Question 1

In which of the following modes can a RandomAccessFiles be opened?
I "r"
II "rw"
III "w"

Accepted Answer

A)  I 
B)  II 
C)  I and II 
D)  I and III 
A)  I 
B)  II 
C)  I and II 
D)  I and III

Question 2

Which code stores an array buttonArray of JButton objects in a file named buttonFile? We ignore exceptions in this problem.

Accepted Answer

A)  ObjectStream os = new ObjectStream(new FileStream("buttonFile");
Os)writeObject(buttonArray); 
B)  ObjectOutputStream oos = new ObjectOutputStream(
New FileOutputStream("buttonFile");
Oos)writeObject(buttonArray); 
C)  ObjectOutputStream oos = new ObjectOutputStream(
New FileOutputStream("buttonFile");
Oos)writeObject(buttonArray[0]); 
D)  ObjectOutputStream oos = new ObjectOutputStream("buttonFile");
Oos)writeObject(buttonArray); 
A)  ObjectStream os = new ObjectStream(new FileStream("buttonFile");
Os)writeObject(buttonArray); 
B)  ObjectOutputStream oos = new ObjectOutputStream(
New FileOutputStream("buttonFile");
Oos)writeObject(buttonArray); 
C)  ObjectOutputStream oos = new ObjectOutputStream(
New FileOutputStream("buttonFile");
Oos)writeObject(buttonArray[0]); 
D)  ObjectOutputStream oos = new ObjectOutputStream("buttonFile");
Oos)writeObject(buttonArray);

Question 3

How many bytes does the read method in the InputStream class get from the file?

Accepted Answer

A)  1 
B)  2 
C)  4 
D)  8 
A)  1 
B)  2 
C)  4 
D)  8

Question 4

Which file storage method stores data in bytes?

Accepted Answer

A)  binary 
B)  object 
C)  text 
D)  byte 
A)  binary 
B)  object 
C)  text 
D)  byte

Question 5

Which interface allows classes to be written to an ObjectOutputStream?

Accepted Answer

A)  Objective 
B)  Streaming 
C)  Serializable 
D)  Objectifiable 
A)  Objective 
B)  Streaming 
C)  Serializable 
D)  Objectifiable

Question 6

Which class is used for input of text data?

Accepted Answer

A)  Reader 
B)  Writer 
C)  InputStream 
D)  OutputStream 
A)  Reader 
B)  Writer 
C)  InputStream 
D)  OutputStream

Question 7

Given a RandomAccessFile that stores a set of records of class MyData, each needing MyData.RECORD_SIZE bytes for storage, which expression gets the offset to the beginning of the 25th record?

Accepted Answer

A)  MyData.RECORD_SIZE * 25 
B)  MyData.RECORD_SIZE * 24 
C)  MyData.RECORD_SIZE++ 
D)  MyData.RECORD_SIZE + 25 
A)  MyData.RECORD_SIZE * 25 
B)  MyData.RECORD_SIZE * 24 
C)  MyData.RECORD_SIZE++ 
D)  MyData.RECORD_SIZE + 25

Question 8

If you want to process text data from a file, which keyword do you look for in classes that specialize in doing that?

Accepted Answer

A)  text 
B)  serializable 
C)  binary 
D)  reader 
A)  text 
B)  serializable 
C)  binary 
D)  reader

Question 9

Which of these classes access sequences of characters?
I readers
II writers
III streams

Accepted Answer

A)  I 
B)  II 
C)  I and II 
D)  II and III 
A)  I 
B)  II 
C)  I and II 
D)  II and III

Question 10

Assume we have a RandomAccessFile object, file, which stores a set of records of class MyData, each needing MyData.RECORD_SIZE bytes for storage. If the file pointer is currently on the 24th record, which expression gets to the offset of the beginning of the 25th record?

Accepted Answer

A)  MyData.RECORD_SIZE + 1 
B)  MyData.RECORD_SIZE + file.getFilePointer() 
C)  MyData.RECORD_SIZE * 2 
D)  file.getFilePointer() 
A)  MyData.RECORD_SIZE + 1 
B)  MyData.RECORD_SIZE + file.getFilePointer() 
C)  MyData.RECORD_SIZE * 2 
D)  file.getFilePointer()

Question 11

Which of the following statements enables you to write output to a text file?

Accepted Answer

A)  PrintWriter out = new PrintWriter(); 
B)  PrintWriter out = new PrintWriter("output.txt"); 
C)  FileReader reader = new FileReader("input.txt"); 
D)  Scanner in = new Scanner(reader); 
A)  PrintWriter out = new PrintWriter(); 
B)  PrintWriter out = new PrintWriter("output.txt"); 
C)  FileReader reader = new FileReader("input.txt"); 
D)  Scanner in = new Scanner(reader);

Question 12

__________ access allows file access at arbitrary locations, without first reading the bytes preceding the access location.

Accepted Answer

A)  Random 
B)  Serial 
C)  Sequential 
D)  Binary 
A)  Random 
B)  Serial 
C)  Sequential 
D)  Binary

Question 13

Which is not a method in the RandomAccessFile class?

Accepted Answer

A)  getFilePointer 
B)  seek 
C)  scan 
D)  length 
A)  getFilePointer 
B)  seek 
C)  scan 
D)  length

Question 14

The ______ method returns an integer, either -1 (at the end of the file) or a byte between 0 and 255.

Accepted Answer

A)  RandomAccessFile.seek 
B)  InputStream.read 
C)  Scanner.next 
D)  Reader.length 
A)  RandomAccessFile.seek 
B)  InputStream.read 
C)  Scanner.next 
D)  Reader.length

Question 15

Which line completes this code fragment so it creates a text file called "mychars.txt" and writes the characters 'A', 'B', and 'C' into the file? _____________________
Fw)write('A');
Fw)write('B');
Fw)write('C');

Accepted Answer

A)  PrintWriter fw = new PrintWriter("mychars.txt"); 
B)  FileOutputStream fw = new FileOutputStream("mychars.txt"); 
C)  File fw = new File("mychars.txt"); 
D)  PrintStream fw = new PrintStream("mychars.txt"); 
A)  PrintWriter fw = new PrintWriter("mychars.txt"); 
B)  FileOutputStream fw = new FileOutputStream("mychars.txt"); 
C)  File fw = new File("mychars.txt"); 
D)  PrintStream fw = new PrintStream("mychars.txt");

Question 16

The readInt and writeInt methods of the RandomAccessFile class read and write integers as ____ quantities.

Accepted Answer

A)  two-byte 
B)  four-byte 
C)  six-byte 
D)  eight-byte 
A)  two-byte 
B)  four-byte 
C)  six-byte 
D)  eight-byte

Question 17

Which method in the RandomAccessFile class provides for random access?

Accepted Answer

A)  move 
B)  seek 
C)  goto 
D)  offset 
A)  move 
B)  seek 
C)  goto 
D)  offset

Question 18

Which of the following classes are used with data in binary form?
I FileInputStream
II FileReader
III RandomAccessFile

Accepted Answer

A)  I 
B)  I and II 
C)  I and III 
D)  II and III 
A)  I 
B)  I and II 
C)  I and III 
D)  II and III

Question 19

In which package are most classes for file processing found?

Accepted Answer

A)  java.file 
B)  java.inputoutput 
C)  java.io 
D)  java.stream 
A)  java.file 
B)  java.inputoutput 
C)  java.io 
D)  java.stream

Question 20

Which method moves the file pointer in a RandomAccessFile?

Accepted Answer

A)  seek 
B)  length 
C)  getFilePointer 
D)  close 
A)  seek 
B)  length 
C)  getFilePointer 
D)  close

Exam 20: Streams and Binary Inputoutput

In which of the following modes can a RandomAccessFiles be opened? I "r" II "rw" III "w"

Which code stores an array buttonArray of JButton objects in a file named buttonFile? We ignore exceptions in this problem.

How many bytes does the read method in the InputStream class get from the file?

Which file storage method stores data in bytes?

Which interface allows classes to be written to an ObjectOutputStream?

Which class is used for input of text data?

Given a RandomAccessFile that stores a set of records of class MyData, each needing MyData.RECORD_SIZE bytes for storage, which expression gets the offset to the beginning of the 25th record?

If you want to process text data from a file, which keyword do you look for in classes that specialize in doing that?

Which of these classes access sequences of characters? I readers II writers III streams

Assume we have a RandomAccessFile object, file, which stores a set of records of class MyData, each needing MyData.RECORD_SIZE bytes for storage. If the file pointer is currently on the 24th record, which expression gets to the offset of the beginning of the 25th record?

Which of the following statements enables you to write output to a text file?

__________ access allows file access at arbitrary locations, without first reading the bytes preceding the access location.

Which is not a method in the RandomAccessFile class?

The ______ method returns an integer, either -1 (at the end of the file) or a byte between 0 and 255.

Which line completes this code fragment so it creates a text file called "mychars.txt" and writes the characters 'A', 'B', and 'C' into the file? _____________________ Fw)write('A'); Fw)write('B'); Fw)write('C');

The readInt and writeInt methods of the RandomAccessFile class read and write integers as ____ quantities.

Which method in the RandomAccessFile class provides for random access?

Which of the following classes are used with data in binary form? I FileInputStream II FileReader III RandomAccessFile

In which package are most classes for file processing found?

Which method moves the file pointer in a RandomAccessFile?

Introduction

Using Objects

Implementing Classes

Fundamental Data Types

Decisions

Loops

Arrays and Array Lists

Designing Classes

Inheritance

Interfaces

Inputoutput and Exception Handling

Object-Oriented Design

Recursion

Sorting and Searching

The Java Collections Framework

Basic Data Structures

Tree Structures

Generic Classes

Graphical User Interfaces

Multithreading

Internet Networking

Relational Databases

XML

Web Applications

Filters

Given a RandomAccessFile that stores a set of records of class MyData, each needing MyData.RECORD_SIZE bytes for storage, which expression gets the offset to the beginning of the 25^th record?

Assume we have a RandomAccessFile object, file, which stores a set of records of class MyData, each needing MyData.RECORD_SIZE bytes for storage. If the file pointer is currently on the 24^th record, which expression gets to the offset of the beginning of the 25^th record?