Threading using isReachable () for XP for a subnet subnet

Question

I wrote an application that should do ping (use isReachable) for all clients on the subnet on which the host is located, but I get strange results when it runs on XP (SP2), it cannot get all the hosts. It seems to be associated with threading, as if I are inserting a connection and effectively forcing the application to use one thread that it runs on. It works fine on Windows 7 and on ubuntu linux without connecting, so I'm a little puzzled as to why it crashes on XP. It consisted of two classes that poorly publish them now. Also pretty new to java, so hopefully this will not become apparent. Thanks in advance.

Main.java

package subnetping;
import java.io.IOException;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.logging.Level;
import java.util.logging.Logger;

public class Main {
public static void main(String[] args) {
    //Set this to your ip and netmask
    Network myNetwork = new Network("192.168.1.33", 24);
   Thread t = null;
   for(String aHost : myNetwork.getClients()){
       t = new Thread(new pinger(aHost));
       t.start();

//           Following makes it work on XP by forcing wait on thread
//           try {
//               t.join();
//           } catch (InterruptedException ex) {
//               Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
//           }

   }
}
public static class pinger implements Runnable{
    private String host;
    private InetAddress address;
    public pinger(String host){
        this.host = host;
        try {
            address = InetAddress.getByName(host);
        } catch (UnknownHostException ex) {
            Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
        }
    }
    public void run(){
        try {
            if (address.isReachable(3000)) {
                System.out.println(host + " reachable");
            } 
        } catch (IOException ex) {
            Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
        }
    }
}
}

Network.java

package subnetping;

import java.util.ArrayList;
import java.util.List;

public class Network {
private String subnet = "";
private int subnetMask;
private List<String> myClients = new ArrayList<String>();

public Network(String hostIP, int subnetMask){
    this.subnetMask = subnetMask;
    this.subnet = getSubNet(hostIP, this.subnetMask);
    createClients();
}

private String ipToBinary(String ipNumber){
    String[] temp;
    String binOctet1;
    String binOctet2;
    String binOctet3;
    String binOctet4;
    String ipAsBinary;

    temp = ipNumber.split("\\.");
    binOctet1 = padLeftToEight(Integer.toBinaryString(Integer.parseInt(temp[0])));
    binOctet2 = padLeftToEight(Integer.toBinaryString(Integer.parseInt(temp[1])));
    binOctet3 = padLeftToEight(Integer.toBinaryString(Integer.parseInt(temp[2])));
    binOctet4 = padLeftToEight(Integer.toBinaryString(Integer.parseInt(temp[3])));
    ipAsBinary = binOctet1 + binOctet2 + binOctet3 + binOctet4;
    return ipAsBinary;
}

private String binaryToIP(String binaryIP){
    return longToIP(Long.parseLong(binaryIP, 2));
}

private Long ipToLong (String ipNumber){
    String[] temp;

    String binOctet1;
    String binOctet2;
    String binOctet3;
    String binOctet4;
    Long ipAsLong;

    temp = ipNumber.split("\\.");
    binOctet1 = padLeftToEight(Integer.toBinaryString(Integer.parseInt(temp[0])));
    binOctet2 = padLeftToEight(Integer.toBinaryString(Integer.parseInt(temp[1])));
    binOctet3 = padLeftToEight(Integer.toBinaryString(Integer.parseInt(temp[2])));
    binOctet4 = padLeftToEight(Integer.toBinaryString(Integer.parseInt(temp[3])));
    ipAsLong = Long.parseLong((binOctet1 + binOctet2 + binOctet3 + binOctet4),2);

    return ipAsLong;
}

private String longToIP (Long LongIP){
    String binOctet1;
    String binOctet2;
    String binOctet3;
    String binOctet4;
    int intOctet1;
    int intOctet2;
    int intOctet3;
    int intOctet4;
    String fullBin;
    String ipAsString;

    fullBin = padLeftToThirtyTwo(Long.toBinaryString(LongIP));

    binOctet1 = fullBin.substring(0, 8);
    binOctet2 = fullBin.substring(8, 16);
    binOctet3 = fullBin.substring(16, 24);
    binOctet4 = fullBin.substring(24);

    intOctet1 = Integer.parseInt(binOctet1, 2);
    intOctet2 = Integer.parseInt(binOctet2, 2);
    intOctet3 = Integer.parseInt(binOctet3, 2);
    intOctet4 = Integer.parseInt(binOctet4, 2);

    ipAsString = intOctet1 + "." + intOctet2 + "." + intOctet3 + "." + intOctet4;

    return ipAsString;
}

private String padLeftToEight(String octet){
    String paddedOctet = octet;
    if(octet.length() == 8){
        return octet;
    }else{
        for( int i = 1; i <= (8 - octet.length()); i++){
           paddedOctet = "0" + paddedOctet;
        }

        return paddedOctet;
    }
}

private String padLeftToThirtyTwo(String ipNumber){
    String paddedIPNumber = ipNumber;
    if(ipNumber.length() == 32){
        return ipNumber;
    }else{
        for( int i = 1; i <= (32 - ipNumber.length()); i++){
           paddedIPNumber = "0" + paddedIPNumber;
        }

        return paddedIPNumber;
    }
}

private String padRightToThirtyTwo(String ipNumber){
    String paddedIPNumber = ipNumber;
    if(ipNumber.length() == 32){
        return ipNumber;
    }else{
        for( int i = 1; i <= (32 - ipNumber.length()); i++){
           paddedIPNumber = paddedIPNumber + "0";
        }

        return paddedIPNumber;
    }
}

private String getSubNet(String ipNumber, int subnetMask){
    for(int i = 0; i < subnetMask; i++){
        subnet = subnet + ipToBinary(ipNumber).charAt(i);
    }
    return binaryToIP(padRightToThirtyTwo(subnet));
}

private void createClients(){
    long subnetLong;
    long clientRange;

    clientRange = ((long) Math.pow(2L, (32L - subnetMask)) - 2);
    subnetLong = ipToLong(this.subnet);

    for(int i = 1; i <= clientRange; i ++){
        myClients.add(longToIP(subnetLong + i));
    }

}

public List<String> getClients(){
    return myClients;
}
}

Answer 1

ping, . XP, isReachable() , ping. , , WMI, .

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