How can I change file attribute to writable?

By Wayan in Core API, IO 0 Comment

Prior to Java 1.6 the java.io.File class doesn’t include a method to change a read only file attribute and make it writable. To do this on the old days we have to utilize or called operating system specific command. In Java 1.6 a new method named setWritable() was introduced to do exactly what the method name says.

package org.kodejava.io;

import java.io.File;

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

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

        // Set file attribute to read only so that it cannot be written
        boolean succeeded = 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!");
        }

        // Now make our file writable
        succeeded = file.setWritable(true);

        // re-check the read-write status of file
        if (file.canWrite()) {
            System.out.println("File is writable!");
        } else {
            System.out.println("File is in read only mode!");
        }
    }
}

And here are the result of the code snippet above:

File is in read only mode!
File is writable!

How can I change file attribute to read only?

By Wayan in Core API, IO 0 Comment

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.

package org.kodejava.io;

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.
        boolean created = file.createNewFile();

        // Set file attribute to read only so that it cannot be written
        boolean succeeded = 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!");
        }
    }
}

This code snippet print the following output:

File is in read only mode!

How do I determine if a pathname is a directory?

By Wayan in Core API, IO 0 Comment

To determine if an abstract pathname is a directory we can use the File.isDirectory() method. Here is an example code.

package org.kodejava.io;

import java.io.File;

public class IsDirectoryExample {
    public static void main(String[] args) {
        // Creates a instance of File.
        File file = new File("C:/Users/wsaryada");

        // Check if the abstract pathname is a directory by calling
        // isDirectory() method of the File class.
        if (file.isDirectory()) {
            System.out.println("This file is a directory.");
        } else {
            System.out.println("This is just an ordinary file.");
        }
    }
}

How do I rename a file or directory?

By Wayan in Core API, IO 0 Comment 
package org.kodejava.io;

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

public class FileRenameExample {
    public static void main(String[] args) throws IOException {
        // Creates a new file called OldHouses.csv
        File oldFile = new File("OldHouses.csv");
        boolean created = oldFile.createNewFile();
        System.out.println("File created? " + created);

        // Creates the target file.
        File newFile = new File("NewHouses.csv");

        // The renameTo() method renames file or directory to a
        // new name by passing the new destination file.
        boolean renamed = oldFile.renameTo(newFile);
        System.out.println("File renamed? " + renamed);
    }
}

How do I check if a file is hidden?

By Wayan in Core API, IO 0 Comment

The File.isHidded() method checks to see if the file represented by aFile object is a hidden file. The definition of hidden is varied between operating systems. On UNIX based systems, a file is considered to be hidden when their name begins with a period character ('.'). On Windows operating system, a file is considered to be hidden if it has been marked hidden in the filesystem.

This File.isHidden() method returns true if and only if the file denoted by this File object is hidden according to the conventions of the underlying platform.

package org.kodejava.io;

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

public class FileHiddenExample {
    public static void main(String[] args) throws IOException {
        File file = new File("Hidden.txt");
        file.createNewFile();

        // We are using the isHidden() method to check whether a file
        // is hidden.
        if (file.isHidden()) {
            System.out.println("File is hidden!");
        } else {
            System.out.println("File is not hidden!");
        }
    }
}

If you want to set the file attribute to hidden in Windows operating system you can see it in the following example: How do I set the value of file attributes?