Java ch 15 Exercises
True
'Files static' method 'exists' receives a Path and determines whether it exists (either as a file or as a directory) on a disk. True False
opens
A Java program _____________ a file by creating an object and associating a stream of bytes or characters with it.
True
A Java program simply receives an indication from the operating system when it reaches the end of the stream
LineNumberReader
A ______________ (a subclass of Buffered-Reader) is a buffered character stream that keeps track of the number of lines read.
FilterInputStream, FilterOutputStream
A ______________ filters an InputStream, and a _______________ filters an OutputStream.
relative path
A _______________ is "relative" to another directory—for example, a path relative to the directory in which the application began executing.
serialized object
A ________________ is represented by XML that includes the object's data
separator character
A __________________ is used to separate directories and files in a path.
SecurityException
A ____________________ occurs if the user does not have permission to write data to the file.
PrintStream
A _____________________ (a subclass of FilterOutputStream) performs text output to the specified stream.
NoSuchElementException
A __________________________ occurs if the data being read by a Scanner method is in the wrong format or if there is no more data to input.
FileNotFoundException
A __________________________ occurs if the file does not exist and a new file cannot be created.
Uniform Resource Identifier (URI), Uniform Resource Locators (URLs)
A ______________________________ is a more general form of the ________________________________ that are used to locate websites.
flush
A partially filled buffer can be forced out to the device at any time by invoking the stream object's ___________ method.
deserialized
After a serialized object has been written into a file, it can be read from the file and _________________—that is, the XML that represents the object and its data can be used to recreate the object in memory\
InputStreamReader.
An InputStream can be converted to a Reader via class ______________
OutputStreamWriter.
An OuputStream can be converted to a Writer via class ___________________
absolute path, root directory
An ___________ contains all directories, starting with the ______________, that lead to a specific file or directory.
True
An absolute path contains all the directories, starting with the root directory, that lead to a specific file or directory. True False
@XMLElement, javax.xml.bind.annotation
Annotation______________ (line 9; package _______________________) indicates that the private instance variable should be serialized
Formatter
Character-based input and output can be performed with classes Scanner and ___________.
False Class Formatter contains method format, which enables formatted data to be output to the screen or to a file.
Class Formatter contains method printf, which enables formatted data to be output to the screen or to a file. True False
False. Class Scanner does not allow repositioning to the beginning of the file.
Class Scanner does allow repositioning to the beginning of the file.
setIn, setOut, setErr
Class System provides methods __________, ____________ and _____________ to redirect the standard input, output and error streams, respectively.
PipedReader, PipedWriter
Class _____________ and class ________________ implement piped-character streams for transfering data between threads.
Formatter
Class _____________ enables formatted data to be output to any text-based stream in a manner similar to method System.out.printf.
StringReader, StringWriter
Class _______________ and ___________ read characters from and write characters to Strings.
Scanner
Class _______________ is used extensively to input data from the keyboard. This class can also read data from a file.
java.io.PrintWriter
Class _________________ outputs data to a text file.
FileChooserTest
Class ___________________ launches the JavaFX application
FileChooserTestController
Class ______________________ responds to the Buttons' events
DataOutputStream
Classes ___________ (a subclass of FilterOutputStream) and RandomAccessFile each implement this interface to write primitive-type values as bytes.
CharArrayReader, CharArrayWriter
Classes ______________ and ____________________ read and write, respectively, a stream of characters to a char array.
BufferedReader, BufferedWriter
Classes ________________ (a subclass of abstract class Reader) and ________________ (a subclass of abstract class Writer) enable buffering for character-based streams.
DataInputStream
Classes ________________ and RandomAccessFile each implement this interface to read sets of bytes and process them as primitive-type values.
secondary storage devices
Computers store files on _______________ such as, hard disks, flash drives, DVDs and more.
persistent data
Data maintained in files is ____________ because it exists beyond the duration of program execution.
temporary
Data stored in variables and arrays is ____________. It's lost when a local variable goes out of scope or when the program terminates
redirected
Each stream can be _____________.
end-of-file marker
Every operating system provides a mechanism to determine the end of a file, such as an ____________________ or a count of the total bytes in the file that is recorded in a system-maintained administrative data structure.
False. File streams can be used to input and output data as bytes or characters.
File streams cannot be used to input and output data as bytes or characters.
text files
Files created using character-based streams are referred to as ___________. Text files can be read by text editors.
size
Files static method ___________ receives a Path and returns a long representing number of bytes in a file or directory.
newBufferedWriter, BufferedWriter
Files static method _____________, which receives a Path specifying the file to open for writing ("clients.xml") and—if the file exists—returns a __________________ that class JAXB will use to write text to the file
getLastModifiedTime
Files static method ______________ receives a Path and returns a FileTime indicating when the file was last modified.
isDirectory
Files static method _______________ receives a Path and returns a boolean indicating whether that Path represents a directory on disk.
files
For long-term retention of data, computers use ____________.
close
Formatter method ____________ closes the file.
format
Formatter method _______________ works like System.out.printf
IllegalStateException
If a Scanner is closed before data is input, an _______________________ occurs.
truncated.
If an existing file is opened, its contents are ______________.
new DirectoryStream
If the Path represents a directory use File static method _______________.
XML serialization, marshaling
JAXB enables you to perform _______________—which JAXB refers to as ________________.
unmarshal
JAXB static method ________________ reads the contents of clients.xml and convert the XML into an Accounts object
marshal
JAXB static method _________________ to serialize as XML the Accounts object containing the List<Account>
POJOs (plain old Java objects)
JAXB works with _______________________—no special superclasses or interfaces are required for XML-serialization support
java.io , java.nio.
Java programs perform file processing by using classes from package _____________ and the subpackages of _____________.
stream of bytes
Java views each file as a sequential ____________.
FileChooser, DirectoryChooser
JavaFX classes __________ and _____________________ (package javafx.stage) display dialogs that enable the user to select a file or directory, respectively
getFileName
Path method ________ returns the String name of a file or directory without any location information.
toAbsolutePath
Path method _____________ converts the Path on which it's called to an absolute path.
toString
Path method _____________ returns a String representing the Path.
isAbsolute
Path method ________________ returns a boolean indicating whether that Path represents an absolute path to a file or directory.
Reader, Writer
The _____________ and ______________ abstract classes are Unicode two-byte, character-based streams.
batch , shell script
The argument is useful if the program is executed from a __________ file on Windows or a _____________ on UNIX/Linux/Mac OS X.
logical output operations.
The output operations directed to the output buffer in memory are often called _______________________.
newBufferedReader, Buffered-Reader
The program opens the file for input by calling Files static method________________, which receives a Path specifying the file to open and, if the file exists and no exceptions occur, returns a _________________ for reading from the file.
physical output operation
Transfer to the output device is performed in one large ______________ each time the buffer fills.
True
When reading data from a file using class Scanner, if you wish to read data in the file multiple times, the file must be closed and reopened to read from the beginning of the file. True False
BufferedOutputStream, buffer
With a ________________, each output operation is directed to a ______________ larger enough to hold the data of many output operations
Scanner inTransaction = new Scanner(Paths.get("trans.txt"));
Write a statement tha opens files "trans.txt" for input-use Scanner variable inTransaction.
Formatter outNewMaster = new Formatter("newmast.txt");
Write a statement that opens file "newmast.txt" for output (and creation)-user formatter variable outNewMaster.
Scanner oldmastInput = new Scanner(Paths.get("oldmas.txt"));
Write a statement that opens file "oldmast.txt" for input-use Scanner variable inOldMaster
Accounts account = JAXB.unmarshal(reader, Accounts.class);
Write a statement that performs the following tasks: Input an XML serialized object into an Accounts object names accounts using a BufferedReader name reader
JAXB.marshal(accounts, writer);
Write a statement that performs the following tasks: Output an Accounts object names accounts using XML serialization and a BufferedWriter name writer
Account account = new Account(); account.setAccount(inOldMaster.next()); account.setFirstName(inOldMaster.next()); account.setLastName(inOldMaster.next()); account.setBalance(inOldMaster.nextDouble());
Write the statements needed to read a record form the file "oldmast.txt". Use the data to create an object of class Account-use Scanner variable inOldMaster. Assume that class Account is the same as the Account class in fig 15.9
TransactionRecord transaction = new Transactions(); transaction.setAccount(inTransaction.nextInt()); transaction.setAmount(inTransaction.nextDouble());
Write the statements needed to read a record fromt he file "trans.txt". Th record is an object of class TransactionRecord-use Scanner variable inTransaction. Assume tha 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.
False XML files are both computer and machine readable
XML files are not human readable in a text editor. True False
False These three streams are created for you when a Java application begins executing.
You must explicitly create the stream objects System.in, System.out and System.err. True False
Character-based streams
____________ output and input data as a sequence of characters in which every character is two bytes—the number of bytes for a given value depends on the number of characters in that value.
Pipes
______________ are synchronized communication channels between threads.
Binary files
_______________ are read by programs that understand the specific content of the file and the ordering of that content.
Byte-based streams
________________ output and input data in its binary format—a char is two bytes, an int is four bytes, a double is eight bytes, etc.
Filtering
_________________ means simply that the filter stream provides additional functionality, such as aggregating bytes into meaningful primitive-type units.
Sequential files
__________________ store records in order by the record-key field.
Buffering
____________________ is an I/O-performance-enhancement technique.
InputStream, OutputStream
______________________ and _____________ are abstract classes that declare methods for performing byte-based input and output, respectively.
PipedOutputStream (a subclass of OutputStream), PipedInputStream (a subclass of InputStream)
______________________________________ and ________________ establish pipes between two threads in a program.
FilterInputStream and FilterOutputStream
______________________________________________ are typically used as superclasses, so some of their filtering capabilities are provided by their subclasses.
DirectoryStream interface
_________________—Objects of classes that implement this interface enable a program to iterate through the contents of a directory.
Path interface
______________—Objects of classes that implement this interface represent the location of a file or directory. Path objects do not open files or provide any file-processing capabilities.
Paths class
_____________—Provides static methods used to get a Path object representing a file or directory location.
Files class
____________—Provides static methods for common file and directory manipulations, such as copying files; creating and deleting files and directories; getting information about files and directories; reading the contents of files; getting objects that allow you to manipulate the contents of files and directories; and more
get
class static method ____________ of class Paths to convert a String representing in a file's or directory's location into a Path object.
System.exit
static method ________________ terminates an application.
FormatterClosedException
that occurs if the Formatter object is closed when you attempt to use it.
