問題描述

URL url =  new URL("ftp://user:pass@ftp.example.com/thefolder/");
URLConnection connection = url.openConnection();
...
// List files in folder...

使用類似上面的方法，我想知道如何獲取文件夾thefolder"中的文件列表?

Using something like the above, I was wondering how I could grab a list of files within folder 'thefolder'?

從這個原始問題開始，我整理了這個簡單的 FTP 連接，它一切正常，看起來不錯.它可以看到/live/conf/位置的所有文件，并將它們全部復制到本地/conf/位置.

Following on from this original question, I have put together this simple FTP connection which is all working and looking good. It can see all files in the /live/conf/ location and copies them all to the local /conf/ location.

唯一的問題是，它正在復制文件但沒有內容.它們都是 0KB 并且是空的.

The only issue is, it is copying the files but there's no content.They are all 0KB and empty.

任何人都可以看到任何明顯的復制文件名而不是文件內容的內容嗎?

Can anyone see anything obvious that'd be copying the filename but not file content?

try {
    FTPClient ftp = new FTPClient();
    ftp.connect("000.000.000.000");
    ftp.login("USER", "PASSWORD");
    ftp.enterLocalPassiveMode();
    ftp.setFileType(FTP.BINARY_FILE_TYPE);

    FTPFile[] files = ftp.listFiles("/live/conf/");
    for (int i=0; i < files.length; i++) {
        if (files[i].getName().contains(".csv")) {

            String remoteFile1 = files[i].getName();
            File downloadFile1 = new File("/var/local/import/conf/"+files[i].getName());
            OutputStream outputStream1 = new BufferedOutputStream(new FileOutputStream(downloadFile1));
            ftp.retrieveFile(remoteFile1, outputStream1);
            outputStream1.close();                  

        }
    }
    ftp.disconnect();
} catch (SocketException ex) {
    ex.printStackTrace();
} catch (IOException ex) {
    ex.printStackTrace();
}   

推薦答案

Java SE URLConnection 不適合從 FTP 主機檢索文件列表的工作.至于 FTP，它基本上只支持 FTP 的 get 或 put 命令(檢索或上傳文件).它不支持您基本上正在尋找的 FTP ls 命令(列出文件)，更不用說其他許多命令了.

The Java SE URLConnection is insuitable for the job of retrieving a list of files from a FTP host. As to FTP, it basically only supports the FTP get or put commands (retrieve or upload file). It does not support the FTP ls command (list files) which you're basically looking for, let alone many others.

您需要尋找支持 FTP ls 命令(以及更多)的第 3 方庫.一個常用的是 Apache Commons Net FtpClient.在其 javadoc 是演示了如何發出 ls:

You need to look for 3rd party libraries supporting the FTP ls command (and many more). A commonly used one is the Apache Commons Net FtpClient. In its javadoc is demonstrated how to issue a ls:

FTPClient f = new FTPClient();
f.connect(server);
f.login(username, password);
FTPFile[] files = f.listFiles(directory);

這篇關于URLConnection FTP 列表文件的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！