Replace the first 3 characters with some text : JTextArea « Swing « Java Tutorial

1. Java Tutorial
2. Swing
3. JTextArea

import javax.swing.JTextArea;

public class Main {
  public static void main(String[] argv) {
    JTextArea ta = new JTextArea("Initial Text");
    int start = 0;
    int end = 3;
    ta.replaceRange("new text", start, end);
  }
}

14.16.JTextArea
	14.16.1.	JTextArea: for multiple-line input.
	14.16.2.	Setting JTextArea Line Wrap and Wrap Style
	14.16.3.	Using JTextArea
	14.16.4.	Set font for I18N to JTextArea
	14.16.5.	Hello in Japanese
	14.16.6.	Using Actions with Text Components: JTextArea
	14.16.7.	Copy selected text from one text area to another
	14.16.8.	Modifying Text in a JTextArea Component
	14.16.9.	Insert some text after the 5th character
	14.16.10.	Append some text to JTextArea
	14.16.11.	Replace the first 3 characters with some text
	14.16.12.	Delete the first 5 characters
	14.16.13.	Enumerating the Lines in a JTextArea Component
	14.16.14.	Setting the Tab Size of a JTextArea Component
	14.16.15.	Moving the Focus with the TAB Key in a JTextArea Component
	14.16.16.	Customizing a JTextArea Look and Feel
	14.16.17.	Highlight of discontinous string
	14.16.18.	Setting text drag in a JTextArea
	14.16.19.	Enumerate the content elements with a ElementIterator