java.io.File canWrite()

Description

On this document we will be showing a java example on how to use the canWrite() method of File Class. This method is basically a check if the file can be written. On some platforms it may be possible to start the Java virtual machine with special privileges that allow it to modify files that are marked read-only. Consequently this method may return true even though the file is marked read-only.

This method returns SecurityException – If a security manager exists and its SecurityManager.checkWrite(java.lang.String) method denies write access to the file.

Method Syntax

public boolean canWrite()

Method Argument

Data Type Parameter Description
N/A N/A N/A

Method Returns

This method returns boolean, true if and only if the file system actually contains a file denoted by this abstract pathname and the application is allowed to write to the file; false otherwise.

Compatibility

Requires Java 1.0 and up

Java File canWrite() Example

Below is a java code demonstrates the use of canWrite() method of File class. The example presented might be simple however it shows the behaviour of the canWrite() method. Basically we initialize a new File object that corresponds to a physical file which is writable and then the canWrite() method is used to check if the input file is writeable.

package com.javatutorialhq.java.examples;

import java.io.File;

/*
 * This example source code demonstrates the use of  
 * canWrite() method of File class.
 * 
 */

public class FileCanWriteExample {

	public static void main(String[] args) {
		
		// initialize File object
		File file = new File("C:javatutorialhqtest.txt");
		// check first if file exists
		if(file.exists()){
			//check if file can be written
			if(file.canRead()){
				System.out.println("User have permission to write on the file");
			}
			else{
				System.out.println("File is read only");
			}
		}
		else{
			System.out.println("File does not exists");
		}	
		
		
	}

}

Sample Output

Below is the sample output when you run the above example.

java lang File canWrite() example output