println("丢包率:"+str.substring(j-3, j+1));
                    lost = str.substring(i+10, j+1);
                }
                if(str.contains("avg")){
                    int i=str.indexOf("/", 20);
                    int j=str.indexOf(".", i);
                    System.out.println("延迟:"+str.substring(i+1, j));
                    delay =str.substring(i+1, j);
                    delay = delay+"ms";
                }
 
            }