public class

PrintStream

extends FilterOutputStream
implements Closeable Appendable

java.lang.Object
↳	java.io.OutputStream
	↳	java.io.FilterOutputStream
		↳	java.io.PrintStream

Class Overview

Wraps an existing OutputStream and provides convenience methods for writing common data types in a human readable format. This is not to be confused with DataOutputStream which is used for encoding common data types so that they can be read back in. No IOException is thrown by this class. Instead, callers should use checkError() to see if a problem has occurred in this stream.

Summary

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Inherited Fields

From class java.io.FilterOutputStream

Public Constructors
	PrintStream(OutputStream out) Constructs a new `PrintStream` with `out` as its target stream.
	PrintStream(OutputStream out, boolean autoflush) Constructs a new `PrintStream` with `out` as its target stream.
	PrintStream(OutputStream out, boolean autoflush, String enc) Constructs a new `PrintStream` with `out` as its target stream and using the character encoding `enc` while writing.
	PrintStream(File file) Constructs a new `PrintStream` with `file` as its target.
	PrintStream(File file, String csn) Constructs a new `PrintStream` with `file` as its target.
	PrintStream(String fileName) Constructs a new `PrintStream` with the file identified by `fileName` as its target.
	PrintStream(String fileName, String csn) Constructs a new `PrintStream` with the file identified by `fileName` as its target.

Public Methods
PrintStream	append(char c) Appends the character `c` to the target stream.
PrintStream	append(CharSequence csq) Appends the character sequence `csq` to the target stream.
PrintStream	append(CharSequence csq, int start, int end) Appends a subsequence of the character sequence `csq` to the target stream.
boolean	checkError() Flushes this stream and returns the value of the error flag.
synchronized void	close() Closes this print stream.
synchronized void	flush() Ensures that all pending data is sent out to the target stream.
PrintStream	format(String format, Object... args) Writes a string formatted by an intermediate `Formatter` to the target stream using the specified format string and arguments.
PrintStream	format(Locale l, String format, Object... args) Writes a string formatted by an intermediate Formatter to this stream using the specified locale, format string and arguments.
void	print(float fnum) Prints the string representation of the specified float to the target stream.
void	print(char ch) Prints the string representation of the specified character to the target stream.
void	print(Object obj) Prints the string representation of the specified object to the target stream.
synchronized void	print(String str) Prints a string to the target stream.
void	print(int inum) Prints the string representation of the specified integer to the target stream.
void	print(double dnum) Prints the string representation of the specified double to the target stream.
void	print(long lnum) Prints the string representation of the specified long to the target stream.
void	print(char[] charArray) Prints the string representation of the specified character array to the target stream.
void	print(boolean bool) Prints the string representation of the specified boolean to the target stream.
PrintStream	printf(Locale l, String format, Object... args) Prints a formatted string.
PrintStream	printf(String format, Object... args) Prints a formatted string.
void	println(double dnum) Prints the string representation of the specified double followed by the system property `"line.separator"` to the target stream.
synchronized void	println(String str) Prints a string followed by the system property `"line.separator"` to the target stream.
void	println(boolean bool) Prints the string representation of the specified boolean followed by the system property `"line.separator"` to the target stream.
void	println(long lnum) Prints the string representation of the specified long followed by the system property `"line.separator"` to the target stream.
void	println(char ch) Prints the string representation of the specified character followed by the system property `"line.separator"` to the target stream.
void	println(float fnum) Prints the string representation of the specified float followed by the system property `"line.separator"` to the target stream.
void	println(char[] charArray) Prints the string representation of the specified character array followed by the system property `"line.separator"` to the target stream.
void	println(Object obj) Prints the string representation of the specified object followed by the system property `"line.separator"` to the target stream.
void	println() Prints the string representation of the system property `"line.separator"` to the target stream.
void	println(int inum) Prints the string representation of the specified integer followed by the system property `"line.separator"` to the target stream.
void	write(byte[] buffer, int offset, int count) Writes `count` bytes from `buffer` starting at `offset` to the target stream.
synchronized void	write(int oneByte) Writes one byte to the target stream.

Protected Methods
void	setError() Sets the error flag of this print stream to `true`.

[Expand]

Inherited Methods

From class java.io.FilterOutputStream

From class java.io.OutputStream

From class java.lang.Object

Object	clone() Creates and returns a copy of this `Object`.
boolean	equals(Object o) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Is called before the object's memory is being reclaimed by the VM.
final Class<? extends Object>	getClass() Returns the unique instance of Class which represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait(long millis, int nanos) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.
final void	wait(long millis) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.
final void	wait() Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object.

From interface java.io.Closeable

From interface java.io.Flushable

From interface java.lang.Appendable

Public Constructors

public PrintStream (OutputStream out)

Constructs a new PrintStream with out as its target stream. By default, the new print stream does not automatically flush its contents to the target stream when a newline is encountered.

Parameters

out	the target output stream.

Throws

NullPointerException	if `out` is `null`.

public PrintStream (OutputStream out, boolean autoflush)

Constructs a new PrintStream with out as its target stream. The parameter autoflush determines if the print stream automatically flushes its contents to the target stream when a newline is encountered.

Parameters

out	the target output stream.
autoflush	indicates whether to flush contents upon encountering a newline sequence.

Throws

NullPointerException	if `out` is `null`.

public PrintStream (OutputStream out, boolean autoflush, String enc)

Constructs a new PrintStream with out as its target stream and using the character encoding enc while writing. The parameter autoflush determines if the print stream automatically flushes its contents to the target stream when a newline is encountered.

Parameters

out	the target output stream.
autoflush	indicates whether or not to flush contents upon encountering a newline sequence.
enc	the non-null string describing the desired character encoding.

Throws

NullPointerException	if `out` or `enc` are `null`.
UnsupportedEncodingException	if the encoding specified by `enc` is not supported.

public PrintStream (File file)

Constructs a new PrintStream with file as its target. The virtual machine's default character set is used for character encoding.

Parameters

file	the target file. If the file already exists, its contents are removed, otherwise a new file is created.

Throws

FileNotFoundException	if an error occurs while opening or creating the target file.
SecurityException	if a security manager exists and it denies writing to the target file.

public PrintStream (File file, String csn)

Constructs a new PrintStream with file as its target. The character set named csn is used for character encoding.

Parameters

file	the target file. If the file already exists, its contents are removed, otherwise a new file is created.
csn	the name of the character set used for character encoding.

Throws

FileNotFoundException	if an error occurs while opening or creating the target file.
NullPointerException	if `csn` is `null`.
SecurityException	if a security manager exists and it denies writing to the target file.
UnsupportedEncodingException	if the encoding specified by `csn` is not supported.

public PrintStream (String fileName)

Constructs a new PrintStream with the file identified by fileName as its target. The virtual machine's default character set is used for character encoding.

Parameters

fileName	the target file's name. If the file already exists, its contents are removed, otherwise a new file is created.

Throws

FileNotFoundException	if an error occurs while opening or creating the target file.
SecurityException	if a security manager exists and it denies writing to the target file.

public PrintStream (String fileName, String csn)

Constructs a new PrintStream with the file identified by fileName as its target. The character set named csn is used for character encoding.

Parameters

fileName	the target file's name. If the file already exists, its contents are removed, otherwise a new file is created.
csn	the name of the character set used for character encoding.

Throws

FileNotFoundException	if an error occurs while opening or creating the target file.
NullPointerException	if `csn` is `null`.
SecurityException	if a security manager exists and it denies writing to the target file.
UnsupportedEncodingException	if the encoding specified by `csn` is not supported.

Public Methods

public PrintStream append (char c)

Appends the character c to the target stream. This method works the same way as print(char).

Parameters

c	the character to append to the target stream.

Returns

this stream.

public PrintStream append (CharSequence csq)

Appends the character sequence csq to the target stream. This method works the same way as PrintStream.print(csq.toString()). If csq is null, then the string "null" is written to the target stream.

Parameters

csq	the character sequence appended to the target stream.

Returns

this stream.

public PrintStream append (CharSequence csq, int start, int end)

Appends a subsequence of the character sequence csq to the target stream. This method works the same way as PrintStream.print(csq.subsequence(start, end).toString()). If csq is null, then the specified subsequence of the string "null" will be written to the target stream.

Parameters

csq	the character sequence appended to the target stream.
start	the index of the first char in the character sequence appended to the target stream.
end	the index of the character following the last character of the subsequence appended to the target stream.

Returns

this stream.

Throws

IndexOutOfBoundsException	if `start > end`, `start < 0`, `end < 0` or either `start` or `end` are greater or equal than the length of `csq`.

public boolean checkError ()

Flushes this stream and returns the value of the error flag.

Returns

true if either an IOException has been thrown previously or if setError() has been called; false otherwise.

public synchronized void close ()

Closes this print stream. Flushes this stream and then closes the target stream. If an I/O error occurs, this stream's error state is set to true.

public synchronized void flush ()

Ensures that all pending data is sent out to the target stream. It also flushes the target stream. If an I/O error occurs, this stream's error state is set to true.

public PrintStream format (String format, Object... args)

Writes a string formatted by an intermediate Formatter to the target stream using the specified format string and arguments. For the locale, the default value of the current virtual machine instance is used.

Parameters

format	the format string used for format(String, Object...).
args	the list of arguments passed to the formatter. If there are more arguments than required by the `format` string, then the additional arguments are ignored.

Returns

this stream.

Throws

IllegalFormatException	if the format string is illegal or incompatible with the arguments, if there are not enough arguments or if any other error regarding the format string or arguments is detected.
NullPointerException	if `format` is `null`.

public PrintStream format (Locale l, String format, Object... args)

Writes a string formatted by an intermediate Formatter to this stream using the specified locale, format string and arguments.

Parameters

l	the locale used in the method. No localization will be applied if `l` is `null`.
format	the format string used for format(String, Object...).
args	the list of arguments passed to the formatter. If there are more arguments than required by the `format` string, then the additional arguments are ignored.

Returns

this stream.

Throws

IllegalFormatException	if the format string is illegal or incompatible with the arguments, if there are not enough arguments or if any other error regarding the format string or arguments is detected.
NullPointerException	if `format` is `null`.

public void print (float fnum)

Prints the string representation of the specified float to the target stream.

Parameters

fnum	the float value to print to the target stream.

public void print (char ch)

Prints the string representation of the specified character to the target stream.

Parameters

ch	the character to print to the target stream.

public void print (Object obj)

Prints the string representation of the specified object to the target stream.

Parameters

obj	the object to print to the target stream.

public synchronized void print (String str)

Prints a string to the target stream. The string is converted to an array of bytes using the encoding chosen during the construction of this stream. The bytes are then written to the target stream with write(int).

If an I/O error occurs, this stream's error state is set to true.

Parameters

str	the string to print to the target stream.

public void print (int inum)

Prints the string representation of the specified integer to the target stream.

Parameters

inum	the integer value to print to the target stream.

public void print (double dnum)

Prints the string representation of the specified double to the target stream.

Parameters

dnum	the double value to print to the target stream.

public void print (long lnum)

Prints the string representation of the specified long to the target stream.

Parameters

lnum	the long value to print to the target stream.

public void print (char[] charArray)

Prints the string representation of the specified character array to the target stream.

Parameters

charArray	the character array to print to the target stream.

public void print (boolean bool)

Prints the string representation of the specified boolean to the target stream.

Parameters

bool	the boolean value to print the target stream.

public PrintStream printf (Locale l, String format, Object... args)

Prints a formatted string. The behavior of this method is the same as this stream's #format(Locale, String, Object...) method.

Parameters

l	the locale used in the method. No localization will be applied if `l` is `null`.
format	the format string used for format(String, Object...).
args	the list of arguments passed to the formatter. If there are more arguments than required by the `format` string, then the additional arguments are ignored.

Returns

this stream.

Throws

IllegalFormatException	if the format string is illegal or incompatible with the arguments, if there are not enough arguments or if any other error regarding the format string or arguments is detected.
NullPointerException	if `format` is `null`.

public PrintStream printf (String format, Object... args)

Prints a formatted string. The behavior of this method is the same as this stream's #format(String, Object...) method. For the locale, the default value of the current virtual machine instance is used.

Parameters

format	the format string used for format(String, Object...).
args	the list of arguments passed to the formatter. If there are more arguments than required by the `format` string, then the additional arguments are ignored.

Returns

this stream.

Throws

IllegalFormatException	if the format string is illegal or incompatible with the arguments, if there are not enough arguments or if any other error regarding the format string or arguments is detected.
NullPointerException	if `format` is `null`.

public void println (double dnum)

Prints the string representation of the specified double followed by the system property "line.separator" to the target stream.

Parameters

dnum	the double value to print to the target stream.

public synchronized void println (String str)

Prints a string followed by the system property "line.separator" to the target stream. The string is converted to an array of bytes using the encoding chosen during the construction of this stream. The bytes are then written to the target stream with write(int).

If an I/O error occurs, this stream's error state is set to true.

Parameters

str	the string to print to the target stream.

public void println (boolean bool)

Prints the string representation of the specified boolean followed by the system property "line.separator" to the target stream.

Parameters

bool	the boolean value to print to the target stream.

public void println (long lnum)

Prints the string representation of the specified long followed by the system property "line.separator" to the target stream.

Parameters

lnum	the long value to print to the target stream.

public void println (char ch)

Prints the string representation of the specified character followed by the system property "line.separator" to the target stream.

Parameters

ch	the character to print to the target stream.

public void println (float fnum)

Prints the string representation of the specified float followed by the system property "line.separator" to the target stream.

Parameters

fnum	the float value to print to the target stream.

public void println (char[] charArray)

Prints the string representation of the specified character array followed by the system property "line.separator" to the target stream.

Parameters

charArray	the character array to print to the target stream.

public void println (Object obj)

Prints the string representation of the specified object followed by the system property "line.separator" to the target stream.

Parameters

obj	the object to print to the target stream.

public void println ()

Prints the string representation of the system property "line.separator" to the target stream.

public void println (int inum)

Prints the string representation of the specified integer followed by the system property "line.separator" to the target stream.

Parameters

inum	the integer value to print to the target stream.

public void write (byte[] buffer, int offset, int count)

Writes count bytes from buffer starting at offset to the target stream. If autoflush is set, this stream gets flushed after writing the buffer.

This stream's error flag is set to true if this stream is closed or an I/O error occurs.

Parameters

buffer	the buffer to be written.
offset	the index of the first byte in `buffer` to write.
count	the number of bytes in `buffer` to write.

Throws

IndexOutOfBoundsException	if `offset < 0` or `count < 0`, or if `offset + count` is bigger than the length of `buffer`.

public synchronized void write (int oneByte)

Writes one byte to the target stream. Only the least significant byte of the integer oneByte is written. This stream is flushed if oneByte is equal to the character '\n' and this stream is set to autoflush.

This stream's error flag is set to true if it is closed or an I/O error occurs.

Parameters

oneByte	the byte to be written

Protected Methods

protected void setError ()

Sets the error flag of this print stream to true.

Interfaces

Classes

Exceptions

PrintStream

Class Overview

Summary

Public Constructors

public PrintStream (OutputStream out)

Parameters

Throws

public PrintStream (OutputStream out, boolean autoflush)

Parameters

Throws

public PrintStream (OutputStream out, boolean autoflush, String enc)

Parameters

Throws

public PrintStream (File file)

Parameters

Throws

public PrintStream (File file, String csn)

Parameters

Throws

public PrintStream (String fileName)

Parameters

Throws

public PrintStream (String fileName, String csn)

Parameters

Throws

Public Methods

public PrintStream append (char c)

Parameters

Returns

public PrintStream append (CharSequence csq)

Parameters

Returns

public PrintStream append (CharSequence csq, int start, int end)

Parameters

Returns

Throws

public boolean checkError ()

Returns

See Also

public synchronized void close ()

public synchronized void flush ()

public PrintStream format (String format, Object... args)

Parameters

Returns

Throws

public PrintStream format (Locale l, String format, Object... args)

Parameters

Returns

Throws

public void print (float fnum)

Parameters

See Also

public void print (char ch)

Parameters

See Also

public void print (Object obj)

Parameters

See Also

public synchronized void print (String str)

Parameters

See Also

public void print (int inum)

Parameters

See Also

public void print (double dnum)

Parameters

See Also

public void print (long lnum)

Parameters

See Also

public void print (char[] charArray)

Parameters

See Also

public void print (boolean bool)

Parameters

See Also

public PrintStream printf (Locale l, String format, Object... args)