我学的第一个代码量较大的GUI方面的java源程序

/****************************************
*程序文件名称：TextFindReplace.java
*功能：字符串的查找与替换
*****************************************/
 import java.awt.*;
 import java.awt.event.*;
 
 public class TextFindReplace implements MouseListener,WindowListener{
 	private Frame frObj;
 	private TextArea taObj;
 	private TextField tfObj1,tfObj2;
 	private Button buttonObj1;
 	private Button buttonObj2;
 	private Button buttonObj3;
 	private Panel pObj1,pObj2,pObj3,pObj4,pObj5;
 	private Label labObj1,labObj2,labObj3;
 	boolean boolObj=false;
 	Dialog  diaObj;
 	Label   textLab;
 	Button  butObj2=new Button("OK");
 	
 	public static void main(String[] args){
 		TextFindReplace examObj=new TextFindReplace();
 		examObj.create();//通过使用成员方法进行实例化各对象等操作.
 		} 
 	public void create(){
 		frObj=new Frame("文本的查找与替换");
 		taObj=new TextArea();
 		tfObj1=new TextField();
 		tfObj2=new TextField();
 		buttonObj1=new Button("Find");
 		buttonObj2=new Button("Replace");
 		buttonObj3=new Button("Exit");
 		labObj1=new Label("文本区域：");
 		labObj2=new Label("待查找或替换前的字符串：");
 		labObj3=new Label("替换后的字符串：");
 		pObj1=new Panel();
 		pObj2=new Panel();
 		pObj3=new Panel();
 		pObj4=new Panel();
 		pObj5=new Panel();
 		pObj1.setLayout(new BorderLayout());//先设置布局,再添加和组件
 		pObj1.add("North",labObj1);
 		pObj1.add("Center",taObj);//BorderLayout中"CENTER"大小会随窗口的大小改变
 		
 		pObj2.setLayout(new BorderLayout());
 		pObj2.add("North",labObj2);
 		pObj2.add("Center",tfObj1);
 		
 		pObj3.setLayout(new BorderLayout());
 		pObj3.add("North",labObj3);
 		pObj3.add("Center",tfObj2);
 		
 		pObj4.setLayout(new FlowLayout(FlowLayout.CENTER,20,20));
 		pObj4.add(buttonObj1);//(20,20)？前者指对象间水平间距,后者指对象距上边界的距离
 		pObj4.add(buttonObj2);
 		pObj4.add(buttonObj3);
 		
 		pObj5.setLayout(new GridLayout(3,1));//(3,1)3行，1列的等大小布局
 		pObj5.add(pObj2);		
 		pObj5.add(pObj3);
 		pObj5.add(pObj4);
 		
 		frObj.setLayout(new GridLayout(1,2));
 		frObj.add(pObj1);
 		frObj.add(pObj5);
 		
 		buttonObj1.addMouseListener(this);//监听者this指当前对象buttonObj1
 		buttonObj2.addMouseListener(this);//监听者为实现了相应接口的类对象
 		buttonObj3.addMouseListener(this);
 		
 		frObj.addWindowListener(this);
 		frObj.setSize(400,260);
 		frObj.setVisible(true);
 		
 		diaObj=new Dialog(frObj);//***参数是Frame对象***实现Frame和Dialog之间的通信
 		diaObj.setLayout(new FlowLayout(FlowLayout.CENTER,40,20));
 		textLab=new Label("");
 		diaObj.add(textLab);
 		diaObj.add(butObj2);
 		butObj2.addMouseListener(this);
 		diaObj.setSize(200,100);
 		//diaObj2使用默认false，而不用diaObj2.setVisible(false);且下方已有：diaObj.show();		
 			}
 		
 		public void mouseClicked(MouseEvent e){
 			Button butObj=(Button)(e.getSource());//***(Button)(e.getSource())***
 			if(butObj.getLabel()=="Exit")         //***通过getLabel()可获得Button上的文本***
 				{	
 					System.exit(0);//关闭窗口
 					
 				}
 			if(butObj.getLabel()=="Find"||butObj.getLabel()=="Replace")
 				{
 					String strObj1=taObj.getText();//***通过getText()可获得TextArea或TextField中的文本内容***
 					String strObj2=tfObj1.getText();
 					int matchNum=0;
 					int cursorPos=taObj.getCaretPosition();//***通过getCaretPosition()可获得TextArea等中的光标位置***
 					matchFun classObj=new matchFun();//***自定义类matchFun***
 					if(butObj.getLabel()=="Find")
 						{
 							matchNum=classObj.strFind(strObj1,strObj2,cursorPos);
 							textLab.setText("共找到"+matchNum+"处");
 							diaObj.show();//隐藏，触发，计算，设值，显示
 						}
 					if(butObj.getLabel()=="Replace")
 						{
 							String strObj3=tfObj2.getText();
 							matchNum=classObj.strReplace(strObj1,strObj2,strObj3,cursorPos);
 							textLab.setText("共替换到"+matchNum+"处");
 							StringBuffer taText=classObj.repStr;//***
 							taObj.setText(taText.toString());//***
 							diaObj.show();//***
 						}
 					
 				}
 			if(butObj.getLabel()=="OK")
 				{diaObj.hide();
 				 frObj.show(); 				
 				}
 			}
 		public void mouseEntered(MouseEvent e){}//***具体的使用方法及其效果?
 		public void mouseExited(MouseEvent e){}
 		public void mousePressed(MouseEvent e){}
 		public void mouseReleased(MouseEvent e){}
 		public void windowClosing(WindowEvent e ){//***用于窗口控制
 			System.exit(0);
 			}
 		public void windowOpened(WindowEvent e){}
 		public void windowIconified(WindowEvent e){}//***具体的使用方法及其效果?
 		public void windowDeiconified(WindowEvent e){}
 		public void windowClosed(WindowEvent e){}
 		public void windowActivated(WindowEvent e){}
 		public void windowDeActivated(WindowEvent e){}
 	}
 
 /*类matchFun用于处理有关字符串查找和替换算法*/
 class matchFun{
	StringBuffer repStr;
	public int strFind(String s1,String s2,int pos)
		{
		int i,j,k=0;
		i=pos;
		j=0;
		while(i<s1.length()&&j<s2.length())
			{
				if(s1.charAt(i)==s2.charAt(j))
				{
					++i;++j;
					if(j==s2.length())
					{
						k+=1;
						i=i-j+1;
						j=0;
					}
				}
				else{i=i-j+1;j=0;}
			}
		return k;
		}
	public int strReplace(String s1,String s2,String s3,int pos){
		int i,j,k=0;
		i=pos;
		j=0;
		repStr=new StringBuffer(s1);//***为了使用replacea()方法，且repStr被申明为实例量。
		while(i<repStr.length()&&j<s2.length())
		{
				if(repStr.charAt(i)==s2.charAt(j))
				{	++i;++j;
					if(j==s2.length())
					{
						k=k+1;
						repStr.replace(i-j,i,s3);//***replace(i-j,i,s3)，i-j:起始位置，i：结束位置，s3：替换字符串
						j=0;
					}
				}
				else{i=i-j+1;j=0;}
			}
		return k;
		}
 	}