student.testingsupport

Class PrintStreamWithHistory

java.lang.Object

java.io.OutputStream

java.io.FilterOutputStream

java.io.PrintStream

student.testingsupport.PrintStreamWithHistory

All Implemented Interfaces:

Closeable, Flushable, Appendable, AutoCloseable

public class PrintStreamWithHistory
extends PrintStream

An enhanced version of PrintStream that provides for a history recall function and some other features making I/O testing a bit easier to perform. See the documentation for PrintStream for more thorough details on what methods are provided.

Version:

$Revision: 1.5 $, $Date: 2015/08/20 13:01:51 $

Author:

Stephen Edwards, Last changed by $Author: stedwar2 $

Field Summary

Fields inherited from class java.io.FilterOutputStream

out

Constructor Summary

Constructors

Constructor and Description
PrintStreamWithHistory(File file) Creates a new print stream, without automatic line flushing, with the specified file.
PrintStreamWithHistory(File file, String csn) Creates a new print stream, without automatic line flushing, with the specified file and charset.
PrintStreamWithHistory(OutputStream out) Create a new print stream.
PrintStreamWithHistory(OutputStream out, boolean autoFlush) Create a new print stream.
PrintStreamWithHistory(OutputStream out, boolean autoFlush, String encoding) Create a new print stream.
PrintStreamWithHistory(String fileName) Creates a new print stream, without automatic line flushing, with the specified file name.
PrintStreamWithHistory(String fileName, String csn) Creates a new print stream, without automatic line flushing, with the specified file name and charset.

Method Summary

Modifier and Type	Method and Description
void	clearHistory() Reset this object's history to be empty, just as when the object was first created.
String	getHistory() Retrieve the text history of what has been sent to this PrintStream.
boolean	getNormalizeLineEndings() Returns whether this object's history has normalized unix-style line endings, or the raw line endings generated by printing.
void	setNormalizeLineEndings(boolean value) Set whether this object's history will have normalized unix-style line endings, or the raw line endings generated by printing.
void	write(byte[] buf, int off, int len) Write len bytes from the specified byte array starting at offset off to this stream.
void	write(int b) Write the specified byte to this stream.

Methods inherited from class java.io.PrintStream

append, append, append, checkError, clearError, close, flush, format, format, print, print, print, print, print, print, print, print, print, printf, printf, println, println, println, println, println, println, println, println, println, println, setError

Methods inherited from class java.io.FilterOutputStream

write

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

PrintStreamWithHistory

public PrintStreamWithHistory(OutputStream out)

Create a new print stream. This stream will not flush automatically.

Parameters:

out - The output stream to which values and objects will be printed

See Also:

PrintWriter.PrintWriter(java.io.OutputStream)

PrintStreamWithHistory

public PrintStreamWithHistory(OutputStream out,
                              boolean autoFlush)

Create a new print stream.

Parameters:

out - The output stream to which values and objects will be printed

autoFlush - A boolean; if true, the output buffer will be flushed whenever a byte array is written, one of the println methods is invoked, or a newline character or byte ('\n') is written

See Also:

PrintWriter.PrintWriter(java.io.OutputStream, boolean)

PrintStreamWithHistory

public PrintStreamWithHistory(OutputStream out,
                              boolean autoFlush,
                              String encoding)
                       throws UnsupportedEncodingException

Create a new print stream.

Parameters:

out - The output stream to which values and objects will be printed

autoFlush - A boolean; if true, the output buffer will be flushed whenever a byte array is written, one of the println methods is invoked, or a newline character or byte ('\n') is written

encoding - The name of a supported character encoding

Throws:

UnsupportedEncodingException - If the named encoding is not supported

PrintStreamWithHistory

public PrintStreamWithHistory(String fileName)
                       throws FileNotFoundException

Creates a new print stream, without automatic line flushing, with the specified file name. This convenience constructor creates the necessary intermediate OutputStreamWriter, which will encode characters using the default charset for this instance of the Java virtual machine.

Parameters:

fileName - The name of the file to use as the destination of this print stream. If the file exists, then it will be truncated to zero size; otherwise, a new file will be created. The output will be written to the file and is buffered.

Throws:

FileNotFoundException - If the given file object does not denote an existing, writable regular file and a new regular file of that name cannot be created, or if some other error occurs while opening or creating the file

SecurityException - If a security manager is present and checkWrite(fileName) denies write access to the file

Since:

1.5

PrintStreamWithHistory

public PrintStreamWithHistory(String fileName,
                              String csn)
                       throws FileNotFoundException,
                              UnsupportedEncodingException

Creates a new print stream, without automatic line flushing, with the specified file name and charset. This convenience constructor creates the necessary intermediate OutputStreamWriter, which will encode characters using the provided charset.

Parameters:

fileName - The name of the file to use as the destination of this print stream. If the file exists, then it will be truncated to zero size; otherwise, a new file will be created. The output will be written to the file and is buffered.

csn - The name of a supported charset

Throws:

FileNotFoundException - If the given file object does not denote an existing, writable regular file and a new regular file of that name cannot be created, or if some other error occurs while opening or creating the file

SecurityException - If a security manager is present and checkWrite(fileName) denies write access to the file

UnsupportedEncodingException - If the named charset is not supported

Since:

1.5

PrintStreamWithHistory

public PrintStreamWithHistory(File file)
                       throws FileNotFoundException

Creates a new print stream, without automatic line flushing, with the specified file. This convenience constructor creates the necessary intermediate OutputStreamWriter, which will encode characters using the default charset for this instance of the Java virtual machine.

Parameters:

file - The file to use as the destination of this print stream. If the file exists, then it will be truncated to zero size; otherwise, a new file will be created. The output will be written to the file and is buffered.

Throws:

FileNotFoundException - If the given file object does not denote an existing, writable regular file and a new regular file of that name cannot be created, or if some other error occurs while opening or creating the file

SecurityException - If a security manager is present and checkWrite(file.getPath()) denies write access to the file

Since:

1.5

PrintStreamWithHistory

public PrintStreamWithHistory(File file,
                              String csn)
                       throws FileNotFoundException,
                              UnsupportedEncodingException

Creates a new print stream, without automatic line flushing, with the specified file and charset. This convenience constructor creates the necessary intermediate OutputStreamWriter, which will encode characters using the provided charset.

Parameters:

file - The file to use as the destination of this print stream. If the file exists, then it will be truncated to zero size; otherwise, a new file will be created. The output will be written to the file and is buffered.

csn - The name of a supported charset

Throws:

FileNotFoundException - If the given file object does not denote an existing, writable regular file and a new regular file of that name cannot be created, or if some other error occurs while opening or creating the file

SecurityException - If a security manager is presentand checkWrite(file.getPath()) denies write access to the file

UnsupportedEncodingException - If the named charset is not supported

Since:

1.5

Method Detail

getHistory

public String getHistory()

Retrieve the text history of what has been sent to this PrintStream. This will include all text printed through this object. The clearHistory() method resets the history to be empty, just as when the object was first created. Note that newline characters in the history are always represented by '\n', regardless of what value the system line.separator property has.

Returns:

all the text sent to this PrintStream

clearHistory

public void clearHistory()

Reset this object's history to be empty, just as when the object was first created. You can access the history using getHistory().

setNormalizeLineEndings

public void setNormalizeLineEndings(boolean value)

Set whether this object's history will have normalized unix-style line endings, or the raw line endings generated by printing. The default for this is true, so history values will automatically be normalized unless this method is used to change that behavior.

Parameters:

value - If true, the retrieved history will have all line endings automatically standardized to unix-style ("\n") line endings; if fase, the retrieved history will be presented without any modifications, using whatever (platform-specific) line endings were printed to this object.

getNormalizeLineEndings

public boolean getNormalizeLineEndings()

Returns whether this object's history has normalized unix-style line endings, or the raw line endings generated by printing. The default behavior is to normalize line endings.

Returns:

True if line endings will be normalized in the history.

write

public void write(int b)

Write the specified byte to this stream. If the byte is a newline and automatic flushing is enabled then the flush method will be invoked.

Note that the byte is written as given; to write a character that will be translated according to the platform's default character encoding, use the print(char) or println(char) methods.

Overrides:

write in class PrintStream

Parameters:

b - The byte to be written

See Also:

PrintStream.print(char), PrintStream.println(char)

write

public void write(byte[] buf,
                  int off,
                  int len)

Write len bytes from the specified byte array starting at offset off to this stream. If automatic flushing is enabled then the flush method will be invoked.

Note that the bytes will be written as given; to write characters that will be translated according to the platform's default character encoding, use the print(char) or println(char) methods.

Overrides:

write in class PrintStream

Parameters:

buf - A byte array

off - Offset from which to start taking bytes

len - Number of bytes to write