Deck 11: Exceptions and Advanced File Io

Question 1

When you deserialize an object using the readObject method, you must cast the return value to the desired class type.

Answer 1

True

Question 2

Beginning with Java7, to catch multiple exceptions with a single catch, you can use __________.

A) multi-catch
B) catch templates
C) multi-try
D) catchAll

Answer 2

A

Question 3

A class must implement the Serializable interface in order for the objects of the class to be serialized.

Answer 3

True

Question 4

All of the exceptions you will handle are instances of classes that extend the __________ class.

A) RunTimeException
B) IOException
C) Error
D) Exception

Question 5

The throw statement informs the compiler that a method throws one or more exceptions.

Question 6

The ability to catch multiple types of exceptions with a single catch clause is known as multi-catch and was introduced in Java 7.

Question 7

The call stack is an internal list of all the methods that are currently executing.

Question 8

If the class SerializedClass contains references to objects of other classes as fields, those classes must also implement the Serializable interface in order to be serialized.

Question 9

When catching multiple exceptions that are related to one another through inheritance you should handle the more general exception classes before the more specialized exception classes.

Question 10

The throws clause causes an exception to be thrown.

Question 11

In a try statement, the try clause must appear first, followed by all of the catch clauses, followed by the optional finally clause.

Question 12

When you write a method that throws a checked exception, you must __________.

A) override the default error method
B) ensure that the error will occur at least once each time the program is executed
C) have a throws clause in the method header
D) use each class only once in a method

Question 13

The catch clause __________.

A) starts with the word catch followed by a parameter list in parentheses containing an ExceptionType parameter variable
B) follows the try clause
C) contains code to gracefully handle the exception type listed in the parameter list
D) The catch clause does all of these

Question 14

When an exception is thrown by a method that is executing under several layers of method calls, a stack trace indicates the method executing when an exception occurred and all of the methods that were called in order to execute that method.

Question 15

When the code in a try block may throw more than one type of exception, you need to write a catch clause for each type of exception that could potentially be thrown.

Question 16

When an object is serialized, it is converted into a series of bytes that contain the object's data.

Question 17

In versions of Java prior to Java 7 each catch clause could handle only one type of exception.

Question 18

When writing a string to a binary file or reading a string from a binary file, it is recommended that you use __________.

A) methods that use UTF-8 encoding
B) the FileReader and Writer class methods
C) the Scanner class methods
D) the System.In and System.out methods

Question 19

All exceptions are instances of classes that extend the __________ class.

A) RunTimeException
B) Throwable
C) Error
D) Exception

Question 20

A catch clause that uses a parameter variable of the Exception type is capable of catching any exception that extends the Error class.

Question 21

When an exception is thrown __________.

A) it must always be handled by the method that throws it
B) it must be handled by the program or by the default exception handler
C) it may be ignored
D) the program terminates even if the exception is handled

Question 22

To read data from a binary file, you create objects from which of the following classes?

A) File and Scanner
B) File and PrintWriter
C) BinaryFileReader and BinaryDataReader
D) FileInputStream and DataInputStream

Question 23

To write data to a binary file, you create objects from which of the following classes?

A) File and Scanner
B) BinaryFileWriter and BinaryDataWriter
C) FileOutputStream and DataOutputStream
D) File and PrintWriter

Question 24

A(n) __________ contains one or more statements that are executed and can potentially throw an exception.

A) exception block
B) catch block
C) try block
D) error block

Question 25

The try statement may have an optional __________ clause which must appear after all of the catch clauses.

A) try-again
B) finally
C) default
D) abort

Question 26

All of the exceptions that you will handle are instances of classes that extend the __________ class.

A) IOException
B) Exception
C) Error
D) RunTimeException

Question 27

If a random access file contains a stream of characters, which of the following statements would move the file pointer to the starting byte of the fifth character in the file?

A) file.seek(4);
B) file.seek(8);
C) file.seek(10);
D) file.seek(5);

Question 28

In a try/catch construct, after the catch statement is executed __________.

A) the program returns to the statement following the statement in which the exception occurred
B) the program terminates
C) the program resumes at the statement that immediately follows the try/catch construct
D) the program resumes at the first statement of the try statement

Question 29

In Java there are two categories of exceptions which are __________.

A) unchecked and checked
B) runtime and compile-time
C) critical and nominal
D) static and dynamic

Question 30

An exception object's default error message can be retrieved using the __________ method.

A) getMessage
B) getDefaultMessage
C) getDefaultErrorMessage
D) getErrorMessage

Question 31

The numeric classes' parse methods all throw an exception of __________ type if the string being converted does not contain a convertible numeric value.

A) NumberFormatException
B) ParseIntException
C) ExceptionMessage
D) FileNotFoundException

Question 32

In order for an object to be serialized, its class must implement the __________ interface.

A) Serial
B) Serializable
C) ObjectOutputStream
D) Writeable

Question 33

A(n) __________ is a section of code that gracefully responds to exceptions when they are thrown.

A) exception
B) default exception handler
C) exception handler
D) thrown class

Question 34

A file that contains raw binary data is known as a __________.

A) binary file
B) machine file
C) serial file
D) raw data file

Question 35

In a multi-catch (introduced in Java 7) the exception types are separated in the catch clause by the __________ symbol.

A) *
B) ?
C) |
D) &

Question 36

If your code does not handle an exception when it is thrown, __________ prints an error message and crashes the program.

A) the Java error handler.
B) multi-catch
C) default exception handler
D) try statement

Question 37

An exception's default error message can be retrieved by using the __________ method.

A) getMessage()
B) getErrorMessage()
C) getDefaultMessage()
D) getDefaultErrorMessage()

Question 38

To serialize an object and write it to the file, use the __________ method of the ObjectOutputStream class.

A) WriteObject
B) SerializeObject
C) Serialize
D) SerializeAndWrite

Question 39

What happens if a program does not handle an unchecked exception?

A) This isn't possible; the program must handle the exception.
B) The program is halted and the default exception handler handles the exception.
C) The exception is ignored.
D) A compiler error will occur.

Question 40

A(n) __________ is an object that is generated in memory as the result of an error or an unexpected event.

A) exception
B) exception handler
C) default exception handler
D) error message

Question 41

Unchecked exceptions are those that inherit from the __________.

A) Error class or the RuntimeException class
B) Error class or the Exception class
C) Error class
D) ExceptionClass class or the RuntimeException class

Question 42

The IllegalArgumentException class extends the RuntimeException class and is, therefore, __________.

A) a checked exception class
B) an unchecked exception class
C) never used directly
D) None of these

Question 43

When using the throw statement, if you don't pass a message to the exception object's constructor, then __________.

A) the exception will have a null message
B) the exception will have a message containing the address of the exception
C) the exception will have a default message describing the exception
D) a compiler error will occur

Question 44

Classes that inherit from the Error class are for exceptions that are thrown when __________.

A) an IOException occurs, and the application program should not try to handle them
B) a critical error occurs, and the application program should not try to handle them
C) an IOException occurs, and the application program should try to handle them
D) a critical error occurs, and the application program should try to handle them

Question 45

The following catch statement can __________. catch (Exception e) {...}

A) handle all throwable objects by using a polymorphic reference for the parameter
B) handle all exceptions that are instances of the Exception class or one of its subclasses
C) handle all exceptions that are instances of the Exception class but not its subclasses
D) cause a compiler error

Question 46

If a method does not handle a possible checked exception, what must the method have?

A) a try clause in its header
B) a catch clause in its header
C) a finally clause in its header
D) a throws clause in its header

Question 47

When an exception is thrown by code in its try block, the JVM begins searching the try statement for a catch clause that can handle it and passes control of the program to __________.

A) the last catch clause that can handle the exception
B) each catch clause that can handle the exception
C) the first catch clause that can handle the exception
D) the statement that appears immediately after the catch block

Question 48

What will be the result of the following statements? FileOutputStream fstream = new FileOutputStream("Output.dat");
DataOutputStream outputFile = new DataOutputStream(fstream);

A) The outputFile variable will reference an object that is able to write text data only to the Output.dat file.
B) The outputFile variable will reference an object that is able to write binary data to the Output.dat file.
C) The outputFile variable will reference an object that is able to read binary data from the Output.dat file.
D) The outputFile variable will reference an object that is able to write binary data to the Output.dat as a random access file.

Question 49

In a catch statement, what does the following code do? System.out.println(e.getMessage());

A) It prints the code that caused the exception.
B) It prints the stack trace.
C) It prints the error message for an exception.
D) It overrides the toString method.

Question 50

Assume that the classes BlankISBN, NegativePrice, and NegativeNumberOrdered are exception classes that inherit from Exception. The following code is a constructor for the Book class. What must be true about any method that instantiates the Book class with this constructor? public Book(String ISBNOfBook, double priceOfBook,
Int numberOrderedOfBook)
{
If (ISBNOfBook == "")
Throw new BlankISBN();
If (priceOfBook < 0)
Throw new NegativePrice(priceOfBook);
If (numberedOrderedOfBook < 0)
Throw new NegativeNumberOrdered(numberOrderedv);
ISBN = ISBNOfBook;
Price = priceOfBook;
NumberedOrdered = numberOrderedOfBook;
}

A) It must call the constructor with valid data or a compiler error will occur.
B) It must contain an inner class that extends the IOException class.
C) It must handle all of the possible exceptions thrown by the constructor or have its own throws clause specifying them.
D) All of these are true.

Question 51

What will be the result of the following statements? FileInputStream fstream = new FileInputStream("Input.dat");
DataInputStream inFile = new DataInputStream(fstream);

A) The inFile variable will reference an object that is able to read random access data from the Input.dat file.
B) The inFile variable will reference an object that is able to read text data from the Input.dat file.
C) The inFile variable will reference an object that is able to read binary data from the Input.dat file.
D) The inFile variable will reference an object that is able to write binary data to the Input.dat file.

Question 52

Given the following constructor code, which of the statements are true? public Book(String ISBNOfBook, double priceOfBook,
Int numberOrderedOfBook)
{
If (ISBNOfBook == "")
Throw new BlankISBN();
If (priceOfBook < 0)
Throw new NegativePrice(priceOfBook);
If (numberedOrderedOfBook < 0)
Throw new NegativeNumberOrdered(numberOrderedv);
ISBN = ISBNOfBook;
Price = priceOfBook;
NumberedOrdered = numberOrderedOfBook;
}

A) There is an error: a throws clause should be added to the constructor header.
B) Classes extending the Exception class should be created for each of the custom exceptions that are thrown in the constructor.
C) A FileNotFoundException will be thrThe calling method must handle the exceptions thrown in the constructor, or have its own throws clause specifying them.
D) All of these are true.

Question 53

If you want to append data to an existing binary file, BinaryFile.dat, which of the following statements would you use to open the file?

A) FileOutputStream fstream =
New FileOutputStream("BinaryFile.dat");
DataOutputStream binaryOutputFile =
New DataOutputStream(fstream);
B) FileOutputStream fstream =
New FileOutputStream("BinaryFile.dat", false);
DataOutputStream binaryOutputFile =
New DataOutputStream(fstream);
C) FileOutputStream fstream =
New FileOutputStream("BinaryFile.dat", true);
DataOutputStream binaryOutputFile =
New DataOutputStream(fstream);
D) IFileOutputStream fstream =
New FileOutputStream("BinaryFile.dat");
DataOutputStream binaryOutputFile =
New DataOutputStream(fstream, true);

Question 54

If the data.dat file does not exist, what will happen when the following statement is executed? RandomAccessFile randomFile = new RandomAccessFile("data.dat", "rw");

A) An IOException will be thrown.
B) The file, data.dat, will be created.
C) A FileNotFoundException will be thrown.
D) A compiler error will occur.

Question 55

In Windows, which of the following statements will open the file, InputFile.txt, that is in the root directory on the C: drive?

A) FileReader freader = new FileReader("C:\InputFile.txt");
B) FileReader freader = new FileReader("C:\InputFile\txt");
C) FileReader freader = new FileReader("/c/InputFile.txt");
D) FileReader freader = new FileReader("C:\\InputFile.txt");

Question 56

In the following code, assume that inputFile references a Scanner object that has been successfully used to open a file: double totalIncome = 0.0;
While (inputFile.hasNext())
{
Try
{
TotalIncome += inputFile.nextDouble();
}
Catch(InputMismatchException e)
{
System.out.println("Non-numeric data encountered " +
"in the file.");
InputFile.nextLine();
}
Finally
{
TotalIncome = 35.5;
}
}
What will be the value of totalIncome after the following values are read from the file?
2)5
8)5
3)0
5)5
Abc
1)0

A) 19.5.
B) 0.0
C) 35.5
D) 75.0

Question 57

The RandomAccessFile class treats a file as a stream of __________.

A) bytes
B) characters
C) integers
D) data

Question 58

What will the following code display? String input = "99#7";
Int number;
Try
{
Number = Integer.parseInt(input);
}
Catch(NumberFormatException ex)
{
Number = 0;
}
Catch(RuntimeException ex)
{
Number = 1;
}
Catch(Exception ex)
{
Number = -1;
}
System.out.println(number);

A) -1
B) 0
C) 1
D) 99

Question 59

If the code in a method can potentially throw a checked exception, then that method must __________.

A) handle the exception
B) have a throws clause listed in the method header
C) neither of these
D) either of these