Using System.setIn to Change the InputStream

[Qwerty Werty]

Hi All

I am trying to change my System.in InputStream to instead take values from the terminal window but take values from a JEditorPane or JTextBox.

I have this to add the text to the new InputStream which has been declared.

GUI Class:
public static InputStream consoleInputStream;
...
sendButton.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent e) {
        String message = sendPane.getText();
        consoleInputStream = new ByteArrayInputStream(message.getBytes());
        sendPane.setText("");
    }
});
 

I then want to use this in another class to output the text:

System.setIn(GUI.consoleInputStream);
...
public static String readLine() {
    String s = null;
    BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
    try {
        s = in.readLine();
    } catch (IOException e) {
        e.printStackTrace();
    }
    return s;
}
 

But I get java.lang.NullPointerException at java.io.Reader. (Unknown Source) at java.io.InputStreamReader. (Unknown Source).

What I have is a CLI applciation that runs off the User inputs from the terminal within Eclipse all I want to do is change main System.in input Stream to a Jtextbox output. I have the above working just in CLI (of course not setting System.setIn()...)

Any pointers would be awsome!