由于经常有人用本人电脑，一些重要的机密文件不免被人看见，所以自己写了小的加密文件数据的小工具。此加密工具采用的是最简单的加密方法：把数据分别异或得出加密后的文件；

操作步骤：

import java.awt.BorderLayout;
import java.awt.Font;
import java.awt. event .ActionEvent;
import java.awt. event .ActionListener;
import java.awt. event .ItemEvent;
import java.awt. event .ItemListener;
import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;



import javax.swing. * ;

public   class  ToolsTakePassword extends JFrame  ... {
    private static final long serialVersionUID = 1L;
    private JFileChooser jf;
    private JMenuBar jmb;
    private JMenu file;
    private JMenuItem open;
    private JMenuItem save;
    private JMenuItem exit;
    private JTextArea text;
    private JScrollPane jsp;
    private JPanel p;
    private JButton takepassword;
    private JCheckBox override;
    private JLabel intru;
    private JLabel currentfile;
    private JLabel currentfilename;
    private Font ft;
    private boolean flag = true;
    private File filesave = null;
    private File newfilesave = null;
    private JTextField codenum;
    private JProgressBar jbr;
    private int code;
    private JButton refresh;
    private JLabel inputcode;
    private JLabel temp0;
    private JLabel temp1;


    public ToolsTakePassword() ...{
        super("--文件加密器--    作者:sharpyuce.");
        jf = new JFileChooser();
        jmb = new JMenuBar();
        file = new JMenu("File");
        open = new JMenuItem("Open");
        save = new JMenuItem("Save");
        exit = new JMenuItem("Exit");
        text = new JTextArea();
        jsp = new JScrollPane(text);
        p = new JPanel();
        codenum = new JTextField(5);
        codenum.setText("50");
        refresh = new JButton("刷新");
        takepassword = new JButton("加 密");
        override = new JCheckBox();
        intru = new JLabel("是否覆盖原文件");
        currentfile = new JLabel("当前文件：");
        currentfilename = new JLabel("");
        temp0 = new JLabel("                 ");
        temp1 = new JLabel("                ");
        inputcode = new JLabel("输入加密码（输入一个整数值）：");
        
        this.init();
        this.setSize(800, 600);
        this.setVisible(true);
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }

    @SuppressWarnings("unused")
    private void init() ...{
        open.addActionListener(new ActionListener() ...{
            public void actionPerformed(ActionEvent e) ...{
                text.setText("");
                new Open().start();
            }
        });
        file.add(open);
        file.add(save);
        exit.addActionListener(new ActionListener()...{
            public void actionPerformed(ActionEvent e) ...{
                System.exit(0);
            }
            
        });
        file.add(exit);
        jmb.add(file);
        this.add(jmb, BorderLayout.NORTH);
        this.add(jsp, BorderLayout.CENTER);
        takepassword.addActionListener(new ActionListener() ...{
            public void actionPerformed(ActionEvent e) ...{
                new TakePassWord().start();
            }
        });
        p.add(inputcode);
        p.add(codenum);
        p.add(temp0);
        refresh.addActionListener(new ActionListener()...{
            public void actionPerformed(ActionEvent e) ...{
                text.setText("");
                new Refresh().start();
            }    
        });
        p.add(refresh);
        p.add(temp1);
        p.add(takepassword);
        override.addItemListener(new ItemListener()...{
            public void itemStateChanged(ItemEvent e) ...{
                flag =!flag;
            }
            
        });
        p.add(override);
        p.add(intru);
        p.add(currentfile);
        p.add(currentfilename);
        this.add(p, BorderLayout.SOUTH);
        refresh.setFont(ft);
        takepassword.setFont(ft);
        intru.setFont(ft);
        file.setFont(ft);
        save.setFont(ft);
        open.setFont(ft);
        exit.setFont(ft);
        currentfile.setFont(ft);
        currentfilename.setFont(ft);
        inputcode.setFont(ft);
    }
    
    class Open extends Thread...{
        public void run()...{
            jf.showOpenDialog(null);
            filesave = jf.getSelectedFile();
            currentfilename.setText(filesave.getAbsolutePath());
            InputStream fis = null;
            byte[] buff = new byte[1024];
            try ...{
                fis=new FileInputStream(filesave);
                while (fis.available() > 0) ...{
                    int len = fis.read(buff);
                    String s = new String(buff, 0, len);
                    text.append(s);
                }
            } catch (IOException e1) ...{
                e1.printStackTrace();
            } finally ...{
                if (fis != null) ...{
                    try ...{
                        fis.close();
                    } catch (IOException e1) ...{
                        e1.printStackTrace();
                    }
                }
            }
        }
    }

    class TakePassWord extends Thread...{
        public void run()...{
            code = Integer.parseInt(codenum.getText().trim());
            String s = text.getText();
            String[] ss = s.split(" ");
            FileOutputStream fr = null;
            if(flag)...{
                jf.showSaveDialog(null);
                newfilesave = jf.getSelectedFile();
                currentfilename.setText(newfilesave.getAbsolutePath());
            }
            try ...{
                if (flag) ...{
                    fr = new FileOutputStream(newfilesave);
                    filesave = newfilesave;
                } else ...{
                    fr = new FileOutputStream(filesave);
                    currentfilename.setText(filesave.getAbsolutePath());
                }
                for (String t : ss) ...{
                    byte[] buff = t.getBytes();
                    String n = " ";
                    for (int i = 0; i < buff.length; i++) ...{
                        fr.write(buff[i] ^ code);
                    }
                    fr.write(n.getBytes());
                }
            } catch (IOException e1) ...{
                e1.printStackTrace();
            } finally ...{
                if (fr != null) ...{
                    try ...{
                        fr.close();
                    } catch (IOException e1) ...{
                        e1.printStackTrace();
                    }
                }
            }
        }
    }
    
    class Refresh extends Thread...{
        public void run()...{
            InputStream fis = null;
            byte[] buff = new byte[1024];
            try ...{
                fis=new FileInputStream(filesave);
                while (fis.available() > 0) ...{
                    int len = fis.read(buff);
                    String s = new String(buff, 0, len);
                    text.append(s);
                }
            } catch (IOException e1) ...{
                e1.printStackTrace();
            } finally ...{
                if (fis != null) ...{
                    try ...{
                        fis.close();
                    } catch (IOException e1) ...{
                        e1.printStackTrace();
                    }
                }
            }
        }
    }
    public static void main(String[] args) ...{
        new ToolsTakePassword();
    }

}

如果想要生成EXE文件：先下载jsmooth，使用这个工具可 制作exe程序

Skeleton Chooser下拉框中选择Windowed Wrapper Skeleton Properties ： 在launch java app in the exe process 选项打勾 4. 点击Executable, 这一步是设置生成的exe文件的属性，包括名字，图标，路径 5. 设置完成后，继续下一选项，Application.Main class ： 主运行类，有main()方法的类 Embedded jar : 就是选择你要制作成EXE文件的jar 5． 其他的选项如果不需要可不必设置，最后单击project下的compile 就OK了 , 可以在装有jre的机器上直接运行。