FSformat.java

package external_tools;

import java.io.*;

public class FSformat {

 private RandomAccessFile file;
 private int magic = 0x1234ABCD;
 private long magicPosition = 0;
 private long currPositon = 0;
 private int directoryBlock = 1;
 private long directoryPosition = 8;
 private int firstFreeBlock = 2;
 private long freePosition = 12;
 
 public void start(String filename) {
	try {
	 file = new RandomAccessFile(filename,"rw");
	 if ( testFormated() ) {
		System.out.println("Already formated.");
	 }
	 else {
		format();
	 }
	}
	catch ( IOException e ) {
	 System.out.print("IO Exception - BlockDevice file not found.");
	}
 }

 private boolean testFormated() throws IOException {
 file.seek(magicPosition);
	int key = file.readInt(); //read and writes advances file pos pointer

	if ( key == magic ) {
	 return true;
	}
	else {
	 return false;
	}
 }

 private void format() throws IOException {
	//Write magic number as the first 32bit word on the super block
	file.seek(magicPosition);
	file.writeInt(magic);

	//Set directory block number as third 32bit word
	file.seek(directoryPosition);
	file.writeInt(directoryBlock);

	//Set block number of start of free block chain as fourth 32bit word, which is after the directory block number in the super block
	file.writeInt(firstFreeBlock);

	
 }
 
}