【Java】Swing+IO流实现一个简单的文件加密程序（较完整版）

留着参考

beans

package com.my.bean;

import java.io.Serializable;

public class EncryptedFile implements Serializable {
    private String filePath;
    private String keyFullName;

    public EncryptedFile() {
    }

    public String getFilePath() {
        return filePath;
    }

    public void setFilePath(String filePath) {
        this.filePath = filePath;
    }

    public String getKeyFullName() {
        return keyFullName;
    }

    public void setKeyFullName(String keyFullName) {
        this.keyFullName = keyFullName;
    }

    @Override
    public String toString() {
        return "EncryptedFile{" +
                "filePath='" + filePath + '\'' +
                ", keyFullName='" + keyFullName + '\'' +
                '}';
    }
}

package com.my.bean;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

public class User implements Serializable {
    private String username;
    private String password;
    private List<EncryptedFile> encryptedFileList = new ArrayList<>();

    public User() {
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public List<EncryptedFile> getEncryptedFileList() {
        return encryptedFileList;
    }

    public void setEncryptedFileList(List<EncryptedFile> encryptedFileList) {
        this.encryptedFileList = encryptedFileList;
    }
}

service

package com.my.service;

import com.my.bean.User;

import java.io.*;

public class EncryptService {
    private String username;
    private static String DEFAULT_KEY_URL = ".//user//";

    private int key[] = new int[128];

    public EncryptService(User user) {
        username = user.getUsername();
    }

    public void readKey(String keyFullName) {
        File keyFile = new File(DEFAULT_KEY_URL + username + "//" + keyFullName);
        FileInputStream localKey = null;
        try {
            localKey = new FileInputStream(keyFile);
            for (int i = 0; i < 128; ++i) {
                key[i] = localKey.read();
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (localKey != null) {
                try {
                    localKey.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }

    public void makeKey(String keyName) {
        FileOutputStream fos = null;
        try {
            File keyFile = new File(DEFAULT_KEY_URL + username + "//" + keyName + ".key");
            fos = new FileOutputStream(keyFile);
            for (int i = 0; i < 128; ++i) {
                fos.write((int) (Math.random() * 128));
            }
            readKey(keyName + ".key");
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (fos != null) {
                try {
                    fos.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }

    public void encryptFile(String filePath, String keyFullName) {
        readKey(keyFullName);
        FileInputStream in = null;
        FileOutputStream out = null;
        File inFile = new File(filePath);
        File outFile = new File(inFile.getParent() + "//TEMP_FILE");
        try {
            in = new FileInputStream(inFile);
            out = new FileOutputStream(outFile);

            int length = in.available();
            for (int i = 0; i < length; ++i) {
                out.write(in.read() + key[i % 128]);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (in != null) {
                try {
                    in.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (out != null) {
                try {
                    out.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        inFile.delete();
        outFile.renameTo(inFile);
    }

    public void decryptFile(String filePath, String keyFullName) {
        readKey(keyFullName);
        FileInputStream in = null;
        FileOutputStream out = null;
        File inFile = new File(filePath);
        File outFile = new File(inFile.getParent() + "//TEMP_FILE");
        try {
            in = new FileInputStream(inFile);
            out = new FileOutputStream(outFile);

            int length = in.available();
            for (int i = 0; i < length; ++i) {
                out.write(in.read() - key[i % 128]);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (in != null) {
                try {
                    in.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (out != null) {
                try {
                    out.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        inFile.delete();
        outFile.renameTo(inFile);
    }
}

class EncryptServiceTest {
    public static void main(String[] args) {
        // 在完整程序中用户信息由Main界面提供
        User user = new User();
        user.setUsername("xkfx");
        EncryptService encryptService = new EncryptService(user);
        encryptService.encryptFile(".//hi.txt", "main.key");
        encryptService.decryptFile(".//hi.txt", "main.key");
    }
}

package com.my.service;

import com.my.bean.EncryptedFile;
import com.my.bean.User;

import java.io.*;
import java.util.List;

public class PersistenceService {
    private static String DEFAULT_DATA_URL = ".//conf//";
    String username;
    public PersistenceService(String username) {
        this.username = username;
    }

    public void loadData(User user) {
        BufferedReader br;
        try {
            br = new BufferedReader(new FileReader(new File(DEFAULT_DATA_URL + username + ".user")));
            while (br.ready()) {
                EncryptedFile file = new EncryptedFile();
                file.setFilePath(br.readLine());
                file.setKeyFullName(br.readLine());
                user.getEncryptedFileList().add(file);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public void saveData(User user) {
        PrintWriter pw = null;
        try {
            pw = new PrintWriter(new FileWriter(new File(DEFAULT_DATA_URL + username + ".user")));
            for (EncryptedFile file : user.getEncryptedFileList()) {
                pw.println(file.getFilePath());
                pw.println(file.getKeyFullName());
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                pw.close();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }
}

class PersistenceServiceTest {
    public static void main(String[] args) {
        User user = new User();
        user.setUsername("zzz");
        EncryptedFile file1 = new EncryptedFile();
        file1.setFilePath("aaaa");
        file1.setKeyFullName("bbbbbbbbbb");
        EncryptedFile file2 = new EncryptedFile();
        file2.setFilePath("xxxx");
        file2.setKeyFullName("qqqqqqq");
        user.getEncryptedFileList().add(file1);
        user.getEncryptedFileList().add(file2);

        PersistenceService persistenceService = new PersistenceService(user.getUsername());
        // 存进文件，默认为 conf/username.user
        persistenceService.saveData(user);
        // 取出来并输出
        persistenceService.loadData(user);
        for (EncryptedFile file : user.getEncryptedFileList()) {
            System.out.println(file);
        }
    }
}

UI

package com.my.ui;

import com.my.bean.EncryptedFile;
import com.my.bean.User;

import javax.swing.*;
import java.awt.*;

public class EncryptedFileManagement extends JFrame {
    private User user;
    private Main mainFrame;
    public EncryptedFileManagement(User user) {
        this.user = user;
        setTitle("加密文件管理");
        setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        setLocationRelativeTo(null);
        setResizable(false);
        setLayout(new BorderLayout());
        updateFrame();
    }

    public void setMainFrame(Main mainFrame) {
        this.mainFrame = mainFrame;
        // 传递主界面的一个引用，以便监控子窗口的Action
    }

    public void addEncryptedFile(String filePath, String keyFullName) {
        EncryptedFile encryptedFile = new EncryptedFile();
        user.getEncryptedFileList().add(encryptedFile);
        encryptedFile.setFilePath(filePath);
        encryptedFile.setKeyFullName(keyFullName);

        updateFrame();
    }

    public boolean removeEncryptedFile(String filePath, String keyFullName) {
        int listSize = user.getEncryptedFileList().size();
        for (int i = 0; i != listSize; ++i) {
            EncryptedFile file = user.getEncryptedFileList().get(i);
            if (file.getFilePath().equals(filePath) && file.getKeyFullName().equals(keyFullName)) {
                user.getEncryptedFileList().remove(i);
                updateFrame();
                return true;
            }
        }
        return false;
    }

    JPanel listPanel = new JPanel();
    public void updateFrame() {
        listPanel.removeAll(); // 必须调用这个方法，否则视图显示将和真实情况不匹配
        listPanel.setLayout(new GridLayout(user.getEncryptedFileList().size(), 2));
        for (EncryptedFile file : user.getEncryptedFileList()) {
            JButton buttonFilePath = new JButton("■" + file.getFilePath());
            JButton buttonKeyFullPath = new JButton("▲" + file.getKeyFullName());
            listPanel.add(buttonFilePath);
            listPanel.add(buttonKeyFullPath);
            // 注册事件监听
            buttonFilePath.addActionListener(mainFrame);
            buttonKeyFullPath.addActionListener(mainFrame);
            buttonFilePath.setFocusPainted(false);
            buttonKeyFullPath.setFocusPainted(false);
        };
        setSize(482, user.getEncryptedFileList().size()*44 + 57);
        add(listPanel, BorderLayout.CENTER);
    }
}

class EncryptedFileManagementTest {
    public static void main(String[] args) {
        // 实际中是代理Main中的User
        User user = new User();
        user.setUsername("xkfx");

        EncryptedFileManagement frame = new EncryptedFileManagement(user);
        Main main = new Main(user);
        main.setVisible(true);
        frame.setMainFrame(main);
        for (int i = 0; i != 5; ++i) {
            frame.addEncryptedFile("D:\\workspace\\untitled1\\hi.txt", i + "main.key");
        }
        frame.setVisible(true);
    }
}

package com.my.ui;

import com.my.bean.User;
import com.my.service.EncryptService;
import com.my.service.PersistenceService;
import com.my.util.Iconst;

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;

public class Main extends JFrame implements ActionListener {
    // 保存服务对象
    private User user;
    private EncryptService encryptService;
    PersistenceService persistenceService;
    private EncryptedFileManagement encryptedFileManagement;
    // 窗体默认大小
    private static final int DEFAULT_WIDTH = 416;
    private static final int DEFAULT_HEIGHT = 145;
    // 全局组件
    private JFileChooser fileChooser;
    private JButton buttonEncrypt;
    private JButton buttonDecrypt;
    private JButton buttonMakeNewKey;
    private JButton buttonEncryptedFileManagement;
    private JButton buttonExit;
    private JTextField textFilePath;
    private JTextField textKeyName;
    // 保存当前文件、密匙路径
    private String filePath;
    private String keyPath;

    public void setFilePath(String filePath) {
        this.filePath = filePath;
    }

    public void setKeyPath(String keyPath) {
        this.keyPath = keyPath;
    }

    // 窗体初始化
    public Main(User user) {
        // 初始化用户和服务
        this.user = user;
        encryptService = new EncryptService(this.user);
        persistenceService = new PersistenceService(this.user.getUsername());
        persistenceService.loadData(this.user);
        encryptedFileManagement = new EncryptedFileManagement(this.user);
        encryptedFileManagement.setMainFrame(this);
        // 初始化界面
        setTitle("用户ID：" + user.getUsername());
        setDefaultCloseOperation(0);
        setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
        setResizable(false);
        setLocationRelativeTo(null);

        JPanel bigPanel = new JPanel();
        // 布置主要界面
        textFilePath = new JTextField();
        textKeyName = new JTextField();
        JButton buttonChooseFile = new JButton(Iconst.CHOOSE_FILE);
        JButton buttonChooseKey = new JButton(Iconst.CHOOSE_KEY);

        textFilePath.setEditable(false);
        textKeyName.setEditable(false);
        buttonChooseKey.setFocusPainted(false);
        buttonChooseFile.setFocusPainted(false);

        bigPanel.setLayout(new GridLayout(2, 3));
        bigPanel.add(new JLabel("文件路径"));
        bigPanel.add(textFilePath);
        bigPanel.add(buttonChooseFile);
        bigPanel.add(new JLabel("密匙名称"));
        bigPanel.add(textKeyName);
        bigPanel.add(buttonChooseKey);

        JPanel buttonPanel = new JPanel();
        // 布置按钮界面
        buttonEncrypt = new JButton(Iconst.ENCRYPT);
        buttonDecrypt = new JButton(Iconst.DECRYPT);
        buttonMakeNewKey = new JButton(Iconst.CREATE_NEW_KEY);
        buttonEncryptedFileManagement = new JButton(Iconst.ENCRYPTED_FILE_MANAGEMENT);
        buttonExit = new JButton(Iconst.EXIT);

        buttonEncrypt.setFocusPainted(false);
        buttonDecrypt.setFocusPainted(false);
        buttonMakeNewKey.setFocusPainted(false);
        buttonEncryptedFileManagement.setFocusPainted(false);
        buttonExit.setFocusPainted(false);

        buttonPanel.setLayout(new FlowLayout());
        buttonPanel.add(buttonEncrypt);
        buttonPanel.add(buttonDecrypt);
        buttonPanel.add(buttonMakeNewKey);
        buttonPanel.add(buttonEncryptedFileManagement);
        buttonPanel.add(buttonExit);

        // 布置窗体
        setLayout(new BorderLayout());
        add(bigPanel, BorderLayout.CENTER);
        add(buttonPanel, BorderLayout.SOUTH);

        // 注册事件监听
        buttonChooseFile.addActionListener(this);
        buttonChooseKey.addActionListener(this);
        buttonMakeNewKey.addActionListener(this);
        buttonEncrypt.addActionListener(this);
        buttonDecrypt.addActionListener(this);
        buttonEncryptedFileManagement.addActionListener(this);
        buttonExit.addActionListener(this);

        // 创建文件选择器
        fileChooser = new JFileChooser();
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        if (e.getActionCommand().charAt(0) == "■".charAt(0)) {
            String filePath = e.getActionCommand().substring(1, e.getActionCommand().length());
            setFilePath(filePath);
            textFilePath.setText(filePath);
        }
        if (e.getActionCommand().charAt(0) == "▲".charAt(0)) {
            String keyFullName = e.getActionCommand().substring(1, e.getActionCommand().length());
            setKeyPath(".//user//" + user.getUsername() + "//" + keyFullName);
            textKeyName.setText(keyFullName);
        }
        if (e.getActionCommand().equals(Iconst.CHOOSE_FILE)) {
            fileChooser.setCurrentDirectory(new File("."));
            int result = fileChooser.showOpenDialog(null);
            if (result == JFileChooser.APPROVE_OPTION) {
                filePath = fileChooser.getSelectedFile().getPath();
                textFilePath.setText(filePath);
            }
        }
        if (e.getActionCommand().equals(Iconst.CHOOSE_KEY)) {
            fileChooser.setCurrentDirectory(new File(".//user//" + user.getUsername()));
            int result = fileChooser.showOpenDialog(null);
            if (result == JFileChooser.APPROVE_OPTION) {
                keyPath = fileChooser.getSelectedFile().getPath();
                textKeyName.setText(new File(keyPath).getName());
            }
        }
        if (e.getActionCommand().equals(Iconst.ENCRYPT)) {
            if (filePath != null && !"".equals(filePath) && textKeyName.getText() != null && !"".equals(textKeyName.getText())) {
                encryptService.encryptFile(filePath, textKeyName.getText());
                encryptedFileManagement.addEncryptedFile(filePath, textKeyName.getText());
                JOptionPane.showMessageDialog(this, "加密成功");
            } else {
                JOptionPane.showMessageDialog(this, "文件路径、密匙名称不能为空！");
            }
        }
        if (e.getActionCommand().equals(Iconst.DECRYPT)) {
            if (filePath != null && !"".equals(filePath) && textKeyName.getText() != null && !"".equals(textKeyName.getText()) ) {
                if (encryptedFileManagement.removeEncryptedFile(filePath, textKeyName.getText())) {
                    encryptService.decryptFile(filePath, textKeyName.getText());
                    JOptionPane.showMessageDialog(this, "还原成功");
                } else {
                    JOptionPane.showMessageDialog(this, "该文件未被加密或密匙不匹配");
                }
            } else {
                JOptionPane.showMessageDialog(this, "文件路径、密匙名称不能为空！");
            }
        }
        if (e.getActionCommand().equals(Iconst.CREATE_NEW_KEY)) {
            String keyName = JOptionPane.showInputDialog(this, "请输入新密匙的名称：");
            if (keyName != null && !"".equals(keyName)) {
                encryptService.makeKey(keyName);
                JOptionPane.showMessageDialog(this, "成功创建新的密匙");
            }
            // 更新当前密匙路径
            setKeyPath(".//user//" + user.getUsername() + "//" + keyName + ".key");
            textKeyName.setText(keyName + ".key");
        }
        if (e.getActionCommand().equals(Iconst.ENCRYPTED_FILE_MANAGEMENT)) {
            if (user.getEncryptedFileList().size() == 0) {
                JOptionPane.showMessageDialog(this, "加密文件为空");
            } else {
                encryptedFileManagement.setVisible(true);
            }
        }
        if (e.getActionCommand().equals(Iconst.EXIT)) {
            if (JOptionPane.showConfirmDialog(this,"确定退出？") == 0) {
                persistenceService.saveData(user);
                this.dispose();
                System.exit(0);
            }
        }
    }
}

class MainTest {
    public static void main(String[] args) {
        User user = new User();
        user.setUsername("xkfx");
        EventQueue.invokeLater(() -> {
            JFrame frame = new Main(user);
            frame.setVisible(true);
        });
    }
}

工具类

package com.my.util;

/**
 * 常量定义
 */
public interface Iconst {
    public static final String LOGIN = "登陆";
    public static final String REGISTER = "注册";
    public static final String CHOOSE_FILE = "选择文件";
    public static final String CHOOSE_KEY = "选择密匙";
    public static final String ENCRYPT = "加密";
    public static final String DECRYPT = "还原";
    public static final String CREATE_NEW_KEY = "生成新的密匙";
    public static final String ENCRYPTED_FILE_MANAGEMENT = "管理文件";
    public static final String EXIT = "退出";
}

由于电脑原因，源代码的编码可能会有一些问题：http://pan.baidu.com/s/1o8hsWd0