How can I change a file attribute to read only in Java?

This code demonstrate how we can modify file attribute to be read only. File class has a setReadOnly() method to make file read only and a canWrite() method to know whether it is writable or not.

import java.io.File;

public class FileReadOnlyExample
{
    public static void main(String[] args) throws Exception
    {
        File file = new File("ReadOnly.txt");

        // Create a file only if it doesn't exist.
        file.createNewFile();

        // Set file attribute to read only so that it cannot be written
        file.setReadOnly();

        // We are using the canWrite() method to check whether we can
        // modified file content.
        if (file.canWrite())
        {
            System.out.println("File is writable!");
        } else
        {
            System.out.println("File is in read only mode!");
        }
    }
}