我有这个类，并且发现我试图编辑文本以反映下载文件的当前状态的JButton在FTPclient断开之前不会更新。 由于我不确定导致问题的原因，我将添加围绕需要发生的整个主类，我还使用播放声音的方法对其进行调试，每当我尝试更新JButton的文本时都会触发。测试时似乎工作正常。
public class Main {
public static JButton btnNewButton = null;
private JFrame frame;
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
Main window = new Main();
window.frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the application.
*/
public Main() {
initialize();
}
/**
* Initialize the contents of the frame.
*/
private void initialize() {
frame = new JFrame();
frame.setTitle("FTP Request");
BorderLayout borderLayout = (BorderLayout) frame.getContentPane()
.getLayout();
borderLayout.setVgap(19);
frame.getContentPane().setBackground(new Color(51, 51, 102));
frame.setBounds(500, 500, 616, 413);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setExtendedState(Frame.MAXIMIZED_BOTH);
// frame.setUndecorated(true);
// frame.setAlwaysOnTop(true);
btnNewButton = new JButton("EXIT");
btnNewButton.setFont(new Font("Impact", Font.BOLD, 40));
btnNewButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
btnNewButton.setText("Exitng...");
System.exit(0);
}
});
frame.getContentPane().add(btnNewButton, BorderLayout.SOUTH);
final JLabel lblStatus = new JLabel(new ImageIcon(
Main.class.getResource("/com/daniel/status1.png")));
frame.getContentPane().add(lblStatus, BorderLayout.EAST);
lblStatus.addMouseListener(new MouseAdapter() {
@Override
public void mouseClicked(MouseEvent arg0) {
System.out.println("CLICKED");
btnNewButton.setText("CLIEKCED");
playSound("1");
String server = "f12-preview.royalwebhosting.net";
int port = 21;
String user = "1951435";
String pass = "bgscoffee1";
FTPClient ftpClient = new FTPClient();
try {
// connect and login to the server
ftpClient.connect(server, port);
ftpClient.login(user, pass);
// use local passive mode to pass firewall
ftpClient.enterLocalPassiveMode();
playSound("2");
System.out.println("Connected");
btnNewButton.setText("Connected");
String remoteDirPath = "";
String saveDirPath = new File(path).getParent().toString()
+ "/Download";
FTPUtil.downloadDirectory(ftpClient, remoteDirPath, "",
saveDirPath);
// log out and disconnect from the server
ftpClient.logout();
ftpClient.disconnect();
playSound("3");
System.out.println("Disconnected");
btnNewButton.setText("Disconnected");
} catch (IOException ex) {
System.out.println("Error: " + ex.getMessage());
btnNewButton.setText("Error: " + ex.getMessage());
playSound("error");
ex.printStackTrace();
}
}
});
}
public static synchronized void playSound(final String url) {
new Thread(new Runnable() {
// The wrapper thread is unnecessary, unless it blocks on the
// Clip finishing; see comments.
public void run() {
try {
Clip clip = AudioSystem.getClip();
AudioInputStream inputStream = AudioSystem.getAudioInputStream(Main.class
.getResource("/com/daniel/" + url + ".wav"));
clip.open(inputStream);
clip.start();
} catch (Exception e) {
System.err.println(e.getMessage());
}
}
}).start();
}
}
仅供参考，我的FTPUtils课就在这里。
public class FTPUtil {
/**
* Download a whole directory from a FTP server.
* @param ftpClient an instance of org.apache.commons.net.ftp.FTPClient class.
* @param parentDir Path of the parent directory of the current directory being
* downloaded.
* @param currentDir Path of the current directory being downloaded.
* @param saveDir path of directory where the whole remote directory will be
* downloaded and saved.
* @throws IOException if any network or IO error occurred.
*/
public static void downloadDirectory(FTPClient ftpClient, String parentDir,
String currentDir, String saveDir) throws IOException {
String dirToList = parentDir;
if (!currentDir.equals("")) {
dirToList += "/" + currentDir;
}
FTPFile[] subFiles = ftpClient.listFiles(dirToList);
if (subFiles != null && subFiles.length > 0) {
for (FTPFile aFile : subFiles) {
String currentFileName = aFile.getName();
if (currentFileName.equals(".") || currentFileName.equals("..")) {
// skip parent directory and the directory itself
continue;
}
String filePath = parentDir + "/" + currentDir + "/"
+ currentFileName;
if (currentDir.equals("")) {
filePath = parentDir + "/" + currentFileName;
}
String newDirPath = saveDir + parentDir + File.separator
+ currentDir + File.separator + currentFileName;
if (currentDir.equals("")) {
newDirPath = saveDir + parentDir + File.separator
+ currentFileName;
}
if (aFile.isDirectory()) {
// create the directory in saveDir
File newDir = new File(newDirPath);
boolean created = newDir.mkdirs();
if (created) {
System.out.println("CREATED the directory" + newDirPath);
Main.btnNewButton.setText("CREATED the directory: " + newDirPath);
} else {
Main.btnNewButton.setText("COULD NOT create the directory: " + newDirPath);
}
// download the sub directory
downloadDirectory(ftpClient, dirToList, currentFileName,
saveDir);
} else {
// download the file
boolean success = downloadSingleFile(ftpClient, filePath,
newDirPath);
if (success) {
System.out.println("Downloaded: " + filePath);
Main.btnNewButton.setText("DOWNLOADED the file: " + filePath);
} else {
System.out.println("FAIL DOWNLOAD: " + filePath);
Main.btnNewButton.setText("COULD NOT download the file: "
+ filePath);
}
}
}
}
}
/**t
* Download a single file from the FTP server
* @param ftpClient an instance of org.apache.commons.net.ftp.FTPClient class.
* @param remoteFilePath path of the file on the server
* @param savePath path of directory where the file will be stored
* @return true if the file was downloaded successfully, false otherwise
* @throws IOException if any network or IO error occurred.
*/
public static boolean downloadSingleFile(FTPClient ftpClient,
String remoteFilePath, String savePath) throws IOException {
File downloadFile = new File(savePath);
File parentDir = downloadFile.getParentFile();
if (!parentDir.exists()) {
parentDir.mkdir();
}
OutputStream outputStream = new BufferedOutputStream(
new FileOutputStream(downloadFile));
try {
ftpClient.setFileType(FTP.BINARY_FILE_TYPE);
return ftpClient.retrieveFile(remoteFilePath, outputStream);
} catch (IOException ex) {
Main.btnNewButton.setText("ERROR " + ex.toString());
throw ex;
} finally {
if (outputStream != null) {
outputStream.close();
}
}
}
}