这个是java版本的pl0语言的词法分析器,带有图形界面,很好的

				package myCompiler;
				
				import java.awt.BorderLayout;
				import javax.swing.JPanel;
				import javax.swing.JFrame;
				
				public class f extends JFrame {
				
					private static final long serialVersionUID = 1L;
				
					private JPanel jContentPane = null;
				
					/**
					 * This is the default constructor
					 */
					public f() {
						super();
						initialize();
					}
				
					/**
					 * This method initializes this
					 * 
					 * @return void
					 */
					private void initialize() {
						this.setSize(300, 200);
						this.setContentPane(getJContentPane());
						this.setTitle("JFrame");
					}
				
					/**
					 * This method initializes jContentPane
					 * 
					 * @return javax.swing.JPanel
					 */
					private JPanel getJContentPane() {
						if (jContentPane == null) {
							jContentPane = new JPanel();
							jContentPane.setLayout(new BorderLayout());
						}
						return jContentPane;
					}
				
				}