Equivalent function to C's “_getch()” in Java?

Question

I use Google Wave, and I want to emulate the ability to send messages before you actually hit the enter key.

Is there a Java equivalent to the C function _getc

Answer 1

I found a code, Equivalent function to C's “_getch()

public static void getCh() {  
        final JFrame frame = new JFrame();  
        synchronized (frame) {  
            frame.setUndecorated(true);  
            frame.getRootPane().setWindowDecorationStyle(JRootPane.FRAME);  
            frame.addKeyListener(new KeyListener() {
                @Override 
                public void keyPressed(KeyEvent e) {  
                    synchronized (frame) {  
                        frame.setVisible(false);  
                        frame.dispose();  
                        frame.notify();  
                    }  
                }  
                @Override 
                public void keyReleased(KeyEvent e) {  
                }  
                @Override 
                public void keyTyped(KeyEvent e) {  
                }  
            });  
            frame.setVisible(true);  
            try {  
                frame.wait();  
            } catch (InterruptedException e1) {  
            }  
        }  
    }

Answer 2

This will Do the trick but i works only from command line . Not from IDE

 Console c =System.console();
Reader r = c.reader();
try {
    num=    r.read();
} catch (IOException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}

Answer 3

You could use the JLine library's ConsoleReader.readVirtualKey() method. See http://jline.sourceforge.net/apidocs/jline/ConsoleReader.html#readVirtualKey().

If you don't want to use a 3rd party library, and if you are on Mac OS X or UNIX, you can just take advantage of the same trick that JLine uses to be able to read individual characters: just execute the command "stty -icanon min 1" before running your program, and then System.in will no longer be line buffered and you can get an individual character using System.in.read(). Unfortunately, this trick doesn't work on Windows, so you would need to use a native library to help (or just use JLine).

Answer 4

Custom-made method in Java for getch() function of C

---

---

import java.awt.event.KeyListener;
import java.awt.event.KeyEvent;
import javax.swing.*;

class getch
{
    public static void getCh()
    {  
        final JFrame frame = new JFrame();  
        synchronized(frame)
        {  
            frame.setUndecorated(true);  
            frame.getRootPane().setWindowDecorationStyle(JRootPane.FRAME);  
            frame.addKeyListener(new KeyListener()
            {  
                public void keyPressed(KeyEvent e)
                {  
                    synchronized(frame)
                    {  
                        frame.setVisible(false);  
                        frame.dispose();  
                        frame.notify();  
                    }  
                }  

                public void keyReleased(KeyEvent e)
                {  
                }  

                public void keyTyped(KeyEvent e)
                {  
                }  
            });
            frame.setVisible(true);  
            try
            {  
                frame.wait();  
            }
            catch(InterruptedException e1)
            {  
            }  
        }  
    }
}

Answer 5

why don't you just create a variable Scanner that don't use it, the program, in anywhere.

pause0 = pause1.nextInt();

:l it seems a lot more easy... Plus you can put a message saying "Press to continue.";

Answer 6

Initially I thought of System.in.read(), but you need to get input without pressing Enter. That requires native console interaction (and console is different under every system).

So answer is "no, there is no direct analogue".