Java NIO: Getting file information with Files

Assuming your version of the Java SDK is 7+ you’ll be able to find an important class named Files in the java.nio.file package. This class consists of static methods for accessing information on different types of files, directories and the File System itself. It also enables programs to operate diversely on files and directories.

Let’s jump into a simple example to access a file and get in return information on it. We’ll start off by using our Paths utility method get to get the Path object off of a string path to the file. In this case, we’ll use the system arguments that we can easily pass into the program arguments when calling the java runtime environment (JRE). In this example, just as in many other you might find on the site I’m using the IntelliJ IDEA IDE you can find available here.

We’re working in a folder containing these files:

Here’s the code we’ll use for the demonstration:

import java.io.*;
import java.nio.file.*;

public class FileAttributes {

    public static void main(String[] args) throws IOException {
        try{
            Path imgPath = Paths.get("d:\\data", args[0]);
            if(imgPath != null){
                System.out.println("File name: " + imgPath.getName(1));
                System.out.println("Is hidden file:" + Files.isHidden(imgPath));
                System.out.println("Is readable file:" + Files.isReadable(imgPath));
                System.out.println("Is writable file:" + Files.isWritable(imgPath));
                System.out.println("Is directory file:" + Files.isDirectory(imgPath));
                System.out.println("Is hidden file:" + Files.isHidden(imgPath));
            }
        }catch (IOException ioe){
            System.err.println("IO Exception: " + ioe.getMessage());
        }
        catch (Exception ex){
            ex.printStackTrace();
        }
    }
}

The parameter we’re passing into the program is, in this case, a file name. Starting with the jpg image we have available (sample_image.jpg), we need to pass the name and extension as a parameter for the program. The way to do this will vary depending on the IDE you’re working with or whether your coding directly onto a notepad. If your case is the latter then you’ll simple compile & run the program as follows:

d:\java>javac FileAttributes.java

d:\java>java FileAttributes image_sample.jpg

However, if you’re using an IDE like Eclipse or IntelliJ, the procedure is a slightly different. Here’s how to do it in IntelliJ in two easy steps.