Java FTP example - Get details of a file or directory on server

In Java FTP programming with Apache Commons Net API, to know details of a file or directory such as size and last modified date (timestamp) from a FTP server, we can use the mlistFile() method of the FTPClient class as follows:

FTPFile ftpFile = ftpClient.mlistFile(remoteFilePath);

Where remoteFilePath is a String represents path of the file or directory (can be relative or absolute to the user’s home directory on the server). If the specified file/directory exists, the method returns a FTPFile object, otherwise it returns null. Then we can use some getter methods of the FTPFile class to get desired information as follows:

• • String getGroup(): gets name of the group owning the file.
  • String getName(): gets name of the file.
  • String getRawListing(): gets server raw listing of the file.
  • long getSize(): gets file size in bytes.
  • Calendar getTimestamp(): gets timestamp.
  • int getType(): gets type of the file.
  • String getUser(): gets name of the user owning the file.

The following is code of an example program that logins to a FTP server then gets details of a file using the mlistFile() method:

package net.codejava.ftp;

import java.io.IOException;

import org.apache.commons.net.ftp.FTPClient;
import org.apache.commons.net.ftp.FTPFile;

/**
 * An example program that demonstrates how to get details of a file and
 * directory from a FTP server using Apache Commnons Net API.
 * @author www.codejava.net
 *
 */
public class FTPGetFileDetails {

	public static void main(String[] args) {
		String server = "www.myserver.com";
		int port = 21;
		String user = "username";
		String pass = "password";

		FTPClient ftpClient = new FTPClient();

		try {
			ftpClient.connect(server, port);
			ftpClient.login(user, pass);

			// use local passive mode to pass firewall
			ftpClient.enterLocalPassiveMode();

			// get details of a file or directory
			String remoteFilePath = "Java/CodeLib/FTP.rar";

			FTPFile ftpFile = ftpClient.mlistFile(remoteFilePath);
			if (ftpFile != null) {
				String name = ftpFile.getName();
				long size = ftpFile.getSize();
				String timestamp = ftpFile.getTimestamp().getTime().toString();
				String type = ftpFile.isDirectory() ? "Directory" : "File";

				System.out.println("Name: " + name);
				System.out.println("Size: " + size);
				System.out.println("Type: " + type);
				System.out.println("Timestamp: " + timestamp);
			} else {
				System.out.println("The specified file/directory may not exist!");
			}

			ftpClient.logout();
			ftpClient.disconnect();

		} catch (IOException ex) {
			ex.printStackTrace();
		} finally {
			if (ftpClient.isConnected()) {
				try {
					ftpClient.disconnect();
				} catch (IOException ex) {
					ex.printStackTrace();
				}
			}
		}
	}
} 

Here’s the output when running the above program:

Name: Java/CodeLib/FTP.rar
Size: 13021440
Type: File
Timestamp: Sat Jul 13 13:11:04 ICT 2013 

API References:

• • Apache Commons Net API
  • FTPClient class Javadoc
  • mlistFile() method Javadoc
  • FTPFile class Javadoc

Related Java FTP Tutorials:

• Determine if a directory or file exists on FTP server
• Java FTP example - Get and set file modification time
• Get size of a file on FTP server
• Rename file or directory on FTP server
• Delete a file on a FTP server

Other Java FTP Tutorials:

• Connect and login to a FTP server
• Java FTP example - Change working directory
• Java FTP create directory example
• Java FTP list files and directories example
• Java FTP file download tutorial and example
• Java FTP file upload tutorial and example
• Java FTP example - Search for files and directories
• How to upload a directory to a FTP server
• How to download a complete folder from a FTP server

About the Author:

Nam Ha Minh is certified Java programmer (SCJP and SCWCD). He began programming with Java back in the days of Java 1.4 and has been passionate about it ever since. You can connect with him on Facebook and watch his Java videos on YouTube.

Attachments:

FTPGetFileDetails.java

[Java FTP get file details example program]

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