1. Run ReadRandomLetters.java using Letters.dat

2. Move to character 100, and use EOFException to catch the error

3. Change the file to read and write using "rw

4. Printout the last char in the file (should be z)

5. Print out the middle characters in the file (should be m + n)

6. Write at the end of the file the characters A, B, Z (uppercase)

7. Put the string I am in the middle between the lowercase characters and the uppercase characters

8. Find the length of the file in bytes

9. Printout all the characters in file

ReadRandomLetters.java

import java.io.*;

/**

This program uses the RandomAccessFile class to open

the file Letters.dat and randomly read letters from

different locations.

*/

public class ReadRandomLetters

{

public static void main(String[] args) throws IOException

{

final int CHAR_SIZE = 2;// 2 byte characters

long byteNum; // The byte number

char ch; // A character from the file

// Open the file for reading.

RandomAccessFile randomFile =

new RandomAccessFile("Letters.dat", "r");

// Move to the character 5. This is the 6th

// character from the beginning of the file.

byteNum = CHAR_SIZE * 5;

randomFile.seek(byteNum);

// Read the character stored at this location

// and display it. Should be the letter f.

ch = randomFile.readChar();

System.out.println(ch);

// Move to character 10 (the 11th character),

// read the character, and display it.

// Should be the letter k.

byteNum = CHAR_SIZE * 10;

randomFile.seek(byteNum);

ch = randomFile.readChar();

System.out.println(ch);

// Move to character 3 (the 4th character),

// read the character, and display it.

// Should be the letter d.

byteNum = CHAR_SIZE * 3;

randomFile.seek(byteNum);

ch = randomFile.readChar();

System.out.println(ch);

// Close the file.

randomFile.close();

}

}

Letters.dat

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