linux机器上执行ping命令的java方法

 

在编写网管系统的过程中，经常需要判断某台机器是否可用，于是采用使用ping机器的方法判断该机器当前是否可用，方法如下：

 

/**

 * @Title: execPingCommand

 * @Description: 执行ping命令，查看设备是否可用

 * @param @param deviceIp   

 * @return boolean  true-能ping通，false-不能ping通

 * @throws

 */

 public static boolean execPingCommand(String deviceIp){

  

  logger.debug("enter VolumeManage.execPingCommand(String deviceIp) ");

  

  boolean networkUseable = false;

  

  //String address="www.javawind.net"; 

            

        Process process = null;

  try {

   process = Runtime.getRuntime().exec("ping -c 3 "+deviceIp);

  } catch (IOException e1) {

   // TODO Auto-generated catch block

   logger.error("System error: ", e1);

  }

  

        InputStreamReader r = new InputStreamReader(process.getInputStream()); 

        LineNumberReader returnData = new LineNumberReader(r); 

 

        String returnMsg=""; 

        String line = "";

       

        try {

         

   while ((line = returnData.readLine()) != null) { 

        //System.out.println(line); 

        returnMsg += line;

               

   }

   

   if(returnMsg.indexOf("Unreachable") != -1 || returnMsg.indexOf("100% packet loss") != -1){ 

          networkUseable = false;

         } 

         else{ 

          networkUseable = true;

         } 

   

  }catch (IOException e) {

   // TODO Auto-generated catch block

   logger.error("System error: ", e);

  } finally{

   

   if(returnData != null){

    try {

     

     returnData.close();

     

    } catch (IOException e) {

     // TODO Auto-generated catch block

     logger.error("System error: ", e);

    }

   }

   

   if(r != null){

    try {

     r.close();

     

    } catch (IOException e) {

     // TODO Auto-generated catch block

     logger.error("System error: ", e);

    }

   }

   

  }

          

        logger.debug("exit VolumeManage.execPingCommand(String deviceIp) " + "[networkUseable] = " + networkUseable);

  return networkUseable;

 }

 

此方法关键命令为红色部分：ping -c 3 + ip;这个命令为linux系统所有，windows上不能执行，表示方法执行之后，只需要返回3行响应消息便可，不然在linux中，如果不终止该命令，会不停的打印响应的消息。

ping通机器的响应消息如下：

[root@abc ~]# ping -c 3 192.168.3.51

PING 192.168.3.51 (192.168.3.51) 56(84) bytes of data.

64 bytes from 192.168.3.51: icmp_seq=1 ttl=64 time=14.6 ms

64 bytes from 192.168.3.51: icmp_seq=2 ttl=64 time=0.332 ms

64 bytes from 192.168.3.51: icmp_seq=3 ttl=64 time=0.359 ms

--- 192.168.3.51 ping statistics ---

3 packets transmitted, 3 received, 0% packet loss, time 2000ms

rtt min/avg/max/mdev = 0.332/5.103/14.619/6.728 ms

[root@abc ~]#

 

ping不同的机器的响应消息如下：

[root@abc ~]# ping -c 3 192.168.3.52

PING 192.168.3.52 (192.168.3.52) 56(84) bytes of data.

From 192.168.7.181 icmp_seq=1 Destination Host Unreachable

From 192.168.7.181 icmp_seq=2 Destination Host Unreachable

From 192.168.7.181 icmp_seq=3 Destination Host Unreachable

--- 192.168.3.52 ping statistics ---

3 packets transmitted, 0 received, +3 errors, 100% packet loss, time 2000ms

, pipe 3

[root@abc ~]#

 

因此，方法根据这两个条件进行判断，如果含有Unreachable或者100% packet loss就表示机器ping不同，不可用，否则为可用。