import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.io.*;
import java.security.*;
import javax.crypto.*;
import javax.crypto.spec.*;
/**
文件名：FileEncrypter.java
说明：文件加密
加密方法：三重DES加密
加密过程：对选中的文件加密后在同文件夹下生成一个增加了".tdes"
扩展名的加密文件
解密过程：对选中的加密文件（必须有".tdes"扩展名）进行解密
*/
public class FileEncrypter extends JFrame{
public static void main(String args[]) {
FileEncrypter fe = new FileEncrypter();
fe.show();
}
FileEncrypter(){
this.setSize(WIDTH,HEIGHT);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setResizable(false);
Toolkit tk = Toolkit.getDefaultToolkit();
Dimension screenSize = tk.getScreenSize();
this.setTitle("文件加密器(TriDES)");
Container c = this.getContentPane();
c.setLayout( new FlowLayout());
final FilePanel fp = new FilePanel("文件选择");
c.add(fp);
final KeyPanel pp = new KeyPanel("密码");
c.add(pp);
JButton jbE = new JButton("加密");
c.add(jbE);
jbE.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent event){
File file = new File(fp.getFileName());
if (file.exists())
encrypt(file.getAbsoluteFile(),pp.getKey());
else
JOptionPane.showMessageDialog(
null,"请选择文件！","提示",JOptionPane.OK_OPTION);
});
JButton jbD = new JButton("解密");
c.add(jbD);
jbD.addActionListener(new ActionListener(){
decrypt(file.getAbsoluteFile(),pp.getKey());
加密函数
输入：
其中：
输出：
对输入的文件加密后,保存到同一文件夹下增加了".tdes"扩展名的文件中.
private void encrypt(File fileIn,String sKey){
try{
FileInputStream fis = new FileInputStream(fileIn);
byte[] bytIn = new byte[(int)fileIn.length()];
for(int i = 0;iFILEIN.LENGTH();I++){
bytIn[i] = (byte)fis.read();
//加密
byte[] bytOut = encryptByDES(encryptByDES(
String fileOut = fileIn.getPath() + ".tdes";
FileOutputStream fos = new FileOutputStream(fileOut);
for(int i = 0;iBYTOUT.LENGTH;I++){
fos.write((int)bytOut[i]);
fos.close();
this,"加密成功！","提示",JOptionPane.OK_OPTION);
}else
}catch(Exception e){
e.printStackTrace();
解密函数
对输入的文件解密后,保存到用户指定的文件中.
private void decrypt(File fileIn,String sKey){
String strPath = fileIn.getPath();
else{
this,"不是合法的加密文件！","提示",JOptionPane.OK_OPTION);
return;
JFileChooser chooser = new JFileChooser();
chooser.setCurrentDirectory(new File("."));
chooser.setSelectedFile(new File(strPath));
//用户指定要保存的文件
int ret = chooser.showSaveDialog(this);
if(ret==JFileChooser.APPROVE_OPTION){
//解密
byte[] bytOut = decryptByDES(decryptByDES(
File fileOut = chooser.getSelectedFile();
fileOut.createNewFile();
this,"解密成功！","提示",JOptionPane.OK_OPTION);
this,"解密失败,请核对密码！","提示",JOptionPane.OK_OPTION);
用DES方法加密输入的字节
private byte[] encryptByDES(byte[] bytP,byte[] bytKey) throws Exception{
DESKeySpec desKS = new DESKeySpec(bytKey);
SecretKeyFactory skf = SecretKeyFactory.getInstance("DES");
SecretKey sk = skf.generateSecret(desKS);
Cipher cip = Cipher.getInstance("DES");
cip.init(Cipher.ENCRYPT_MODE,sk);
return cip.doFinal(bytP);
用DES方法解密输入的字节
private byte[] decryptByDES(byte[] bytE,byte[] bytKey) throws Exception{
cip.init(Cipher.DECRYPT_MODE,sk);
return cip.doFinal(bytE);
输入密码的字符形式,返回字节数组形式.
private byte[] getKeyByStr(String str){
for(int i=0;iSTR.LENGTH()
Integer itg =
bRet[i] = itg.byteValue();
return bRet;
输入：0-F
private int getChrInt(char chr){
int iRet=0;
if(chr=="0".charAt(0)) iRet = 0;
if(chr=="1".charAt(0)) iRet = 1;
if(chr=="A".charAt(0)) iRet = 10;
if(chr=="B".charAt(0)) iRet = 11;
return iRet;
文件选择组件.
class FilePanel extends JPanel{
FilePanel(String str){
JLabel label = new JLabel(str);
JButton chooseButton = new JButton("浏览...");
this.add(label);
this.add(fileText);
this.add(chooseButton);
clickAction ca = new clickAction(this);
chooseButton.addActionListener(ca);
public String getFileName(){
JTextField jtf = (JTextField)this.getComponent(1);
return jtf.getText();
private class clickAction implements ActionListener{
clickAction(Component c){
cmpt = c;
int ret = chooser.showOpenDialog(cmpt);
JPanel jp = (JPanel)cmpt;
JTextField jtf = (JTextField)jp.getComponent(1);
jtf.setText(chooser.getSelectedFile().getPath());
private Component cmpt;
密码生成组件.
class KeyPanel extends JPanel{
KeyPanel(String str){
JButton chooseButton = new JButton("随机产生");
public String getKey(){
KeyGenerator kg = KeyGenerator.getInstance("DES");
Key ke = kg.generateKey();
byte[] bytK1 = ke.getEncoded();
ke = kg.generateKey();
private String getByteStr(byte[] byt){
String strRet = "";
for(int i=0;iBYT.LENGTH;I++){
//System.out.println(byt[i]);
return strRet;
private String getHexValue(int s){
String sRet=null;
switch (s){
case 0: sRet = "0";break;
case 1: sRet = "1";break;
case 10: sRet = "A";break;
case 11: sRet = "B";break;
return sRet;
使用DocumentFilter
import java.awt.EventQueue;
import java.awt.GridBagLayout;
import java.awt.Toolkit;
import javax.print.attribute.AttributeSet;
import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.text.AbstractDocument;
import javax.swing.text.BadLocationException;
import javax.swing.text.DocumentFilter;
import javax.swing.text.DocumentFilter.FilterBypass;
public class FilterTest {
public static void main(String[] args) {
new FilterTest();
public FilterTest() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
JTextField field = new JTextField(10);
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new GridBagLayout());
frame.add(field);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
public class SizeFilter extends DocumentFilter {
private int maxCharacters;
public SizeFilter(int maxChars) {
maxCharacters = maxChars;
public void insertString(FilterBypass fb, int offs, String str, AttributeSet a)
throws BadLocationException {
if ((fb.getDocument().getLength() + str.length()) = maxCharacters) {
super.insertString(fb, offs, str, a);
} else {
Toolkit.getDefaultToolkit().beep();
public void replace(FilterBypass fb, int offs, int length, String str, AttributeSet a)
if ((fb.getDocument().getLength() + str.length()
- length) = maxCharacters) {
super.replace(fb, offs, length, str, a);
正则表达式,是最好的方式.
下面这个正是判断必须同时包含数字和字母的.长度单独检测.
public static void main(String[] argv) {
String name1 = "aaaaaaaaaaa";
System.out.println(name1.matches(reg));
以上就是土嘎嘎小编为大家整理的java限制密码长度代码相关主题介绍,如果您觉得小编更新的文章只要能对粉丝们有用,就是我们最大的鼓励和动力,不要忘记讲本站分享给您身边的朋友哦！！