java使用线程池查询当前网段局域网ip

调用process类 进行ping

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.ArrayList;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

/**
 * ping测试
 * @author kernel 
 *
 */
public class PINGUtil {
    private final ArrayList<String> ping_res;
    public ArrayList<String> getResult(){
        return ping_res;
    }
    public  PINGUtil() throws UnknownHostException{
        ping_res=new ArrayList<String>();
        InetAddress inet=InetAddress.getLocalHost();
        String hostadress=inet.getHostAddress();
        System.out.println("hostadress:"+hostadress);
        int k=0;
        k=hostadress.lastIndexOf(".");
        String ping_sub=hostadress.substring(0,k+1);
        System.out.println("start execute");//获取网段
        ExecutorService exec=Executors.newFixedThreadPool(30);

        for(int i=1;i<=255;i++){     
             String pingip=ping_sub+i;
              exec.execute(new PingTread(pingip));
        } 
        System.out.println("run shutdown");
        exec.shutdown();//terminate shut 任务完成  就关闭线程
        System.out.println("asyc task：");
        try {
            System.out.println("awaitTermination task start");
            //堵塞time out 30s block 超时 直接跳过awaitTermination 但是exec会继续未完成的任务
            exec.awaitTermination(100000, TimeUnit.MILLISECONDS);
            System.out.println("awaitTermination task end");
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        System.out.println("end execute");

    }
    public class PingTread extends Thread{
        String ip;
        public PingTread(String ping_sub){
          this.ip=ping_sub; 
        }
        @Override
        public void run() {
            // TODO Auto-generated method stub
            super.run();
             InputStreamReader in=null;
             BufferedReader br=null;
                try {
                    /**
                     * Linux:ping [-dfnqrRv][-c<完成次数>][-i<间隔秒数>][-I<网络界面>][-l<前置载入>][-p<范本样式>][-s<数据包大小>][-t<存活数值>][主机名称或IP地址]
                     *  [ -d] [ -D ] [ -n ] [ -q ] [ -r] [ -v] [ \ -R ] [ -a addr_family ]
                     *  [ -c Count ] [ -w timeout ] [ -f | -i \ Wait ] 
                     *  [ -l Preload ] [ -p Pattern ] [ -s PacketSize ] 
                     *  [ -S hostname/IP addr ] \ [ -L ] [ - I a.b.c.d. ] 
                     *  [ -o interface ] [ -T ttl ] Host [ PacketSize ] \ [ Count ]
                     * 
                     * Windows: 
                     * ping [-t] [-a] [-n count] [-l size] [-f] [-i TTL] [-v TOS]
                     * [-r count] [-s count] [[-j host-list] | [-k host-list]]
                     * [-w timeout] target_name
                     * 
                     */
                    Process proces=Runtime.getRuntime().exec("cmd.exe /c ping "+ip+" -w 300 -n 1");//win /c 关闭          
                    //Process proces=Runtime.getRuntime().exec("/usr/bin/sh /c ping "+ip+" -w 300 -c 1");//linux /c 关闭              
                    //System.out.println("proces.hashCode() "+proces.hashCode());
                    in=new InputStreamReader(proces.getInputStream());
                    br=new BufferedReader(in);                  
                    StringBuffer sb=new StringBuffer();         
                    String buff;

                    while((buff=br.readLine())!=null){                  
                        sb.append(buff);                    
                    }   

                    if(sb.indexOf("timed out")==(-1)){
                        System.out.println(sb.toString());
                        //可以ping通的ip
                        ping_res.add(ip);
                    }
                    if(proces.waitFor()==0){
                        System.out.println("进程结束"); 
                    };


                } catch (IOException e) {
                    e.printStackTrace();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }finally{
                    if(br!=null){
                        try {
                            br.close();
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                    if(in!=null){
                        try {
                            in.close();
                        } catch (IOException e) {               
                            e.printStackTrace();
                        }
                    }

                }

        }

    }

    /**
     * @param args
     * 
     */
    public static void main(String[] args) throws UnknownHostException {
        PINGUtil pin= new PINGUtil();
        ArrayList<String> re=pin.getResult();
        for(String s:re){
            System.out.println("本地局域网："+s);
        }

    }

}

运行结果：

hostadress:192.168.2.103
start execute
run shutdown
asyc task：
awaitTermination task start
Pinging 192.168.2.1 with 32 bytes of data:Reply from 192.168.2.1: bytes=32 time=1ms TTL=64Ping statistics for 192.168.2.1:    Packets: Sent = 1, Received = 1, Lost = 0 (0% loss),Approximate round trip times in milli-seconds:    Minimum = 1ms, Maximum = 1ms, Average = 1ms
进程结束
Pinging 192.168.2.103 with 32 bytes of data:Reply from 192.168.2.103: bytes=32 time<1ms TTL=64Ping statistics for 192.168.2.103:    Packets: Sent = 1, Received = 1, Lost = 0 (0% loss),Approximate round trip times in milli-seconds:    Minimum = 0ms, Maximum = 0ms, Average = 0ms
进程结束
Pinging 192.168.2.102 with 32 bytes of data:Reply from 192.168.2.102: bytes=32 time=126ms TTL=64Ping statistics for 192.168.2.102:    Packets: Sent = 1, Received = 1, Lost = 0 (0% loss),Approximate round trip times in milli-seconds:    Minimum = 126ms, Maximum = 126ms, Average = 126ms
进程结束
Pinging 192.168.2.255 with 32 bytes of data:Reply from 192.168.2.1: bytes=32 time=6ms TTL=64Ping statistics for 192.168.2.255:    Packets: Sent = 1, Received = 1, Lost = 0 (0% loss),Approximate round trip times in milli-seconds:    Minimum = 6ms, Maximum = 6ms, Average = 6ms
进程结束
awaitTermination task end
end execute
本地局域网：192.168.2.1
本地局域网：192.168.2.103
本地局域网：192.168.2.102
本地局域网：192.168.2.255