import java.awt.BorderLayout;

import javax.swing.JFrame;
import javax.swing.JTextPane;
import javax.swing.SwingUtilities;
import javax.swing.border.EtchedBorder;
import javax.swing.text.BadLocationException;
import javax.swing.text.Document; 

public class Test1_ChangeStyleAndAppend extends JFrame { 
	class MyJTextPane extends JTextPane { 
		/** 
		 * Append some text to this pane. 
		 * @param s 
		 */ 
		public void append(String s) { 
			try { 
				Document doc = this.getDocument(); 
				doc.insertString(doc.getLength(), s, null); 
			} catch(BadLocationException e) { 
				System.err.println(e); 
			} 
		} 

		/** 
		 * Append some text and change line. 
		 * @param s 
		 */ 
		public void appendLine(String s) { 
			try { 
				Document doc = this.getDocument(); 
				doc.insertString(doc.getLength(), s + System.lineSeparator(), null); 
			} catch(BadLocationException e) { 
				System.err.println(e); 
			} 
		} 

		// @Override 
		// public String getText() { 
		// String string = ""; 
		// try { 
		// string = this.getDocument().getText(0, this.getDocument().getLength()); 
		// } catch (BadLocationException e) { 
		// e.printStackTrace(); 
		// } 
		// return string; 
		// } 
	} 
	public Test1_ChangeStyleAndAppend() { 
		begin(); 
	} 

	private void begin() { 
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
		setLayout(new BorderLayout()); 
		MyJTextPane pane0 = new MyJTextPane(); 
		pane0.appendLine("MyJTextPane using append() and then calling setText()"); 
		pane0.appendLine("Second line. "); 
		pane0.appendLine("Third line"); 
		pane0.setText(pane0.getText() + "At last" + System.lineSeparator()); 
		pane0.setBorder(new EtchedBorder(EtchedBorder.RAISED)); 
		add(pane0, BorderLayout.NORTH); 

		MyJTextPane pane = new MyJTextPane(); 
		// changeLineSpacing(pane, 1.5f, false); 
		pane.appendLine("MyJTextPane calling appendLine()"); 
		pane.appendLine("Second line. "); 
		pane.appendLine("Third line"); 
		pane.appendLine("At last"); 
		pane.setBorder(new EtchedBorder(EtchedBorder.RAISED)); 
		add(pane, BorderLayout.CENTER); 


		JTextPane pane2 = new JTextPane(); 
		pane2.setText("Normal JTextPane calling setText()"); 
		pane2.setText(pane2.getText() + System.lineSeparator() + "Second line. "); 
		pane2.setText(pane2.getText() + System.lineSeparator() + "Third line"); 
		pane2.setText(pane2.getText() + System.lineSeparator() + "At last"); 
		pane2.setBorder(new EtchedBorder(EtchedBorder.RAISED)); 
		add(pane2, BorderLayout.SOUTH); 

		pack(); 
		setVisible(true); 
	} 

	public static void main(String[] args) { 
		SwingUtilities.invokeLater(new Runnable() { 

			@Override 
			public void run() { 
				Test1_ChangeStyleAndAppend frame = new Test1_ChangeStyleAndAppend(); 

			} 

		}); 
	} 
}