I am in need of some direction. Not sure if I am on the right path but I think so. I am trying to create a telnet java program that will connect to a client machine, execute a single command then disconnect. I am able to get the program to work and readout the InputStream to a Text field ( for testing purposes) when I connect to a linux machine or my router. But when I connect to a Windows machine or other client computer, it doens't work. It reads out some random characters, then locks up.
Below is my code. I have seen examples of other code out there as well as API's from Apache for example. I would really like to see if I can get this to work with just Java Sockets.
public class TestSockets extends JFrame implements ActionListener {
/**
* @param args
*/
private String USER = "User";
private String PASS = "Password01";
private final static String CMD = "exit\r\n";
private static Socket telnet = null;
private PrintWriter writer = null;
private static InputStream reader = null;
private String host = "192.168.1.1";
private int port = 23;
TextArea javatext;
public static void main(String[] args) {
// TODO Auto-generated method stub
new TestSockets().setVisible(true);
}
private TestSockets() {
super("Testing Buttons");
//Set JFrame size
setSize(500, 600);
//Gives JFrame a location
setLocation(100, 100);
//set layout
setLayout(new FlowLayout());
javatext = new TextArea(25, 65);
add(javatext);
//Ask for window decorations provided by the look and feel.
JFrame.setDefaultLookAndFeelDecorated(true);
JButton button3 = new JButton("Run Program");
button3.addActionListener(this);
add(button3);
}
@Override
public void actionPerformed(ActionEvent arg0) {
// TODO Auto-generated method stub
try {
telnet = new Socket(host, port);
telnet.setKeepAlive(true);
//reader = telnet.getInputStream();
writer = new PrintWriter(telnet.getOutputStream());
reader = telnet.getInputStream();
//out = telnet.getOutputStream();
//Process p = Runtime.getRuntime().exec("telnet " + server.toString(), null, null);
//DataOutputStream os = new DataOutputStream(p.getOutputStream());
//DataInputStream in = new DataInputStream(p.getInputStream());
StringBuilder sb = new StringBuilder();
byte[] buffer = new byte[4096]; // Read 4K characters at a time
int len; // How many chars read each time
while ((len = reader.read(buffer)) != -1) {
String readchar = new String(buffer, 0, len);
sb.append(readchar + "\n");
System.out.println(readchar);
javatext.append(readchar);
if (readchar.endsWith("login: ")) {
writer.print(USER + "\r\n");
writer.flush();
}
if (readchar.endsWith("Password: ")) {
writer.print(PASS + "\r\n");
writer.flush();
}
if (readchar.endsWith("password: ")) {
writer.print(PASS + "\r\n");
writer.flush();
}
if (readchar.endsWith("# ")) {
writer.print(CMD);
writer.flush();
}
if (readchar.endsWith("# ")) {
writer.print(CMD);
writer.flush();
}
}
} catch (SocketException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
Thanks for everyones help. I was really trying to get this to work in Android but just was making a rough draft in straight Java app. I got the rough idea and it works. It just repeats all the characters in my StringBuilder over and over if I read the output. Not a big concern, I am not trying to display the output really anyway. Here is what I finished with. Hope this helps anyone else if needed.
public class AndroidSocket extends Activity implements OnClickListener {
TextView text;
EditText edit1, edit2, edit3, edit4;
private String USER = null;
private String PASS = null;
Editable server, username, password, command;
private String CMD = null;
private PrintStream writer = null;
private static BufferedReader reader = null;
private String host = null;
private int port = 23;
private TelnetClient telnet = new TelnetClient();
private InputStream in;
private PrintStream out;
StringBuffer sb;
Handler mHandler = new Handler();
int len;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
text = (TextView)findViewById(R.id.text);
edit1 = (EditText)findViewById(R.id.edit1);
edit2 = (EditText)findViewById(R.id.edit2);
edit3 = (EditText)findViewById(R.id.edit3);
edit4 = (EditText)findViewById(R.id.edit4);
server = edit1.getEditableText();
username = edit2.getEditableText();
password = edit3.getEditableText();
command = edit4.getEditableText();
Button button = (Button)findViewById(R.id.button);
button.setOnClickListener(this);
text.setText("Android Socket" + "\n");
}
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
text.setText("Android Socket" + "\n");
try {
telnet.connect(server.toString(), 23);
in = telnet.getInputStream();
out = new PrintStream(telnet.getOutputStream());
reader = new BufferedReader(new InputStreamReader(telnet.getInputStream()));
writer = new PrintStream(telnet.getOutputStream());
telnet.setKeepAlive(true);
Thread mThread = new Thread(new Runnable() {
@Override
public void run() {
// TODO Auto-generated method stub
try {
sb = new StringBuffer();
//char[] buffer = new char[1024];
while (true)
{
len = in.read();
String s = Character.toString((char)len);
sb.append( s );
AndroidSocket.this.mHandler.post(new Runnable(){
@Override
public void run() {
// TODO Auto-generated method stub
AndroidSocket.this.text.getText();
AndroidSocket.this.text.append( sb.toString() );
}
});
System.out.println( sb );
mylogin();
mypass();
mycommand();
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
});
mThread.start();
}
catch (Exception e) {
e.printStackTrace();
}
}
private void mycommand() throws IOException {
// TODO Auto-generated method stub
if (sb.toString().endsWith("> ")) {
out.println(command.toString() + "\r\n");
out.flush();
out.println("exit\r\n");
out.flush();
try {
TimeUnit.SECONDS.sleep(10);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
disconnect();
} else
if (sb.toString().endsWith("# ")) {
out.println(command.toString() + "\r\n");
out.flush();
out.println("exit\r\n");
out.flush();
try {
TimeUnit.SECONDS.sleep(10);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
disconnect();
}
}
private void mypass() {
// TODO Auto-generated method stub
if (sb.toString().endsWith("Password: ")) {
out.println(password.toString() + "\r\n");
out.flush();
} else
if (sb.toString().endsWith("password: ")) {
out.println(password.toString() + "\r\n");
out.flush();
}
}
private void mylogin() {
// TODO Auto-generated method stub
if (sb.toString().endsWith("login: ")) {
out.println(username.toString() + "\r");
out.flush();
}
}
public void disconnect() {
try {
in.close();
out.close();
telnet.disconnect();
}
catch (Exception e) {
e.printStackTrace();
}
}
}