Main.java Source code

Introduction

Here is the source code for Main.java

Source

import javax.swing.JFrame;
import javax.swing.JTextArea;
import javax.swing.text.AbstractDocument;
import javax.swing.text.AttributeSet;
import javax.swing.text.BadLocationException;
import javax.swing.text.DocumentFilter;

public class Main {
    public static void main(String[] args) {
        DocumentFilter dfilter = new UpperCaseFilter();

        JTextArea jta = new JTextArea();
        ((AbstractDocument) jta.getDocument()).setDocumentFilter(dfilter);

        JFrame frame = new JFrame("UpcaseFilter");
        frame.getContentPane().add(jta, java.awt.BorderLayout.CENTER);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(200, 120);
        frame.setVisible(true);
    }

}

class UpperCaseFilter extends DocumentFilter {

    public void insertString(DocumentFilter.FilterBypass fb, int offset, String text, AttributeSet attr)
            throws BadLocationException {
        fb.insertString(offset, text.toUpperCase(), attr);
    }

    public void replace(DocumentFilter.FilterBypass fb, int offset, int length, String text, AttributeSet attr)
            throws BadLocationException {
        fb.replace(offset, length, text.toUpperCase(), attr);
    }

}