Lập trình JAVA Desktop từ A tới Z - phần 4

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Tiếp theo loạt bài về Lập trình JAVA Desktop từ A tới Z - phần 4. Xem thêm các phần trước ở bên dưới.
Nội dung file mã hóa Frame
EncryptFrame.java
Khai báo và nhập các gói cần thiết.

package com.pissoft.session1;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import javax.swing.BorderFactory;
import javax.swing.Box;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField; 

Khai báo các thuộc tính và hàm thành viên trong lớp EncryptFrame

public class EncryptFrame extends JFrame{
private static final long serialVersionUID = -4229685511765327513L;
private JLabel lblSource = new JLabel("Source: ", JLabel.RIGHT);
private JTextField txtSource = new JTextField();
private JLabel lblAlgorithm = new JLabel("Algorithm: ", JLabel.RIGHT);
private JComboBox cbAlgorithm = new JComboBox(new String[]{"SHA-1","MD2", "MD5"});
private JLabel lblDest = new JLabel("Dest: ", JLabel.RIGHT);
private JTextField txtDest = new JTextField();
private JButton btnEncrypt = new JButton("Encrypt");
private JButton btnCheck = new JButton("Check");
public EncryptFrame(){
super("Encrypt Demo");
initFrame();
buidGUI();
registerListener();
setVisible(true);
}
private void initFrame(){
//Put frame at the center of the Desktop
int frameX = (Toolkit.getDefaultToolkit().getScreenSize().width- getWidth()) / 2;
int frameY = (Toolkit.getDefaultToolkit().getScreenSize().height- getHeight()) / 2;
this.setLocation(frameX, frameY);
//Require app end when frame closed
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
private void buidGUI(){
GridBagLayoutEx layout = new GridBagLayoutEx();
setLayout(layout);
add(lblSource, layout.createFixedConstraints());
add(txtSource, layout.createHorzGlueConstraints());
layout.newRow();
add(lblAlgorithm, layout.createFixedConstraints());
add(cbAlgorithm, layout.createHorzGlueConstraints());
layout.newRow();
add(lblDest, layout.createFixedConstraints());
add(txtDest, layout.createHorzGlueConstraints());
layout.newRow();
add(Box.createVerticalGlue(), layout.createMergeAllGlueConstraints());
layout.newRow();
JPanel pnlController = new JPanel();
add(pnlController, layout.createMergeAllHorzGlueConstraints());
pnlController.setLayout(new BoxLayout(pnlController,BoxLayout.X_AXIS));
pnlController.add(Box.createHorizontalGlue());
pnlController.add(btnEncrypt);
pnlController.add(Box.createHorizontalStrut(4));
pnlController.add(btnCheck);
pack();
}
private void registerListener(){
btnEncrypt.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e) {
String dest = encrypt(txtSource.getText(),(String)cbAlgorithm.getSelectedItem());
txtDest.setText(dest);
}
});
btnCheck.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e) {
Boolean isSuccessed = check(txtDest.getText(),txtSource.getText(), (String)cbAlgorithm.getSelectedItem());
String message[]={"Fail", "Successful"};
JOptionPane.showMessageDialog(EncryptFrame.this,message[isSuccessed?1:0]);
}
});
}
public String encrypt(String source, String algorithm){
MessageDigest digester=null;
try {
digester = MessageDigest.getInstance(algorithm);
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
}
if(digester==null)
return null;
byte dest[] = digester.digest(source.getBytes());
return new String(dest);
}
public boolean check(String secret, String source, String algorithm){
return secret.equals(encrypt(source, algorithm));
}
}

Nội dung file GridBagLayoutEx.java

package com.pissoft.session1;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
public class GridBagLayoutEx extends GridBagLayout {
/**
*/
private static final long serialVersionUID = 556538646538435067L;
private int row=0;
private int column=0;
public void newRow(){
row++;
column=0;
}
public void newColumn(){
column++;
}
/**
* Create fixed both side constraints
* @param pLeftBoundary
* @return
*/
public GridBagConstraints createFixedConstraints(boolean pLeftBoundary)
{
return createFixedConstraints(pLeftBoundary, 1);
}
/**
* Create fixed both side constraints
* @param pLeftBoundary
* @param pGridWidth
* @return
*/
public GridBagConstraints createFixedConstraints(boolean pLeftBoundary,
int pGridWidth) {
return createFixedConstraints(pLeftBoundary, pGridWidth, 1);
}
/**
* Create fixed both side constraints
* @param pLeftBoundary boolean
* @param pGgridWidth int
* @param pGridHeight int
* @return GridBagConstraints
*/
public GridBagConstraints createFixedConstraints(boolean pLeftBoundary,
int pGridWidth, int pGridHeight) {GridBagConstraints lGridBagConstraints = new GridBagConstraints(row,column, pGridWidth, pGridHeight, 0, 0, GridBagConstraints.CENTER,GridBagConstraints.HORIZONTAL, pLeftBoundary==true? new Insets(1,0, 1, 2):new Insets(1, 12, 1, 2), 0, 0);
column+=pGridWidth;
return lGridBagConstraints;
}
/**
* Create fixed both side constraints
* @return GridBagConstraints
*/
public GridBagConstraints createFixedConstraints() {
return createFixedConstraints( 1);
}
/**
* Create fixed both side constraints
* @param pGridWidth int
* @return GridBagConstraints
*/
public GridBagConstraints createFixedConstraints(int pGridWidth) {
return  createFixedConstraints(pGridWidth, 1);
}
/*
* Create fixed both side constraints
* @param pGridWidth int
* @param pGridHeight int
* @return GridBagConstraints
*/
public GridBagConstraints createFixedConstraints(int pGridWidth,int pGridHeight) {
GridBagConstraints lGridBagConstraints = newGridBagConstraints(column, row, pGridWidth, pGridHeight, 0, 0,
GridBagConstraints.CENTER,
GridBagConstraints.HORIZONTAL,
new Insets(1, 12, 1, 2), 0, 0);
column+=pGridWidth;
return lGridBagConstraints;
}
/**
* Create horizontal glue constraints
* @return GridBagConstraints
*/
public GridBagConstraints createHorzGlueConstraints() {
return createHorzGlueConstraints(1);
}
/**
* Create horizontal glue constraints
* @param pGridWidth int
* @return GridBagConstraints
*/
public GridBagConstraints createHorzGlueConstraints(int pGridWidth) {
return createHorzGlueConstraints(pGridWidth, 1);
}
/**
* Create horizontal glue constraints
* @param pGridWidth int
* @param pGridHeight int
* @return GridBagConstraints
*/
public GridBagConstraints createHorzGlueConstraints(int pGridWidth,
int pGridHeight) {
return createHorzGlueConstraints(pGridWidth, pGridHeight, 1.0);
}
/**
* Create horizontal glue constraints
* @param pGridWidth int
* @param pGridHeight int
* @param pWeightX double
* @return GridBagConstraints
*/
public GridBagConstraints createHorzGlueConstraints(int pGridWidth,
int pGridHeight, double pWeightX) {
GridBagConstraints lGridBagConstraints = newGridBagConstraints(column, row, pGridWidth, pGridHeight, pWeightX,0.0, GridBagConstraints.CENTER, GridBagConstraints.HORIZONTAL,new Insets(1, 0, 1, 0), 0, 0);
column+=pGridWidth;
return lGridBagConstraints;
}