Question 1

When constructing a Scanner from a File object, the Scanner automatically constructs a ___________.

Accepted Answer

A)  InputStream 
B)  FileInputStream 
C)  FileReader 
D)  PrintWriter 
A)  InputStream 
B)  FileInputStream 
C)  FileReader 
D)  PrintWriter C

Question 2

The ____ class is used when writing text files.

Accepted Answer

A)  PrintWriter 
B)  InputStream 
C)  JFileChooser 
D)  Serializable 
A)  PrintWriter 
B)  InputStream 
C)  JFileChooser 
D)  Serializable A

Question 3

The two IO classes used for serialization are _______ and ________.

Accepted Answer

A)  Reader, Writer 
B)  ObjectInputStream, ObjectOutputStream 
C)  Scanner, PrintWriter 
D)  FileReader, FileWriter 
A)  Reader, Writer 
B)  ObjectInputStream, ObjectOutputStream 
C)  Scanner, PrintWriter 
D)  FileReader, FileWriter B

Question 4

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 5

Which of the following cannot be serialized?
I ArrayList<String>
II String
III Integer

Accepted Answer

A)  I 
B)  II and III 
C)  III 
D)  All can be serialized 
A)  I 
B)  II and III 
C)  III 
D)  All can be serialized

Question 6

__________ 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 7

Caesar cipher uses a shift of each character by a key with a value between 1 and 255. An a with a shift equal to 3 becomes a d. A z would become a c, wrapping around the alphabet. Which key should you use to encrypt picture into mfzqrob?

Accepted Answer

A)  3 
B)  19 
C)  -3 
D)  -19 
A)  3 
B)  19 
C)  -3 
D)  -19

Question 8

How many methods are required to implement the Serializable interface?

Accepted Answer

A)  3 
B)  2 
C)  1 
D)  0 
A)  3 
B)  2 
C)  1 
D)  0

Question 9

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 10

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 11

Which is an advantage of storing numbers in binary format?
I fast access
II less storage needed
III easy to read in a text editor

Accepted Answer

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

Question 12

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 13

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

Question 14

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 15

Assume we have a RandomAccessFile object, file, which stores a set of records of class MyData. The size of each record is MyData.RECORD_SIZE. Assume MyData has read and write methods, both of which take a RandomAccessFile as an argument. Method write writes the object at the current location. Method read reads the record from current location of the file into the object. If we are currently at the beginning of the 25th record, which code correctly modifies the 25th record by changing its color to Color.yellow through the setColor method?

Accepted Answer

A)  myData.read(file);
MyData.setColor(Color.yellow);
MyData.write(file); 
B)  myData.read(file);
MyData.setColor(Color.yellow);
File.seek(file.getFilePointer());
MyData.write(file); 
C)  myData.read(file);
MyData.setColor(Color.yellow);
File.seek(file.getFilePointer() + MyData.RECORD_SIZ
E) ;
MyData.write(file); 
D)  long loc = file.getFilePointer();
MyData.read(file);
MyData.setColor(Color.yellow);
File.seek(loc);
MyData.write(file); 
A)  myData.read(file);
MyData.setColor(Color.yellow);
MyData.write(file); 
B)  myData.read(file);
MyData.setColor(Color.yellow);
File.seek(file.getFilePointer());
MyData.write(file); 
C)  myData.read(file);
MyData.setColor(Color.yellow);
File.seek(file.getFilePointer() + MyData.RECORD_SIZ
E) ;
MyData.write(file); 
D)  long loc = file.getFilePointer();
MyData.read(file);
MyData.setColor(Color.yellow);
File.seek(loc);
MyData.write(file);

Question 16

Caesar cipher uses a shift of each character by a key with a value between 1 and 255. An a with a shift equal to 3 becomes a d. A z would become a c, wrapping around the alphabet. Which is the decryption of exmmv for a key = -3?

Accepted Answer

A)  cvkkt 
B)  atiir 
C)  bujjs 
D)  happy 
A)  cvkkt 
B)  atiir 
C)  bujjs 
D)  happy

Question 17

In Java, the byte type is a(n) ____ type.

Accepted Answer

A)  positive 
B)  signed 
C)  negative 
D)  unsigned 
A)  positive 
B)  signed 
C)  negative 
D)  unsigned

Question 18

Which statement is true regarding the following code, assuming reader is a FileInputStream object?
Char ch = (char) reader.read();
I you cannot determine if you have reached the end of input
II this code will throw an exception if we are at the end of input
III read returns an int, so the cast is illegal

Accepted Answer

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

Question 19

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 20

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

Exam 19: Streams and Binary Inputoutput

When constructing a Scanner from a File object, the Scanner automatically constructs a ___________.

The ____ class is used when writing text files.

The two IO classes used for serialization are _______ and ________.

Which interface allows classes to be written to an ObjectOutputStream?

Which of the following cannot be serialized? I ArrayList<String> II String III Integer

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

Caesar cipher uses a shift of each character by a key with a value between 1 and 255. An a with a shift equal to 3 becomes a d. A z would become a c, wrapping around the alphabet. Which key should you use to encrypt picture into mfzqrob?

How many methods are required to implement the Serializable interface?

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

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?

Which is an advantage of storing numbers in binary format? I fast access II less storage needed III easy to read in a text editor

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

Which method moves the file pointer in a RandomAccessFile?

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

Caesar cipher uses a shift of each character by a key with a value between 1 and 255. An a with a shift equal to 3 becomes a d. A z would become a c, wrapping around the alphabet. Which is the decryption of exmmv for a key = -3?

In Java, the byte type is a(n) ____ type.

Which class is used for input of text data?

Which file storage method stores data in bytes?

Introduction

Fundamental Data Types

Decisionseasy

Loops

Methods

Arrays and Arraylists

Inputoutput and Exception Handling

Objects and Classes

Inheritance and Interfaces

Graphical User Interfaces

Advanced User Interfaces

Object-Oriented Design

Recursion

Sorting and Searching

The Java Collections Framework

Basic Data Structures

Tree Structures

Generic Classes

Multithreading

Internet Networking

Relational Databases

XML

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Filters

The two IO classes used for serialization are _ and __.

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?