framede.java

java课后题的详细答案

//package FrameDe;

import java.awt.Button;
import java.awt.Color;
import java.awt.Frame;
import java.awt.Label;
import java.awt.TextField;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import java.security.Key;


public class framede{

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		f_frame f = new f_frame();
	}

}
class f_frame extends JFrame implements ActionListener{
	
	String coverText,ciperText;
	byte[] plainText,cipherText,newPlainText;
	Key key;
	KeyGenerator KeyGen;
	Cipher  cipher;

	TextField	tfid0,tfid1,tfid2;
	Label	id0,id1,id2;
	Button buttonO,buttonD;
	f_frame(){
		super("加密解密");
		setLayout(null);
		setLocation(200, 200);
		setVisible(true);
		setSize(450,400);
		getContentPane().setBackground(Color.green);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		id0 = new Label("明文:");
		id1 = new Label("密文:");
		id2 = new Label("解析:");
		tfid0 = new TextField();
		tfid1 = new TextField();
		tfid2 = new TextField();
		buttonO = new Button("输出密文");
		buttonD = new Button("解析密文");
		id0.setBounds(30, 100, 40, 20);
		id1.setBounds(30, 140, 40, 20);
		id2.setBounds(30, 180, 40, 20);
		tfid0.setBounds(100, 100, 300, 20);
		tfid1.setBounds(100, 140, 300, 20);
		tfid2.setBounds(100, 180, 300, 20);
		buttonO.setBounds(130,250,80,30);
		buttonD.setBounds(250,250,80,30);
		add(id0);
		add(id1);
		add(id2);
		add(tfid0);
		add(tfid1);
		add(tfid2);
		add(buttonO);
		add(buttonD);
		buttonD.setEnabled(false);
		buttonO.addActionListener(this);
		buttonD.addActionListener(this);
	}
	public void actionPerformed(ActionEvent e){

		if(e.getSource() == buttonO){
			String text = tfid0.getText().trim();
			if(text.length() == 0){
				
				JOptionPane.showMessageDialog(null, "明文不能为空");	
			}else{
				try {
					
					encryption_ActionPerformed();
					buttonD.setEnabled(true);
					JOptionPane.showMessageDialog(null, "加密成功");
					
				} catch (Exception e1) {
					// TODO Auto-generated catch block
					e1.printStackTrace();
				}
			}
		}
		if(e.getSource() == buttonD){
			
			try {
				decryption_ActionPerformed();
				buttonD.setEnabled(false);
			} catch (Exception e1) {
				// TODO Auto-generated catch block
				e1.printStackTrace();
			}
			JOptionPane.showMessageDialog(null, "解密成功");
		}
	}
	
	public void encryption_ActionPerformed() throws Exception{
		
		coverText = tfid0.getText().trim();
    	plainText=coverText.getBytes();
    	KeyGen=KeyGenerator.getInstance("DES");
    	KeyGen.init(56);
    	key=(Key) KeyGen.generateKey();
    	cipher=Cipher.getInstance("DES/ECB/PKCS5Padding");
    	cipher.init(Cipher.ENCRYPT_MODE,  (java.security.Key) key);
    	cipherText=cipher.doFinal(plainText);
    	tfid1.setText(new String(cipherText,"UTF8"));
    }
	
	public void decryption_ActionPerformed() throws Exception{
		
    	cipher.init(Cipher.DECRYPT_MODE, (java.security.Key) key);
    	newPlainText=cipher.doFinal(cipherText);
        tfid2.setText((new String(newPlainText, "UTF8")));
    	
    }
}