Question 1

You use _________ and FileOutputStream objects to write data to a disk file in text or binary form respectively.

Accepted Answer

A)  FileReader 
B)  PrintWriter 
C)  OutputStreamWriter 
D)  ObjectOutputStream 
A)  FileReader 
B)  PrintWriter 
C)  OutputStreamWriter 
D)  ObjectOutputStream B

Question 2

Which line completes this code fragment to define a text file named txtfile for reading? ____________________________________________________
String line = scan.nextLine();

Accepted Answer

A)  Reader scan = new Reader(new File("txtfile")); 
B)  FileReader scan = new File("txtfile"); 
C)  Scanner scan = new Scanner(System.in); 
D)  Scanner scan = new Scanner(new File("txtfile")); 
A)  Reader scan = new Reader(new File("txtfile")); 
B)  FileReader scan = new File("txtfile"); 
C)  Scanner scan = new Scanner(System.in); 
D)  Scanner scan = new Scanner(new File("txtfile")); D

Question 3

The FileInputStream read method reads binary data. What type is actually returned from a call to read?

Accepted Answer

A)  int 
B)  char 
C)  String 
D)  byte 
A)  int 
B)  char 
C)  String 
D)  byte A

Question 4

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 5

Which file storage method is in human-readable form?

Accepted Answer

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

Question 6

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 7

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

Question 8

What is the highest value for a signed (negative and positive) byte?

Accepted Answer

A)  127 
B)  128 
C)  255 
D)  256 
A)  127 
B)  128 
C)  255 
D)  256

Question 9

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

Accepted Answer

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

Question 10

Based on the code below, the statement that would move the file pointer to byte n counted from the beginning of the file is ___________________. RandomAccessFile test = new RandomAccessFile("record.bat", "r");

Accepted Answer

A)  test.getFilePointer(n); 
B)  test.getFilePointer(); 
C)  test.seek(n); 
D)  test.length() - n; 
A)  test.getFilePointer(n); 
B)  test.getFilePointer(); 
C)  test.seek(n); 
D)  test.length() - n;

Question 11

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. For the decrypt method below, select the correct body. Assume the key shift property is accessible to the method. public int decrypt(int B) { ________ }

Accepted Answer

A)  return (b + key); 
B)  return (b - key % 26); 
C)  return (b - key) % 256); 
D)  return (b - key); 
A)  return (b + key); 
B)  return (b - key % 26); 
C)  return (b - key) % 256); 
D)  return (b - key);

Question 12

Which of the following reads binary data from a disk file?

Accepted Answer

A)  PrintWriter text = new PrintWriter("input.bin"); 
B)  FileReader text = new FileReader("input.bin"); 
C)  FileInputStream inputStream = new FileInputStream("input.bin"); 
D)  FileWriter text = new FileWriter("input.bin"); 
A)  PrintWriter text = new PrintWriter("input.bin"); 
B)  FileReader text = new FileReader("input.bin"); 
C)  FileInputStream inputStream = new FileInputStream("input.bin"); 
D)  FileWriter text = new FileWriter("input.bin");

Question 13

If serializing object obj requires 12 bytes, how many bytes are required to serialize obj 3 times?

Accepted Answer

A)  12 bytes plus 3 serial numbers of obj 
B)  36 bytes 
C)  12 bytes 
D)  12 bytes plus 2 serial numbers of obj 
A)  12 bytes plus 3 serial numbers of obj 
B)  36 bytes 
C)  12 bytes 
D)  12 bytes plus 2 serial numbers of obj

Question 14

What is the result of the following code? Reader reader = … ; // connect to a file
Char ch = reader.read();

Accepted Answer

A)  compiler error 
B)  1 byte is read from the file 
C)  2 bytes are read from the file 
D)  4 bytes are read from the file 
A)  compiler error 
B)  1 byte is read from the file 
C)  2 bytes are read from the file 
D)  4 bytes are read from the file

Question 15

You cannot read a(n) ____________________ file with a text editor.

Accepted Answer

A)  random 
B)  serial 
C)  sequential 
D)  binary 
A)  random 
B)  serial 
C)  sequential 
D)  binary

Question 16

Which of the following classes are related through inheritance?
I InputStream
II InputStreamReader
III ObjectInputStream

Accepted Answer

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

Question 17

How many bytes does the read method in the FileInputStream class actually return to the program call?

Accepted Answer

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

Question 18

Objects are saved in ___________ format in object streams.

Accepted Answer

A)  binary 
B)  character 
C)  stream 
D)  integer 
A)  binary 
B)  character 
C)  stream 
D)  integer

Question 19

Why does FileInputStream override the read method from its superclass InputStream?

Accepted Answer

A)  In order to return a char. 
B)  In order to read binary data. 
C)  To read data from a file. 
D)  To check for end of file. 
A)  In order to return a char. 
B)  In order to read binary data. 
C)  To read data from a file. 
D)  To check for end of file.

Question 20

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

Exam 20: Streams and Binary Inputoutput

You use _________ and FileOutputStream objects to write data to a disk file in text or binary form respectively.

Which line completes this code fragment to define a text file named txtfile for reading? ____________________________________________________ String line = scan.nextLine();

The FileInputStream read method reads binary data. What type is actually returned from a call to read?

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

Which file storage method is in human-readable form?

The ____ class is used when writing text files.

What is the highest value for a signed (negative and positive) byte?

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

Based on the code below, the statement that would move the file pointer to byte n counted from the beginning of the file is ___________________. RandomAccessFile test = new RandomAccessFile("record.bat", "r");

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. For the decrypt method below, select the correct body. Assume the key shift property is accessible to the method. public int decrypt(int B) { ________ }

Which of the following reads binary data from a disk file?

If serializing object obj requires 12 bytes, how many bytes are required to serialize obj 3 times?

What is the result of the following code? Reader reader = … ; // connect to a file Char ch = reader.read();

You cannot read a(n) ____________________ file with a text editor.

Which of the following classes are related through inheritance? I InputStream II InputStreamReader III ObjectInputStream

How many bytes does the read method in the FileInputStream class actually return to the program call?

Objects are saved in ___________ format in object streams.

Why does FileInputStream override the read method from its superclass InputStream?

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

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

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