import javax.swing.*;
import java.awt.event.*;
public class KS1
{ JButton a,b;
	public JTextField t1,t2,t3,t4;
	GDFrame ks;
	public KS1()
	{
	 ks=new GDFrame("凱撒密碼");
	 ks.show();
   a=ks.getB1();
   b=ks.getB2();
   a.addActionListener(new Ba());	
   b.addActionListener(new Bb());		
	
	 t1=ks.getT1();
	 t2=ks.getT2();
	 t3=ks.getT3();
	 t4=ks.getT4();
	
	}

class Ba implements ActionListener{
	public void actionPerformed(ActionEvent e)
	{
	 String m,k,cc;
	 char t,mm[]=new char[50],c[]=new char[50];
	 int len,kv;                       //  kv為輸入k的數(shù)值
	 m=t1.getText();                  //文本1里面的字符串,明文
	 k=t2.getText();                  //密鑰輸入的字符串
	 kv=Integer.parseInt(k);             
	 mm=m.toCharArray();                 //明文字符轉(zhuǎn)換成數(shù)值存于mm中
   len=m.length(); 
   for(int i=0;i<len;i++)
      {
       t=(char)(mm[i]+kv);
       if(t>'z')
        t=(char)(t-26);
       c[i]=t;
       }
   cc=new String(c,0,len);
   t3.setText(cc);    
	// System.out.println(m+"   "+n);
	}
}	
class Bb implements ActionListener{
	public void actionPerformed(ActionEvent e)
	{
	   char sm2[]=new char[50],t;           //sm2用于存放解密后的明文
   String c1,m,k;                         //m存放解密后的明文的字符串
   int len,kv;
   k=t2.getText();  
   kv=Integer.parseInt(k);
   c1=t3.getText();
   len=c1.length();
   for(int i=0;i<len;i++)
       {t=(char)(c1.charAt(i)-kv);
       	  if(t<'a')  t=(char)(t+26);
       	sm2[i]=t;
       	}
  m=new String(sm2,0,len);    	    
  t4.setText(m);
       	   }
       	} 	

}