set anti-alias for graphics:
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING，
RenderingHints.VALUE_ANTIALIAS_ON);
set anti-alias for components:
// Making a JTextArea use anti-Alias fonts
// only works in JDK 1.5+
jtextArea.putClientProperty(
com.sun.java.swing.SwingUtilities2.AA_TEXT_PROPERTY_KEY,
Boolean.TRUE );