How to make a file read only in Java

A Java program to demonstrate the use of java.io.File setReadOnly() method to make a file read only. Since JDK 1.6, a new setWritable() method is provided to make a file to be writable again.

Example

package com.mkyong;

import java.io.File;
import java.io.IOException;

public class FileReadAttribute
{
	
    public static void main(String[] args) throws IOException
    {	
    	File file = new File("c:/file.txt");
    	
    	//mark this file as read only, since jdk 1.2
    	file.setReadOnly();
    	
    	if(file.canWrite()){
    	     System.out.println("This file is writable");
    	}else{
    	     System.out.println("This file is read only");
    	}
    	
    	//revert the operation, mark this file as writable, since jdk 1.6
    	file.setWritable(true);
    	
    	if(file.canWrite()){
    	     System.out.println("This file is writable");
    	}else{
    	     System.out.println("This file is read only");
    	}   	
    }
}

Output

This file is read only
This file is writable