Login into a remote host and test one ip whether its pinging or not.

Question

Hello Friends
I need to login into a remote host. From that remote host i need to test one ip that whether its is pinging or not.
For that i have written one code snippet its working fine when that ip is pinging.
But it is hanging when that ip is not pinging properly.
I could not read the output while not pinging.
For making telnet connection to the remote host, i am using jcsh.jar
Any body know the solution for that please help me.see below my code.
/* -*-mode:java; c-basic-offset:2; indent-tabs-mode:nil -*- */
import com.jcraft.jsch.*;
import java.awt.*;
import javax.swing.*;
import java.io.*;
public class Exec{
  public static void main(String[] arg){
    try{
      JSch jsch=new JSch(); 
      String temp = "";
      String host=null;
      if(arg.length>0){
        host=arg[0];
      else{
        host=JOptionPane.showInputDialog("Enter username@hostname",System.getProperty("user.name")+"@localhost");
      String user=host.substring(0, host.indexOf('@'));
      host=host.substring(host.indexOf('@')+1);
      Session session=jsch.getSession(user, host, 22);
      // username and password will be given via UserInfo interface.
      UserInfo ui=new MyUserInfo();
      session.setUserInfo(ui);
      session.connect();
      String command=JOptionPane.showInputDialog("Enter command",
                                                 "ping ");
      Channel channel=session.openChannel("exec");
      ((ChannelExec)channel).setCommand(command);
      channel.setInputStream(null);
      ((ChannelExec)channel).setErrStream(System.err);
      BufferedWriter stdOut = new BufferedWriter(new OutputStreamWriter(channel.getOutputStream()));
      channel.connect();
      int count = 0;
      int count1 = 0;
      while(true) {
      if((temp = stdInput.readLine()) != null || (temp = stdInput.readLine()).compareTo("") != 0 ) {
           System.out.println("NOT NULL OUTPUT");
           while ((temp = stdInput.readLine()) != null) {
           System.out.println(">"+temp);
            if(temp.indexOf("64 bytes from") == 0) {
               if(count++ > 4)
                    System.out.println("Ping Okay");
                    channel.disconnect();
                    break;
        try{Thread.sleep(1000);}catch(Exception ee){}
      else
           System.out.println(">"+temp);
           count1++;
           if(count1>10)
                System.out.println("Ping is not okay.");
                break;
           else {
                System.out.println("Trying...");
//                continue;
           try{Thread.sleep(1000);}catch(Exception ee){}
      if(channel.isClosed()){
          System.out.println("exit-status: "+channel.getExitStatus());
          break;
      channel.disconnect();
      session.disconnect();
    catch(Exception e){
      System.out.println(e);
  public static class MyUserInfo implements UserInfo, UIKeyboardInteractive{
    public String getPassword(){ return passwd; }
    public boolean promptYesNo(String str){
      Object[] options={ "yes", "no" };
      int foo=JOptionPane.showOptionDialog(null,
             str,
             "Warning",
             JOptionPane.DEFAULT_OPTION,
             JOptionPane.WARNING_MESSAGE,
             null, options, options[0]);
       return foo==0;
    String passwd;
    JTextField passwordField=(JTextField)new JPasswordField(20);
    public String getPassphrase(){ return null; }
    public boolean promptPassphrase(String message){ return true; }
    public boolean promptPassword(String message){
      Object[] ob={passwordField};
      int result=
        JOptionPane.showConfirmDialog(null, ob, message,
                                      JOptionPane.OK_CANCEL_OPTION);
      if(result==JOptionPane.OK_OPTION){
         passwd=passwordField.getText();
        return true;
      else{
        return false;
    public void showMessage(String message){
      JOptionPane.showMessageDialog(null, message);
    final GridBagConstraints gbc =
      new GridBagConstraints(0,0,1,1,1,1,
                             GridBagConstraints.NORTHWEST,
                             GridBagConstraints.NONE,
                             new Insets(0,0,0,0),0,0);
    private Container panel;
    public String[] promptKeyboardInteractive(String destination,
                                              String name,
                                              String instruction,
                                              String[] prompt,
                                              boolean[] echo){
      panel = new JPanel();
      panel.setLayout(new GridBagLayout());
      gbc.weightx = 1.0;
      gbc.gridwidth = GridBagConstraints.REMAINDER;
      gbc.gridx = 0;
      panel.add(new JLabel(instruction), gbc);
      gbc.gridy++;
      gbc.gridwidth = GridBagConstraints.RELATIVE;
      JTextField[] texts=new JTextField[prompt.length];
      for(int i=0; i<prompt.length; i++){
        gbc.fill = GridBagConstraints.NONE;
        gbc.gridx = 0;
        gbc.weightx = 1;
        panel.add(new JLabel(prompt),gbc);
gbc.gridx = 1;
gbc.fill = GridBagConstraints.HORIZONTAL;
gbc.weighty = 1;
if(echo[i]){
texts[i]=new JTextField(20);
else{
texts[i]=new JPasswordField(20);
panel.add(texts[i], gbc);
gbc.gridy++;
if(JOptionPane.showConfirmDialog(null, panel,
destination+": "+name,
JOptionPane.OK_CANCEL_OPTION,
JOptionPane.QUESTION_MESSAGE)
==JOptionPane.OK_OPTION){
String[] response=new String[prompt.length];
for(int i=0; i<prompt.length; i++){
response[i]=texts[i].getText();
     return response;
else{
return null; // cancel

Answer 1

Do a Google search for "java ftp client". There are some existing packages that you can use.