java判断ip是否能ping通

类似于ping命令

import java.io.*;

import java.net.*;

public class PseudoPing {

public static void main(String args[]) {

try {

Socket t = new Socket(args[0], 7);

DataInputStream dis = new DataInputStream(t.getInputStream());

PrintStream ps = new PrintStream(t.getOutputStream());

ps.println("Hello");

String str = dis.readLine();

if (str.equals("Hello"))

System.out.println("Alive!") ;

else

System.out.println("Dead or echo port not responding");

t.close();

} catch (IOException e) {

e.printStackTrace();

}

}

}

}

JDK1.5特性

import java.io.*;

import java.net.*;

public class ReachableTest {

public static void main(String args[]) {

try {

InetAddress address = InetAddress.getByName("web.mit.edu");

System.out.println("Name: " + address.getHostName());

System.out.println("Addr: " + address.getHostAddress());

System.out.println("Reach: " + address.isReachable(3000));

} catch (UnknownHostException e) {

System.err.println("Unable to lookup web.mit.edu");

} catch (IOException e) {

System.err.println("Unable to reach web.mit.edu");

}

}

}

isReachable（3000）用此方法测试是否可以达到该地址，返回值为true或者是false