Get information from a file in Java

We show you the code to get information from a file in Java, with the help of the File class. The File class is in the java.io package that comes as part of the standard Java packages.

» See more examples

We show you the code:

package com.geekole; // Name of your java package

import java.io.File;

/**
 * @author geekole.com
 */

public class GetInformationFile {

    public static void main(String[] args) {
        File file = new File("/path/filename.txt");
        if (file.exists()) {
            System.out.println("Filename: " + file.getName());
            System.out.println("Absolute path: " + file.getAbsolutePath());
            System.out.println("Write permissions: " + file.canWrite());
            System.out.println("Read permissions: " + file.canRead());
            System.out.println("File size: " + file.length());
            System.out.println("Container folder: " + file.getParent());
            System.out.println("Is file: " + file.isFile());
            System.out.println("Is directory " + file.isDirectory());
            System.out.println("Is hidden: " + file.isHidden());
        } else {
            System.out.println("The file does not exists.");
        }
    }
}

In the first few lines after instantiating the File class with the file path, we first check that the file exists with the exist() method. This is a common practice that you should always consider when handling files.

        if (file.exists()) {
           .
        } else {
            System.out.println("The file does not exists.");
        }

We get the name and path of the file, in case we need to know it later:

            System.out.println("Filename: " + file.getName());
            System.out.println("Absolute path: " + file.getAbsolutePath());

We verify if the file has read or write permissions, this information is important because not having permissions is likely to generate an exception during file handling:

            System.out.println("Write permissions: " + file.canWrite());
            System.out.println("Read permissions: " + file.canRead());

And some other functions like knowing the name of the parent folder, if it is a file, if it is a directory or if it is a hidden file:

            System.out.println("Container folder: " + file.getParent());
            System.out.println("Is file: " + file.isFile());
            System.out.println("Is directory " + file.isDirectory());
            System.out.println("Is hidden: " + file.isHidden());

When compiling and executing the code we will obtain the information of the file, in our case we use Netbeans to test the example:

We hope that this example to obtain information from a file in Java will be useful to you, we also leave you the links to create or read text files:

• Create an XML file in Java
• Read a text file in Java

See more information: https://docs.oracle.com/javase/7/docs/api/java/io/File.html