java 判断两个文件是否相同

更新时间：2021-11-03 10:14:04

使用Java 如何判断两个文件是否相同呢？

我的做法是

（1）先比较两个文件内容的长度；

（2）在长度相同的情况下，再比较两个文件的MD5值。

【create md5】按钮用于生成source file的文件内容长度和MD5值。

运行主类：CheckSameApp

Java代码  
package com.hw.main;  
  
import java.awt.BorderLayout;  
import java.awt.Container;  
import java.awt.Dimension;  
import java.awt.GridBagConstraints;  
import java.awt.GridBagLayout;  
import java.awt.Insets;  
import java.awt.Toolkit;  
import java.awt.event.ActionEvent;  
import java.awt.event.ActionListener;  
import java.io.File;  
  
import javax.swing.JButton;  
import javax.swing.JFileChooser;  
import javax.swing.JFrame;  
import javax.swing.JLabel;  
import javax.swing.JPanel;  
import javax.swing.JTextField;  
  
import com.common.util.SystemUtil;  
import com.swing.dialog.DialogUtil;  
import com.swing.messagebox.GUIUtil23;  
  
public class CheckSameApp extends JFrame  
{  
    private static final long serialVersionUID = 1644076682819874235L;  
    private JTextField        sourceFileTF;  
    private JButton           browserSourceBtn;  
    private JTextField        targetFileTF;  
    private JButton           createmd5Button  = null;  
    private JButton           checkmd5Btn      = null;  
    private JButton           browserTargetBtn = null;  
    /*** 
     * MD5 of last file 
     */  
    private String            result           = null;  
    private long              size_of_file     = 0;  
    private JButton           compareBtn       = null;  
    private File              srcfile          = null;  
    private File              targfile         = null;  
    protected static String   MESG_DIFF        = "[failed:] they are different";  
    protected static String   MESG_SAME        = "[successfully:] they are same completely";  
  
    public static void main(String[] args)  
    {  
        CheckSameApp app = new CheckSameApp();  
        app.launchFrame();  
    }  
  
    public void launchFrame()  
    {  
        this.setTitle("Compare two files by MD5");  
        Dimension screensize = Toolkit.getDefaultToolkit().getScreenSize();  
        this.setSize(700, 200);  
        Dimension framesize = this.getSize();  
        int x = (int) screensize.getWidth() / 2 - (int) framesize.getWidth()  
            / 2;  
        int y = (int) screensize.getHeight() / 2 - (int) framesize.getHeight()  
            / 2;  
        this.setLocation(x, y);  
        Container c = this.getContentPane();  
        layout(c);  
        this.setVisible(true);  
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);  
    }  
  
    /*** 
     * setting menu 
     */  
      
  
    public void layout(Container c)  
    {  
        //        setMenu2();  
        JPanel mainPane = new JPanel();  
        GridBagLayout gridBagLayout = new GridBagLayout();  
        gridBagLayout.columnWidths = new int[]  
        { 20, 80/*between source file and text field*/, 300, 60, 0 };  
        gridBagLayout.rowHeights = new int[]  
        { 17, 0, 0, 0, 0, 0, 0, 0, 0, 25, 0, 0 };  
        gridBagLayout.columnWeights = new double[]  
        { 0.0, 0.0, 1.0, 1.0, Double.MIN_VALUE };  
        gridBagLayout.rowWeights = new double[]  
        { 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 1.0, 1.0,  
            Double.MIN_VALUE };  
  
        mainPane.setLayout(gridBagLayout);  
        JLabel ftpServerLb = new JLabel("source file");  
        GridBagConstraints gbc_setConnectionsLabel = new GridBagConstraints();  
        gbc_setConnectionsLabel.anchor = GridBagConstraints.WEST;  
        gbc_setConnectionsLabel.insets = new Insets(0, 0, 5, 5);  
        gbc_setConnectionsLabel.gridx = 1;  
        gbc_setConnectionsLabel.gridy = 1;  
        mainPane.add(ftpServerLb, gbc_setConnectionsLabel);  
        //        dialog.add(ftpserverTF);  
  
        sourceFileTF = new JTextField();  
        if (!SystemUtil.isWindows)  
        {  
            sourceFileTF.setText("/home/whuang2/bin/ab.txt");  
        }  
        else  
        {  
            sourceFileTF.setText("");  
        }  
        GridBagConstraints gbc_connectionsTF = new GridBagConstraints();  
        gbc_connectionsTF.fill = GridBagConstraints.HORIZONTAL;  
        gbc_connectionsTF.insets = new Insets(0, 0, 5, 5);  
        gbc_connectionsTF.gridx = 2;  
        gbc_connectionsTF.gridy = 1;  
        mainPane.add(sourceFileTF, gbc_connectionsTF);  
  
        browserSourceBtn = new JButton("browser source");  
        GridBagConstraints gbc_browserSourceBtn = new GridBagConstraints();  
        gbc_browserSourceBtn.fill = GridBagConstraints.EAST;  
        gbc_browserSourceBtn.insets = new Insets(0, 0, 5, 5);  
        gbc_browserSourceBtn.gridx = 3;  
        gbc_browserSourceBtn.gridy = 1;  
        mainPane.add(browserSourceBtn, gbc_browserSourceBtn);  
        browserSourceBtn.addActionListener(new ActionListener()  
        {  
            @Override  
            public void actionPerformed(ActionEvent e)  
            {  
                //                System.out.println("source");  
                boolean isSuccess = DialogUtil.browser3(sourceFileTF,  
                    JFileChooser.FILES_ONLY, CheckSameApp.this);  
                //                if (isSuccess)  
                //                {  
                //                    targetFileTF.setText(SystemUtil.getParentDir(sourceFileTF  
                //                            .getText()));  
                //                }  
            }  
        });  
  
        JPanel buttonPane = new JPanel();  
        //        buttonPane.setBackground(Color.red);  
        GridBagConstraints gbc_buttonPane = new GridBagConstraints();  
        gbc_buttonPane.fill = GridBagConstraints.HORIZONTAL;  
        gbc_buttonPane.insets = new Insets(0, 0, 5, 5);  
        gbc_buttonPane.gridx = 2;  
        gbc_buttonPane.gridy = 2;  
        mainPane.add(buttonPane, gbc_buttonPane);  
  
        createmd5Button = new JButton("create md5");  
        checkmd5Btn = new JButton("check");  
        checkmd5Btn.setEnabled(false);  
        buttonPane.add(createmd5Button);  
        buttonPane.add(checkmd5Btn);  
        createmd5Button.addActionListener(new ActionListener()  
        {  
            @Override  
            public void actionPerformed(ActionEvent e)  
            {  
                if (!validate3(true))  
                {  
                    return;  
                }  
                sourceFileTF.setEditable(false);  
                new Thread(new Runnable()  
                {  
                    @Override  
                    public void run()  
                    {  
                        createmd5Button.setEnabled(false);  
                        size_of_file = srcfile.length();  
                        result = SystemUtil.getFileMD5(srcfile);  
                        checkmd5Btn.setEnabled(true);  
                        createmd5Button.setEnabled(true);  
                    }  
                }).start();  
  
                  
            }  
        });  
  
        checkmd5Btn.addActionListener(new ActionListener()  
        {  
            @Override  
            public void actionPerformed(ActionEvent e)  
            {  
                //                if (!validate3(true))  
                //                {  
                //                    return;  
                //                }  
                long size_of_file2 = srcfile.length();  
                if (size_of_file2 != size_of_file)  
                {  
                    System.out.println("by size");  
                    GUIUtil23.errorDialog(MESG_DIFF);  
                    return;  
                }  
  
                new Thread(new Runnable()  
                {  
                    @Override  
                    public void run()  
                    {  
                        checkmd5Btn.setEnabled(false);  
                        String result2;  
                        sourceFileTF.setEditable(true);  
                        result2 = SystemUtil.getFileMD5(srcfile);  
                        boolean isSame2=isSame(result2, result);  
                        checkmd5Btn.setEnabled(true);  
                        if (isSame2)  
                        {  
                            GUIUtil23.infoDialog(MESG_SAME);  
                        }  
                        else  
                        {  
                            GUIUtil23.errorDialog(MESG_DIFF);  
                        }  
                    }  
                }).start();  
                  
            }  
        });  
  
        JLabel targetLabel = new JLabel("target file");  
        GridBagConstraints gbc_driveClassLabel = new GridBagConstraints();  
        gbc_driveClassLabel.anchor = GridBagConstraints.WEST;  
        gbc_driveClassLabel.insets = new Insets(0, 0, 5, 5);  
        gbc_driveClassLabel.gridx = 1;  
        gbc_driveClassLabel.gridy = 3;  
        mainPane.add(targetLabel, gbc_driveClassLabel);  
  
        targetFileTF = new JTextField();  
        if (!SystemUtil.isWindows)  
        {  
            targetFileTF.setText("/home/whuang2/bin/wh_dos2unix");  
        }  
        GridBagConstraints gbc_driveClassTF = new GridBagConstraints();  
        gbc_driveClassTF.insets = new Insets(0, 0, 5, 5);  
        gbc_driveClassTF.fill = GridBagConstraints.HORIZONTAL;  
        gbc_driveClassTF.gridx = 2;  
        gbc_driveClassTF.gridy = 3;  
        mainPane.add(targetFileTF, gbc_driveClassTF);  
        targetFileTF.setColumns(10);  
  
        browserTargetBtn = new JButton("browser target");  
        GridBagConstraints gbc_browserTargetBtn = new GridBagConstraints();  
        gbc_browserTargetBtn.fill = GridBagConstraints.EAST;  
        gbc_browserTargetBtn.insets = new Insets(0, 0, 5, 5);  
        gbc_browserTargetBtn.gridx = 3;  
        gbc_browserTargetBtn.gridy = 3;  
        mainPane.add(browserTargetBtn, gbc_browserTargetBtn);  
        browserTargetBtn.addActionListener(new ActionListener()  
        {  
            @Override  
            public void actionPerformed(ActionEvent e)  
            {  
                //                System.out.println("target");  
                DialogUtil.browser3(targetFileTF,  
                    JFileChooser.FILES_AND_DIRECTORIES, CheckSameApp.this);  
            }  
        });  
        compareBtn = new JButton("compare");  
        GridBagConstraints gbc_runBtn = new GridBagConstraints();  
        gbc_runBtn.fill = GridBagConstraints.EAST;  
        gbc_runBtn.insets = new Insets(0, 0, 5, 5);  
        gbc_runBtn.gridx = 4;  
        gbc_runBtn.gridy = 3;  
        mainPane.add(compareBtn, gbc_runBtn);  
  
        compareBtn.addActionListener(new ActionListener()  
        {  
  
            @Override  
            public void actionPerformed(ActionEvent e)  
            {  
                if (!validate3(false))  
                {  
                    return;  
                }  
  
                long size_of_targfile = targfile.length();  
                long size_of_srcfile = srcfile.length();  
                if (size_of_targfile != size_of_srcfile)  
                {  
                    System.out.println("by size");  
                    GUIUtil23.errorDialog(MESG_DIFF);  
                    return;  
                }  
                new Thread(new Runnable()  
                {  
                    @Override  
                    public void run()  
                    {  
                        compareBtn.setEnabled(false);  
                        String result_source = SystemUtil.getFileMD5(srcfile);  
                        String result_target;  
                        result_target = SystemUtil.getFileMD5(targfile);  
                        boolean isSame2=isSame(result_source, result_target);  
                        compareBtn.setEnabled(true);  
                        if (isSame2)  
                        {  
                            GUIUtil23.infoDialog(MESG_SAME);  
                        }  
                        else  
                        {  
                            GUIUtil23.errorDialog(MESG_DIFF);  
                        }  
  
                    }  
                }).start();  
            }  
        });  
  
        c.add(mainPane, BorderLayout.CENTER);  
        //        System.out.println(c.getLayout());  
        //new JScrollPane(text)  
    }  
  
    //    private String create_md5(String filePath)  
    //    {  
    //        try  
    //        {  
    //            return create_md5(filePath, null);  
    //        }  
    //        catch (IOException e)  
    //        {  
    //            e.printStackTrace();  
    //        }  
    //        return null;  
    //    }  
  
    /*** 
     *  
     * @param result_source : such as b79898bb7907648871745cd5422c79ce   /home/whuang2/bin/ab.txt 
     * @param result_target 
     * @return 
     */  
    private boolean isSame(String result_source, String result_target)  
    {  
        if (result_source == null || result_target == null)  
        {  
            return false;  
        }  
        return (result_source.split("[ \t]")[0].equals(result_target  
                .split("[ \t]")[0]));  
    }  
  
  
    private boolean validate3(boolean isSelf)  
    {  
        String sourceFile = sourceFileTF.getText();  
        String targetFile_dir = targetFileTF.getText();  
        if (sourceFile == null || sourceFile.equals(""))  
        {  
            GUIUtil23  
                    .warningDialog("source file can not be empty,please select again  !");  
            sourceFileTF.requestFocus();//focus  
  
            return false;  
        }  
        if (!isSelf)  
        {  
            if (targetFile_dir == null || targetFile_dir.equals(""))  
            {  
                GUIUtil23  
                        .warningDialog("target file can not be empty,please select again !");  
                targetFileTF.requestFocus();//focus  
                return false;  
            }  
        }  
        //                System.out.println("source file:" + sourceFile);  
        //                System.out.println("target file:" + targetFile_dir);  
        srcfile = new File(sourceFile);  
        if (!srcfile.exists())  
        {  
            GUIUtil23  
                    .warningDialog("source file does not exist,please select again!");  
            sourceFileTF.requestFocus();//focus  
            sourceFileTF.selectAll();  
            return false;  
        }  
        if (srcfile.exists() && srcfile.isDirectory())  
        {  
            GUIUtil23  
                    .warningDialog("source file can not be directory,please select again!");  
            sourceFileTF.requestFocus();//focus  
            sourceFileTF.selectAll();  
            return false;  
        }  
        if (!isSelf)  
        {  
            {  
                targfile = new File(targetFile_dir);  
                if (!targfile.exists())  
                {  
                    GUIUtil23  
                            .warningDialog("target file does not exist,please select again!");  
                    targetFileTF.requestFocus();//focus  
                    targetFileTF.selectAll();  
                    return false;  
                }  
                if (targfile.exists() && targfile.isDirectory())  
                {  
                    GUIUtil23  
                            .warningDialog("target file can not be directory,please select again!");  
                    targetFileTF.requestFocus();//focus  
                    targetFileTF.selectAll();  
                    return false;  
                }  
            }  
        }  
        return true;  
  
    }  
  
    //    public static void main2(String[] args)  
    //    {  
    //        String sourceFile = "/home/whuag2/workspace/io0007-find_progess/src/com/cmd/dos/hw/util/CMDUtil.java";  
    //        md5(sourceFile);  
    //    }  
  
}  

swingwork类：CheckSameSwingWorker

Java代码  
package com.hw.util;  
  
import java.io.BufferedReader;  
import java.io.IOException;  
import java.io.InputStreamReader;  
import java.util.List;  
  
import javax.swing.SwingWorker;  
  
import com.common.util.MyProcess;  
  
public class CheckSameSwingWorker extends SwingWorker<Boolean, Character>  
{  
    private BufferedReader br_right       = null;  
    private BufferedReader br_error       = null;  
    private MyProcess      myprocess      = null;  
    private char           word           = ' ';  
    private int            tmp            = 0;  
    private boolean        isPrintVerbose = false;  
    private StringBuffer   stringbuf      = new StringBuffer();  
  
    public CheckSameSwingWorker(MyProcess myprocess, BufferedReader br)  
    {  
        this.br_right = br;  
        this.myprocess = myprocess;  
  
    }  
  
    public CheckSameSwingWorker(MyProcess myprocess)  
    {  
        this.myprocess = myprocess;  
        br_right = new BufferedReader(new InputStreamReader(  
            myprocess.getInputStream()), 4096);  
        br_error = new BufferedReader(new InputStreamReader(  
            myprocess.getErrorStream()), 4096);  
    }  
  
    @Override  
    protected Boolean doInBackground() throws Exception  
    {  
        while ((tmp = br_right.read()) != -1)  
        {  
            word = (char) tmp;  
            publish(word);  
        }  
        while ((tmp = br_error.read()) != -1)  
        {  
            word = (char) tmp;  
            publish(word);  
        }  
        if (isPrintVerbose)  
        {  
            System.out.println("doInBackground() over");  
        }  
        return true;  
    }  
  
    @Override  
    protected void process(List<Character> chunks)  
    {  
        for (char temp : chunks)  
        {  
            {  
//                System.out.print(temp);  
                this.stringbuf.append(temp);  
            }  
        }  
    }  
  
    public StringBuffer getStringbuf()  
    {  
        return stringbuf;  
    }  
  
    /*** 
     * main thread can't execute next command(below waitFor())  
     * until done() is executed 
     */  
    @Override  
    protected void done()  
    {  
        if (isPrintVerbose)  
        {  
            System.out.println("done() is finish");  
        }  
        try  
        {  
            br_right.close();  
        }  
        catch (IOException e)  
        {  
            e.printStackTrace();  
        }  
        this.myprocess.stopLoop();  
    }  
  
}  

上一篇 : ：使用spring aop aspect为什么没有被调用下一篇 : postgreSQL 常用命令

java 判断两个文件是否相同

相关阅读

推荐文章