Question

我正在开发一个项目，我必须从文件夹生成多个文件的SHA-1值。我有一个java函数，可以给我一个文件的值。我想使用Jfilechooser一次选择多个文件并生成SHA-1哈希值并将其存储在其他目录中的文本文件中。我正在使用Netbeans。请帮我解决这个问题。我发布的代码是仅为一个文件生成SHA-1值。

import java.io.FileInputStream;
import java.security.MessageDigest;

public class TestCheckSum {

public static void main(String args[]) throws Exception {

String datafile = "/Users/Samip/Desktop/untitled.txt";

MessageDigest md = MessageDigest.getInstance("SHA1");
FileInputStream fis = new FileInputStream(datafile);
byte[] dataBytes = new byte[1024];

int nread = 0; 

while ((nread = fis.read(dataBytes)) != -1) {
  md.update(dataBytes, 0, nread);
};

byte[] mdbytes = md.digest();

//convert the byte to hex format
StringBuffer sb = new StringBuffer("");
for (int i = 0; i < mdbytes.length; i++) {
    sb.append(Integer.toString((mdbytes[i] & 0xff) + 0x100, 16).substring(1));
}

System.out.println("Digest(in hex format):: " + sb.toString());

  }
  }

Jframe文件

import java.io.File;
  import java.io.IOException;
 import javax.swing.JFileChooser;


 public class FileExp extends javax.swing.JFrame {

/**
 * Creates new form FileExp
 */
public FileExp() {
    initComponents();
}

/**
 * This method is called from within the constructor to initialize the form.
 * WARNING: Do NOT modify this code. The content of this method is always
 * regenerated by the Form Editor.
 */
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">                          
private void initComponents() {

    filechoser = new javax.swing.JFileChooser();
    jScrollPane1 = new javax.swing.JScrollPane();
    jTextArea1 = new javax.swing.JTextArea();
    jMenuBar1 = new javax.swing.JMenuBar();
    jMenu1 = new javax.swing.JMenu();
    Open = new javax.swing.JMenuItem();
    Exit = new javax.swing.JMenuItem();

    setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

    jTextArea1.setColumns(20);
    jTextArea1.setRows(5);
    jScrollPane1.setViewportView(jTextArea1);

    jMenu1.setText("File");

            Open.setAccelerator(javax.swing.KeyStroke.getKeyStroke(java.awt.event.KeyEvent.VK_O, java.awt.event.InputEvent.META_MASK));
    Open.setText("Open");
    Open.addActionListener(new java.awt.event.ActionListener() {
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            OpenActionPerformed(evt);
        }
    });
    jMenu1.add(Open);

    Exit.setAccelerator(javax.swing.KeyStroke.getKeyStroke(java.awt.event.KeyEvent.VK_W, java.awt.event.InputEvent.META_MASK));
    Exit.setText("Exit");
    Exit.addActionListener(new java.awt.event.ActionListener() {
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            ExitActionPerformed(evt);
        }
    });
    jMenu1.add(Exit);

    jMenuBar1.add(jMenu1);

    setJMenuBar(jMenuBar1);

    javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
    getContentPane().setLayout(layout);
    layout.setHorizontalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(layout.createSequentialGroup()
            .addContainerGap()
            .addComponent(jScrollPane1, javax.swing.GroupLayout.DEFAULT_SIZE, 631, Short.MAX_VALUE)
            .addContainerGap())
    );
    layout.setVerticalGroup(
        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
            .addContainerGap(212, Short.MAX_VALUE)
            .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 136, javax.swing.GroupLayout.PREFERRED_SIZE)
            .addGap(42, 42, 42))
    );

    pack();
}// </editor-fold>                        

private void ExitActionPerformed(java.awt.event.ActionEvent evt) {                                     
  System.exit(0);

}                                    

private void OpenActionPerformed(java.awt.event.ActionEvent evt) {                                     
    int returnVal = filechoser.showOpenDialog(this);
    if (returnVal == JFileChooser.APPROVE_OPTION) {

        File file = filechoser.getSelectedFile();
        try {

        }
        catch (IOException ex){
            System.out.println("problem accessing file" + file.getAbsolutePath());

        }
    } else { System.out.println("File access cancelled by user.");

                }
    }
}                                    

/**
 * @param args the command line arguments
 */
public static void main(String args[]) {
    /* Set the Nimbus look and feel */
    //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
    /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
     * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
     */
    try {
        for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
            if ("Nimbus".equals(info.getName())) {
                javax.swing.UIManager.setLookAndFeel(info.getClassName());
                break;
            }
        }
    } catch (ClassNotFoundException ex) {
        java.util.logging.Logger.getLogger(FileExp.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (InstantiationException ex) {
        java.util.logging.Logger.getLogger(FileExp.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (IllegalAccessException ex) {
        java.util.logging.Logger.getLogger(FileExp.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (javax.swing.UnsupportedLookAndFeelException ex) {
        java.util.logging.Logger.getLogger(FileExp.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    }
    //</editor-fold>

    /* Create and display the form */
    java.awt.EventQueue.invokeLater(new Runnable() {
        public void run() {
            new FileExp().setVisible(true);
        }
    });
}

// Variables declaration - do not modify                     
private javax.swing.JMenuItem Exit;
private javax.swing.JMenuItem Open;
private javax.swing.JFileChooser filechoser;
private javax.swing.JMenu jMenu1;
private javax.swing.JMenuBar jMenuBar1;
private javax.swing.JScrollPane jScrollPane1;
private javax.swing.JTextArea jTextArea1;
// End of variables declaration                   
}

Answer 1

为什么不迭代File目录并对每个文件执行操作，如下所示：

File f = new File("directory");
for (File file : f.listFiles()) {
     generateSHA(file);
}

如果您使用JFileChooser选择文件而不是目录，只需使用for each循环遍历文件：

for (File file : fileList ) {
     generateSHA(file);
}

需要为JAVA中的一个文件夹生成多个文件的SHA-1值

1 个答案: