ch6_e6_16.java

《java语言与面向对象程序设计题解及实验指导》源代码

import java.applet.*; 
import java.awt.*;
import java.awt.event.*;

public class ch6_e6_16 extends Applet implements ActionListener
{
    String originalString, modifiedString;
    int delChar;
    
    Label orgStringLbl = new Label("原始字符串：");
    Label delCharLbl = new Label("需去除字符：");
    TextField orgStringTfd = new TextField(20);
    TextField delCharTfd = new TextField(1);
    Button modifyBtn = new Button("删除字符");
    
    public void init()
    {
        add(orgStringLbl);
        add(orgStringTfd);
        add(delCharLbl);
        add(delCharTfd);
        add(modifyBtn);
        
        orgStringTfd.setText("");
        delCharTfd.setText("");
        originalString = "";
        modifiedString = "";
        
        modifyBtn.addActionListener(this);
    }
    
    public void paint(Graphics g)
    {
        g.drawString(modifiedString, 10, 150);
    }
    
    public void actionPerformed(ActionEvent ae)
    {
        if(ae.getSource() == modifyBtn)
        {
            originalString = orgStringTfd.getText();
            delChar = (int)(delCharTfd.getText().charAt(0));
            
            modifiedString = "";
            int i=0, j=0;
            while( (j=originalString.indexOf(delChar,i)) != -1 )
            {
                System.out.println(i + "," + j + "," + (j-i));
                System.out.println(originalString);
                modifiedString = modifiedString
                    + originalString.substring(i,j);
                System.out.println(modifiedString);
                i = j+1;
            }
            modifiedString = modifiedString 
                + originalString.substring(i,originalString.length());
            repaint();
        }
        else
        {
            showStatus("事件" + ae.toString() + "未定义处理操作。");
            orgStringTfd.setText("");
            delCharTfd.setText("");
            originalString = "";
            modifiedString = "";
        }
    }
    
}