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。