java二级试卷23

public class Java_1
{
   //*********Found**********
   public  static  void main (String args[])
   {
      new SimpleThread("第1").start();
      new SimpleThread("第2").start();
   }
} 

//*********Found**********
class SimpleThread extends Thread
{
   public SimpleThread(String str)
   {
      super(str);
   }
   public void run()
   {
      for (int i = 0; i < 5; i++)
      {
   //*********Found**********
         System.out.println(i + " " + getName());
         try
         {
            sleep((int)(2 * 100));
         }
         catch (InterruptedException e) { }
      }
      System.out.println("运行! " + getName());
   }
}

import java.text.*;

public class Java_2
{
   public static void main(String[] args)
   {
      Person[] people = new Person[2];
      people[0] = new Worker("老张", 30000);
      people[1] = new Student("小王", "计算机科学");
      for (int i = 0; i < people.length; i++)
      {
         Person p = people[i];
         //*********Found**********
         System.out.println(p.getName() + ", " + p.getDescription());
      }
   }
}

//*********Found**********
abstract class Person
{
   public Person(String n)
   {
     name = n;
   }
//*********Found**********
   public abstract String getDescription();
   public String getName()
   {
     return name;
   }
   private String name;
}

//*********Found**********
class Worker extends Person
{
   public Worker(String n, double s)
   {
      super(n);
      salary = s;
   }
   public String getDescription()
   {
      NumberFormat formatter = NumberFormat.getCurrencyInstance();
      return "工人，年薪是 " + formatter.format(salary) + "。";
   }
   private double salary;
}

//*********Found**********
class Student extends Person
{
   public Student(String n, String m)
   {
      super(n);
      major = m;
   }
   public String getDescription()
   {
      return "学生，专业是 " + major + "。";
   }
   private String major;
}

import java.awt.*;
import java.awt.event.*;
import java.io.*;
import javax.swing.*;

public class Java_3
{
   public static void main(String[] args)
   {
      JFrame frame = new ImageViewerFrame();
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      //*********Found**********
      frame.setVisible(true);
   }
}

class ImageViewerFrame extends JFrame
{
   private JLabel label;
   private JLabel labelT;
   private JFileChooser chooser;
   private JComboBox faceCombo;
   private static final int DEFAULT_SIZE = 24;
   public static final int DEFAULT_WIDTH = 570;
   public static final int DEFAULT_HEIGHT = 400;

   public ImageViewerFrame()
   {
      setTitle("ImageViewer");
      setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
      label = new JLabel();
      Container contentPane = getContentPane();
      contentPane.add(label,BorderLayout.CENTER);
      chooser = new JFileChooser();
      chooser.setCurrentDirectory(new File("."));
      JMenuBar menuBar = new JMenuBar();
      setJMenuBar(menuBar);
      //*********Found**********
      JMenu menu = new JMenu("file");
      menuBar.add(menu);
      JMenuItem openItem = new JMenuItem("Open");
      //*********Found**********
      menu.add(openItem);
      openItem.addActionListener(new ActionListener()
         {  
            public void actionPerformed(ActionEvent evt)
            {  
               int r = chooser.showOpenDialog(null);
               if(r == JFileChooser.APPROVE_OPTION)
               {  
          //*********Found**********
                  String name = chooser.getSelectedFile().getPath();
                  label.setIcon(new ImageIcon(name));
               }
            }
         });
      labelT = new JLabel("红军不怕远征难");
      labelT.setFont(new Font("隶书", Font.PLAIN, DEFAULT_SIZE));
      contentPane.add(labelT, BorderLayout.NORTH );
      faceCombo = new JComboBox();
      faceCombo.setEditable(true);
      faceCombo.addItem("隶书");
      faceCombo.addItem("华文新魏");
      faceCombo.addItem("华文行楷");
      faceCombo.addItem("华文隶书");
      faceCombo.addActionListener(new
         ActionListener()
         {  
            public void actionPerformed(ActionEvent event)
            {
       //*********Found**********
               labelT.setFont(new Font((String)faceCombo.getSelectedItem(),
                  Font.PLAIN, DEFAULT_SIZE));
            }
         });
      JPanel comboPanel = new JPanel();
      comboPanel.add(faceCombo);
      contentPane.add(comboPanel, BorderLayout.SOUTH);
   }
}