Fill in the blanks in each of the following statements:

1. Ultimately, all data items processed by a computer are reduced to combinations of __________ and __________.

2. The smallest data item a computer can process is called a(n)__________.

3. A(n) __________ can sometimes be viewed as a group of related records.

4. Digits, letters and special symbols are referred to as __________.

5. A group of related files is called a __________.

6. Object __________ normally enables a program to output error messages to the screen.

7. RandomAccessFile method __________ reads an integer from the specified stream.

8. RandomAccessFile method __________ sets the file-position pointer to a specific location in a file for input or output.

Determine which of the following statements are true and which are false . If false , explain why.

1. The programmer must explicitly create the stream objects System.in , System.out and System.err .

2. When reading data from a file using class Scanner , if the programmer wishes to read data in the file multiple times, the file must be closed and reopened to read from the beginning of the file. This moves the file-position pointer back to the beginning of the file.

3. Method exists of class File returns TRue if the name specified as the argument to the File constructor is a file or directory in the specified path .

4. It is not necessary to search all the records in a random-access file to find a record.

5. Binary files are human readable.

6. An absolute path contains all the directories, starting with the root directory, that lead to a specific file or directory.

7. Class Formatter contains method printf , which enables formatted data to be output to the screen or to a file.

Complete the following tasks , assuming that each applies to the same program:

1. Write a statement that opens file "oldmast.txt" for inputuse Scanner variable inOldMaster .

2. Write a statement that opens file "trans.txt" for inputuse Scanner variable inTransaction .

3. Write a statement that opens file "newmast.txt" for output (and creation)use formatter variable outNewMaster .

4. Write the statements needed to read a record from the file "oldmast.txt" . The data read should be used to create an object of class AccountRecord use Scanner variable inOldMaster . Assume that class AccountRecord is the same as the AccountRecord class in Fig. 14.6.

5. Write the statements needed to read a record from the file "trans.txt" . The record is an object of class transactionRecord use Scanner variable inTransaction . Assume that class transactionRecord contains method setAccount (which takes an int ) to set the account number and method setAmount (which takes a double ) to set the amount of the transaction.

6. Write a statement that outputs a record to the file "newmast.txt" . The record is an object of type AccountRecord use Formatter variable outNewMaster .

Complete the following tasks, assuming that each applies to the same program:

1. Write a statement that opens file "oldmast.ser" for inputuse ObjectInputStream variable inOldMaster to wrap a FileInputStream object.

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2. Write a statement that opens file "trans.ser" for inputuse ObjectInputStream variable inTransaction to wrap a FileInputStream object.

3. Write a statement that opens file "newmast.ser" for output (and creation)use ObjectOutputStream variable outNewMaster to wrap a FileOutputStream .

4. Write a statement that reads a record from the file "oldmast.ser" . The record is an object of class AccountRecordSerializable use ObjectInputStream variable inOldMaster . Assume class AccountRecordSerializable is the same as the AccountRecordSerializable class in Fig. 14.17

5. Write a statement that reads a record from the file "trans.ser" . The record is an object of class transactionRecord use ObjectInputStream variable inTransaction .

6. Write a statement that outputs a record to the file "newmast.ser" . The record is an object of type AccountRecordSerializable use ObjectOutputStream variable outNewMaster .

Find the error in each block of code and show how to correct it.

1. Assume that account , company and amount are declared.

   ObjectOutputStream outputStream;
   
        outputStream.writeInt( account );
        outputStream.writeChars( company );
        outputStream.writeDouble( amount );
   

2. The following statements should read a record from the file "payables.txt" . The Scanner variable inPayable should be used to refer to this file.

   Scanner inPayable =
   
   new
   
   Scanner(
   
   new
   
   File(
   
   "payables.txt"
   
   ) );
        PayablesRecord record = ( PayablesRecord ) inPayable.readObject();