to top
Android APIs
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

[Expand]
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 charsetName)
Constructs a new PrintStream with out as its target stream and using the character encoding charsetName while writing.
PrintStream( File file)
Constructs a new PrintStream with file as its target.
PrintStream( File file, String charsetName)
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 charsetName)
Constructs a new PrintStream with the file identified by fileName as its target.
Public Methods
PrintStream append(char c)
Appends the char c.
PrintStream append( CharSequence charSequence, int start, int end)
Appends a subsequence of CharSequence charSequence, or "null".
PrintStream append( CharSequence charSequence)
Appends the CharSequence charSequence, or "null".
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( 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.
PrintStream format( String format, Object... args)
Formats args according to the format string format, and writes the result to this stream.
void print(float f)
Prints the string representation of the float f.
void print(double d)
Prints the string representation of the double d.
synchronized void print( String str)
Prints a string to the target stream.
void print( Object o)
Prints the string representation of the Object o, or "null".
void print(char c)
Prints the string representation of the char c.
void print(char[] chars)
Prints the string representation of the character array chars.
void print(long l)
Prints the string representation of the long l.
void print(int i)
Prints the string representation of the int i.
void print(boolean b)
Prints the string representation of the boolean b.
PrintStream printf( Locale l, String format, Object... args)
Prints a formatted string.
PrintStream printf( String format, Object... args)
Prints a formatted string.
void println()
Prints a newline.
void println(float f)
Prints the string representation of the float f followed by a newline.
void println(int i)
Prints the string representation of the int i followed by a newline.
void println(long l)
Prints the string representation of the long l followed by a newline.
void println( Object o)
Prints the string representation of the Object o, or "null", followed by a newline.
void println(char[] chars)
Prints the string representation of the character array chars followed by a newline.
synchronized void println( String str)
Prints a string followed by a newline.
void println(char c)
Prints the string representation of the char c followed by a newline.
void println(double d)
Prints the string representation of the double d followed by a newline.
void println(boolean b)
Prints the string representation of the boolean b followed by a newline.
synchronized void write(int oneByte)
Writes one byte to the target stream.
void write(byte[] buffer, int offset, int length)
Writes count bytes from buffer starting at offset to the target stream.
Protected Methods
void clearError()
Sets the error state of the stream to false.
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
From interface java.io.Closeable
From interface java.io.Flushable
From interface java.lang.Appendable

Public Constructors

public PrintStream (OutputStream out)

Added in API level 1

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)

Added in API level 1

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 charsetName)

Added in API level 1

Constructs a new PrintStream with out as its target stream and using the character encoding charsetName 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.
charsetName the non-null string describing the desired character encoding.
Throws
NullPointerException if out or charsetName are null.
UnsupportedEncodingException if the encoding specified by charsetName is not supported.

public PrintStream (File file)

Added in API level 1

Constructs a new PrintStream with file as its target. The VM'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.

public PrintStream (File file, String charsetName)

Added in API level 1

Constructs a new PrintStream with file as its target. The character set named charsetName 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.
charsetName 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 charsetName is null.
UnsupportedEncodingException if the encoding specified by charsetName is not supported.

public PrintStream (String fileName)

Added in API level 1

Constructs a new PrintStream with the file identified by fileName as its target. The VM'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.

public PrintStream (String fileName, String charsetName)

Added in API level 1

Constructs a new PrintStream with the file identified by fileName as its target. The character set named charsetName 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.
charsetName 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 charsetName is null.
UnsupportedEncodingException if the encoding specified by charsetName is not supported.

Public Methods

public PrintStream append (char c)

Added in API level 1

Appends the char c.

Parameters
c the character to append.
Returns
  • this stream.

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

Added in API level 1

Appends a subsequence of CharSequence charSequence, or "null".

Parameters
charSequence 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 charSequence.

public PrintStream append (CharSequence charSequence)

Added in API level 1

Appends the CharSequence charSequence, or "null".

Parameters
charSequence the character sequence to append.
Returns
  • this stream.

public boolean checkError ()

Added in API level 1

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.
See Also

public synchronized void close ()

Added in API level 1

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 ()

Added in API level 1

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

Added in API level 1

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 (see format(String, Object...))
args the list of arguments passed to the formatter. If there are more arguments than required by format, 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 == null

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

Added in API level 1

Formats args according to the format string format, and writes the result to this stream. This method uses the user's default locale. See "Be wary of the default locale".

Parameters
format the format string (see format(String, Object...))
args the list of arguments passed to the formatter. If there are more arguments than required by format, 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 == null

public void print (float f)

Added in API level 1

Prints the string representation of the float f.

public void print (double d)

Added in API level 1

Prints the string representation of the double d.

public synchronized void print (String str)

Added in API level 1

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.
See Also

public void print (Object o)

Added in API level 1

Prints the string representation of the Object o, or "null".

public void print (char c)

Added in API level 1

Prints the string representation of the char c.

public void print (char[] chars)

Added in API level 1

Prints the string representation of the character array chars.

public void print (long l)

Added in API level 1

Prints the string representation of the long l.

public void print (int i)

Added in API level 1

Prints the string representation of the int i.

public void print (boolean b)

Added in API level 1

Prints the string representation of the boolean b.

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

Added in API level 1

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 (see format(String, Object...))
args the list of arguments passed to the formatter. If there are more arguments than required by format, 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 == null.

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

Added in API level 1

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

The Locale used is the user's default locale. See "Be wary of the default locale".

Parameters
format the format string (see format(String, Object...))
args the list of arguments passed to the formatter. If there are more arguments than required by format, 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 == null

public void println ()

Added in API level 1

Prints a newline.

public void println (float f)

Added in API level 1

Prints the string representation of the float f followed by a newline.

public void println (int i)

Added in API level 1

Prints the string representation of the int i followed by a newline.

public void println (long l)

Added in API level 1

Prints the string representation of the long l followed by a newline.

public void println (Object o)

Added in API level 1

Prints the string representation of the Object o, or "null", followed by a newline.

public void println (char[] chars)

Added in API level 1

Prints the string representation of the character array chars followed by a newline.

public synchronized void println (String str)

Added in API level 1

Prints a string followed by a newline. 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.
See Also

public void println (char c)

Added in API level 1

Prints the string representation of the char c followed by a newline.

public void println (double d)

Added in API level 1

Prints the string representation of the double d followed by a newline.

public void println (boolean b)

Added in API level 1

Prints the string representation of the boolean b followed by a newline.

public synchronized void write (int oneByte)

Added in API level 1

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

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

Added in API level 1

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.
length 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.
See Also

Protected Methods

protected void clearError ()

Added in API level 9

Sets the error state of the stream to false.

protected void setError ()

Added in API level 1

Sets the error flag of this print stream to true.

No examples for this method.
Frequently called with: [Clear]
Portions of this page are reproduced from work created and shared by the Android Open Source Project and used according to terms described in the Creative Commons 2.5 Attribution License. The original page is available here.