多线程自动监视并扫描指定文件夹中的文件变化

  采用多线程自动监视并扫描指定文件夹中的文件变化(文件数的变化和修改日期的变化),,实现其功能的代码由四个java文件组成 :FileListener.java,FileMonitor.java,FileTableModel.java,ParseUtility.java.其具体代码如下:



FileListener.java

package DirectoryScanner;

/**
 *
 * @author Hale Chou
 */
public interface FileListener {
    
    void dirChanged(FileMonitor monitor);
    
}

FileMonitor.java

package DirectoryScanner;

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

/**
 *
 * @author Hale Chou
 */
public class FileMonitor implements Runnable {
    List<FileListener> listenerList = new ArrayList<FileListener>();
    
    private File dir;
    private long interval;
    private long lastScanedTime;
    private int oldLength;
   
    public void addListener(FileListener listener) {
        listenerList.add(listener);
    }
   
    public void start(boolean isDamon) {
        Thread t = new Thread(this);
        t.setDaemon(isDamon);
        t.start();
    }

    public FileMonitor(String _dir, long intervalTime) {
        File f = new File(_dir);        
        if(!f.isDirectory())
            throw new RuntimeException();
        
        //筛选出不是标准文件的目录
        File[] fileList = f.listFiles();
        for( int i = 0; i < fileList.length; i++ ) {
            if(fileList[i].isDirectory()) {
                fileList[i].delete();
            }
        }
            
        this.dir = f;
        this.interval = intervalTime ;
        this.oldLength = dir.listFiles().length;
    }
   
    public File[] getMonitoredFile() {
        return this.dir.listFiles();
    }
   
    public void run() {
        while(true) {
            if(!dir.isDirectory())
                throw new RuntimeException();
            if(filesChanged()) {
                fireFilesChangedEvent(this);
            }
            try {
                Thread.sleep(interval);
            }catch(InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
   
    private void fireFilesChangedEvent(FileMonitor monitor) {
        for( int i = 0; i < listenerList.size(); i ++ ) {
            listenerList.get(i).dirChanged(monitor);
        }
    }
  
    protected boolean filesChanged() {
        File[] newFiles = dir.listFiles();
        if(newFiles.length != oldLength) {
            oldLength = newFiles.length;
            //System.out.println(newFiles.length);
            return true;
        }
        for( int i = 0; i < newFiles.length; i++ ) {
            if(newFiles[i].lastModified() >= lastScanedTime) {
                return true;
            }
        }
        return false ;
    }
}

FileTableModel.java

package DirectoryScanner;

import java.io.File;
import javax.swing.table.AbstractTableModel;

/**
 *
 * @author Hale Chou
 */
public class FileTableModel extends AbstractTableModel implements FileListener {
    private File[] files = null ;
    
    public FileTableModel(File dir) {
        files = dir.listFiles();        
    }

    public FileTableModel(File[] ff) {
        this.files = ff;            
    }
    
    public int getRowCount() {
        return  files.length;
    }
  
    //  Get a column's name.
    @Override
    public String getColumnName(int col) {
        String s = "文件名,路径,大小,修改时间";
        return s.split(",")[col];
    }
    
    public int getColumnCount() {
        return 4;
    }
  
    public Object getValueAt(int rowIndex, int columnIndex) {
        File f = files[rowIndex];
        
        if(f.isDirectory()){
            f.delete();
        }else{
            switch(columnIndex){
            case 0 :
                return f.getName();
            case 1 :
            return f.getPath();
            case 2 :
            return ParseUtility.bytes2kb(f.length());
            case 3 :
                return ParseUtility.toYYYYMMDDHHMMSS(f.lastModified());
            }
        }
        
        return "";
    }
  
    public void dirChanged(FileMonitor monitor) {
        this.files = monitor.getMonitoredFile();
        fireTableDataChanged();
    }
         
}

ParseUtility.java

package DirectoryScanner;

import java.math.BigDecimal;
import java.text.SimpleDateFormat;
import java.util.Date;

/**
 *
 * @author Administrator
 */
public class ParseUtility {
    
    public ParseUtility(){
    }
    
    public static String toYYYYMMDDHHMMSS(long time) {
        SimpleDateFormat format = new SimpleDateFormat("M月d日H时m分s秒");
        return format.format(new Date(time));
    }
    
    public static String bytes2kb(long bytes) {
        BigDecimal filesize = new BigDecimal(bytes);
        BigDecimal megabyte = new BigDecimal(1024 * 1024);
        float returnValue = filesize.divide(megabyte, 2 , BigDecimal.ROUND_UP).floatValue();
        if (returnValue > 1)
            return(returnValue + " MB");
        BigDecimal kilobyte = new BigDecimal(1024);
        returnValue = filesize.divide(kilobyte, 2 , BigDecimal.ROUND_UP).floatValue();
        return (returnValue + " KB");
    }
  
}

最后是调用程序

package file;

import java.io.File;
import javax.swing.table.TableModel;
import javax.swing.JFileChooser;
import javax.swing.event.*;

import DirectoryScanner.*;

/**
 *
 * @author  Hale Chou
 */
public class FileMonitorTest extends javax.swing.JFrame {
    
    public TableModel tableModel;
    
    /** Creates new form FileMonitorTest */
    public FileMonitorTest() {                      
        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.
     */
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {

        jScrollPane1 = new javax.swing.JScrollPane();
        jTable1 = new javax.swing.JTable();
        jLabel1 = new javax.swing.JLabel();
        txt_FilesCount = new javax.swing.JTextField();
        jLabel2 = new javax.swing.JLabel();
        txt_ScannedDirectory = new javax.swing.JTextField();
        btn_StartScan = new javax.swing.JButton();
        btn_SelectDirectory = new javax.swing.JButton();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        jTable1.setModel(new javax.swing.table.DefaultTableModel(
            new Object [][] {

            },
            new String [] {

            }
        ));
        jScrollPane1.setViewportView(jTable1);

        jLabel1.setText("当前文件数:");

        txt_FilesCount.setEditable(false);

        jLabel2.setText("选择文件夹:");

        btn_StartScan.setText("开始监视");
        btn_StartScan.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                btn_StartScanActionPerformed(evt);
            }
        });

        btn_SelectDirectory.setText("选择目录");
        btn_SelectDirectory.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                btn_SelectDirectoryActionPerformed(evt);
            }
        });

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addComponent(jScrollPane1, javax.swing.GroupLayout.DEFAULT_SIZE, 400, Short.MAX_VALUE)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(jLabel2)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addComponent(txt_ScannedDirectory, javax.swing.GroupLayout.PREFERRED_SIZE, 198, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                .addComponent(btn_SelectDirectory)
                .addContainerGap(31, Short.MAX_VALUE))
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(jLabel1)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addComponent(txt_FilesCount, javax.swing.GroupLayout.PREFERRED_SIZE, 198, 
                   javax.swing.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                .addComponent(btn_StartScan)
                .addContainerGap(31, Short.MAX_VALUE))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 170, 
                   javax.swing.GroupLayout.PREFERRED_SIZE)
                .addGap(18, 18, 18)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addComponent(jLabel2)
                    .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                        .addComponent(txt_ScannedDirectory, javax.swing.GroupLayout.PREFERRED_SIZE, 
                           javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addComponent(btn_SelectDirectory)))
                .addGap(18, 18, 18)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addComponent(jLabel1)
                    .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                        .addComponent(txt_FilesCount, javax.swing.GroupLayout.PREFERRED_SIZE, 
                           javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addComponent(btn_StartScan)))
                .addContainerGap(48, Short.MAX_VALUE))
        );

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

    private void btn_SelectDirectoryActionPerformed(java.awt.event.ActionEvent evt) {                                                    
        JFileChooser fc = new JFileChooser();
        
        fc.setDialogTitle("Select Directory");

        //fc.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
        fc.setFileSelectionMode(JFileChooser.FILES_AND_DIRECTORIES);
        
        int returnVal = fc.showOpenDialog(FileMonitorTest.this);
        
        if (returnVal == JFileChooser.APPROVE_OPTION) {
                File file = fc.getSelectedFile();              
                txt_ScannedDirectory.setText(file.getPath());
            }
        else {
            

            }
    }                                                   

    private void btn_StartScanActionPerformed(java.awt.event.ActionEvent evt) {                                              
        String directory = txt_ScannedDirectory.getText();        
        FileMonitor fileMonitor = new FileMonitor(directory, 100);
        tableModel = new FileTableModel(new File(directory));
        fileMonitor.addListener((FileListener)tableModel);
        fileMonitor.start(true);
        
        jTable1.setModel(tableModel);
        
        tableModel.addTableModelListener(new TableModelListener() {
                public void tableChanged(TableModelEvent e) {                    
                    if(tableModel.getRowCount()>0){
                        txt_FilesCount.setText(String.valueOf(tableModel.getRowCount()));
                    }
                    else{
                        txt_FilesCount.setText("shit,have nothing in it!");
                    }                    
                }
            });
    }                                             
    
    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new FileMonitorTest().setVisible(true);
            }
        });
    }
    
    // Variables declaration - do not modify                     
    private javax.swing.JButton btn_SelectDirectory;
    private javax.swing.JButton btn_StartScan;
    private javax.swing.JLabel jLabel1;
    private javax.swing.JLabel jLabel2;
    private javax.swing.JScrollPane jScrollPane1;
    private javax.swing.JTable jTable1;
    private javax.swing.JTextField txt_FilesCount;
    private javax.swing.JTextField txt_ScannedDirectory;
    // End of variables declaration                   
    
}