java.io
Class PrintStream

java.lang.Object
  extended by java.io.OutputStream
      extended by java.io.FilterOutputStream
          extended by java.io.PrintStream
All Implemented Interfaces:
Closeable, Flushable, Appendable
Direct Known Subclasses:
LogStream

public class PrintStream
extends FilterOutputStream
implements Appendable

This class prints Java primitive values and object to a stream as text. None of the methods in this class throw an exception. However, errors can be detected by calling the checkError() method. Additionally, this stream can be designated as "autoflush" when created so that any writes are automatically flushed to the underlying output sink when the current line is terminated.

This class converts char's into byte's using the system default encoding.


Field Summary
 
Fields inherited from class java.io.FilterOutputStream
out
 
Constructor Summary
PrintStream(File file)
          This method initializes a new PrintStream object to write to the specified output File.
PrintStream(File file, String encoding)
          This method initializes a new PrintStream object to write to the specified output File.
PrintStream(OutputStream out)
          This method intializes a new PrintStream object to write to the specified output sink.
PrintStream(OutputStream out, boolean auto_flush)
          This method intializes a new PrintStream object to write to the specified output sink.
PrintStream(OutputStream out, boolean auto_flush, String encoding)
          This method intializes a new PrintStream object to write to the specified output sink.
PrintStream(String fileName)
          This method initializes a new PrintStream object to write to the specified output File.
PrintStream(String fileName, String encoding)
          This method initializes a new PrintStream object to write to the specified output File.
 
Method Summary
 PrintStream append(char c)
          Appends the Unicode character, c, to this Appendable object.
 PrintStream append(CharSequence cs)
          Appends the specified sequence of Unicode characters to this Appendable object.
 PrintStream append(CharSequence cs, int start, int end)
          Appends the specified subsequence of Unicode characters to this Appendable object, starting and ending at the specified positions within the sequence.
 boolean checkError()
          This method checks to see if an error has occurred on this stream.
 void close()
          This method closes this stream and all underlying streams.
 void flush()
          This method flushes any buffered bytes to the underlying stream and then flushes that stream as well.
 PrintStream format(Locale locale, String format, Object... args)
           
 PrintStream format(String format, Object... args)
           
 void print(boolean bool)
          This methods prints a boolean value to the stream.
 void print(char ch)
          This method prints a char to the stream.
 void print(char[] charArray)
          This method prints an array of characters to the stream.
 void print(double dnum)
          This method prints a double to the stream.
 void print(float fnum)
          This method prints a float to the stream.
 void print(int inum)
          This method prints an integer to the stream.
 void print(long lnum)
          This method prints a long to the stream.
 void print(Object obj)
          This method prints an Object to the stream.
 void print(String str)
          This method prints a String to the stream.
 PrintStream printf(Locale locale, String format, Object... args)
           
 PrintStream printf(String format, Object... args)
           
 void println()
          This method prints a line separator sequence to the stream.
 void println(boolean bool)
          This methods prints a boolean value to the stream.
 void println(char ch)
          This method prints a char to the stream.
 void println(char[] charArray)
          This method prints an array of characters to the stream.
 void println(double dnum)
          This method prints a double to the stream.
 void println(float fnum)
          This method prints a float to the stream.
 void println(int inum)
          This method prints an integer to the stream.
 void println(long lnum)
          This method prints a long to the stream.
 void println(Object obj)
          This method prints an Object to the stream.
 void println(String str)
          This method prints a String to the stream.
protected  void setError()
          This method can be called by subclasses to indicate that an error has occurred and should be reported by checkError.
 void write(byte[] buffer, int offset, int len)
          This method writes len bytes from the specified array starting at index offset into the array.
 void write(int oneByte)
          This method writes a byte of data to the stream.
 
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

PrintStream

public PrintStream(OutputStream out)
This method intializes a new PrintStream object to write to the specified output sink.

Parameters:
out - The OutputStream to write to.

PrintStream

public PrintStream(OutputStream out,
                   boolean auto_flush)
This method intializes a new PrintStream object to write to the specified output sink. This constructor also allows "auto-flush" functionality to be specified where the stream will be flushed after every print or println call, when the write methods with array arguments are called, or when a single new-line character is written.

Parameters:
out - The OutputStream to write to.
auto_flush - true to flush the stream after every line, false otherwise

PrintStream

public PrintStream(File file)
            throws FileNotFoundException
This method initializes a new PrintStream object to write to the specified output File. Doesn't autoflush.

Parameters:
file - The File to write to.
Throws:
FileNotFoundException - if an error occurs while opening the file.
Since:
1.5

PrintStream

public PrintStream(File file,
                   String encoding)
            throws FileNotFoundException,
                   UnsupportedEncodingException
This method initializes a new PrintStream object to write to the specified output File. Doesn't autoflush.

Parameters:
file - The File to write to.
encoding - The name of the character encoding to use for this object.
Throws:
FileNotFoundException - If an error occurs while opening the file.
UnsupportedEncodingException - If the charset specified by encoding is invalid.
Since:
1.5

PrintStream

public PrintStream(String fileName)
            throws FileNotFoundException
This method initializes a new PrintStream object to write to the specified output File. Doesn't autoflush.

Parameters:
fileName - The name of the File to write to.
Throws:
FileNotFoundException - if an error occurs while opening the file,
Since:
1.5

PrintStream

public PrintStream(String fileName,
                   String encoding)
            throws FileNotFoundException,
                   UnsupportedEncodingException
This method initializes a new PrintStream object to write to the specified output File. Doesn't autoflush.

Parameters:
fileName - The name of the File to write to.
encoding - The name of the character encoding to use for this object.
Throws:
FileNotFoundException - if an error occurs while opening the file.
UnsupportedEncodingException - If the charset specified by encoding is invalid.
Since:
1.5

PrintStream

public PrintStream(OutputStream out,
                   boolean auto_flush,
                   String encoding)
            throws UnsupportedEncodingException
This method intializes a new PrintStream object to write to the specified output sink. This constructor also allows "auto-flush" functionality to be specified where the stream will be flushed after every print or println call, when the write methods with array arguments are called, or when a single new-line character is written.

Parameters:
out - The OutputStream to write to.
auto_flush - true to flush the stream after every line, false otherwise
encoding - The name of the character encoding to use for this object.
Throws:
UnsupportedEncodingException
Method Detail

checkError

public boolean checkError()
This method checks to see if an error has occurred on this stream. Note that once an error has occurred, this method will continue to report true forever for this stream. Before checking for an error condition, this method flushes the stream.

Returns:
true if an error has occurred, false otherwise

setError

protected void setError()
This method can be called by subclasses to indicate that an error has occurred and should be reported by checkError.


close

public void close()
This method closes this stream and all underlying streams.

Specified by:
close in interface Closeable
Overrides:
close in class FilterOutputStream

flush

public void flush()
This method flushes any buffered bytes to the underlying stream and then flushes that stream as well.

Specified by:
flush in interface Flushable
Overrides:
flush in class FilterOutputStream

print

public void print(boolean bool)
This methods prints a boolean value to the stream. true values are printed as "true" and false values are printed as "false".

Parameters:
bool - The boolean value to print

print

public void print(int inum)
This method prints an integer to the stream. The value printed is determined using the String.valueOf() method.

Parameters:
inum - The int value to be printed

print

public void print(long lnum)
This method prints a long to the stream. The value printed is determined using the String.valueOf() method.

Parameters:
lnum - The long value to be printed

print

public void print(float fnum)
This method prints a float to the stream. The value printed is determined using the String.valueOf() method.

Parameters:
fnum - The float value to be printed

print

public void print(double dnum)
This method prints a double to the stream. The value printed is determined using the String.valueOf() method.

Parameters:
dnum - The double value to be printed

print

public void print(Object obj)
This method prints an Object to the stream. The actual value printed is determined by calling the String.valueOf() method.

Parameters:
obj - The Object to print.

print

public void print(String str)
This method prints a String to the stream. The actual value printed depends on the system default encoding.

Parameters:
str - The String to print.

print

public void print(char ch)
This method prints a char to the stream. The actual value printed is determined by the character encoding in use.

Parameters:
ch - The char value to be printed

print

public void print(char[] charArray)
This method prints an array of characters to the stream. The actual value printed depends on the system default encoding.

Parameters:
charArray - The array of characters to print.

println

public void println()
This method prints a line separator sequence to the stream. The value printed is determined by the system property line.separator and is not necessarily the Unix '\n' newline character.


println

public void println(boolean bool)
This methods prints a boolean value to the stream. true values are printed as "true" and false values are printed as "false".

This method prints a line termination sequence after printing the value.

Parameters:
bool - The boolean value to print

println

public void println(int inum)
This method prints an integer to the stream. The value printed is determined using the String.valueOf() method.

This method prints a line termination sequence after printing the value.

Parameters:
inum - The int value to be printed

println

public void println(long lnum)
This method prints a long to the stream. The value printed is determined using the String.valueOf() method.

This method prints a line termination sequence after printing the value.

Parameters:
lnum - The long value to be printed

println

public void println(float fnum)
This method prints a float to the stream. The value printed is determined using the String.valueOf() method.

This method prints a line termination sequence after printing the value.

Parameters:
fnum - The float value to be printed

println

public void println(double dnum)
This method prints a double to the stream. The value printed is determined using the String.valueOf() method.

This method prints a line termination sequence after printing the value.

Parameters:
dnum - The double value to be printed

println

public void println(Object obj)
This method prints an Object to the stream. The actual value printed is determined by calling the String.valueOf() method.

This method prints a line termination sequence after printing the value.

Parameters:
obj - The Object to print.

println

public void println(String str)
This method prints a String to the stream. The actual value printed depends on the system default encoding.

This method prints a line termination sequence after printing the value.

Parameters:
str - The String to print.

println

public void println(char ch)
This method prints a char to the stream. The actual value printed is determined by the character encoding in use.

This method prints a line termination sequence after printing the value.

Parameters:
ch - The char value to be printed

println

public void println(char[] charArray)
This method prints an array of characters to the stream. The actual value printed depends on the system default encoding.

This method prints a line termination sequence after printing the value.

Parameters:
charArray - The array of characters to print.

write

public void write(int oneByte)
This method writes a byte of data to the stream. If auto-flush is enabled, printing a newline character will cause the stream to be flushed after the character is written.

Overrides:
write in class FilterOutputStream
Parameters:
oneByte - The byte to be written

write

public void write(byte[] buffer,
                  int offset,
                  int len)
This method writes len bytes from the specified array starting at index offset into the array.

Overrides:
write in class FilterOutputStream
Parameters:
buffer - The array of bytes to write
offset - The index into the array to start writing from
len - The number of bytes to write

append

public PrintStream append(char c)
Description copied from interface: Appendable
Appends the Unicode character, c, to this Appendable object.

Specified by:
append in interface Appendable
Parameters:
c - the character to append.
Returns:
a reference to this object.
Since:
1.5

append

public PrintStream append(CharSequence cs)
Description copied from interface: Appendable
Appends the specified sequence of Unicode characters to this Appendable object. The entire sequence may not be appended, if constrained by the underlying implementation. For example, a buffer may reach its size limit before the entire sequence is appended.

Specified by:
append in interface Appendable
Parameters:
cs - the character sequence to append. If seq is null, then the string "null" (the string representation of null) is appended.
Returns:
a reference to this object.
Since:
1.5

append

public PrintStream append(CharSequence cs,
                          int start,
                          int end)
Description copied from interface: Appendable
Appends the specified subsequence of Unicode characters to this Appendable object, starting and ending at the specified positions within the sequence. The entire sequence may not be appended, if constrained by the underlying implementation. For example, a buffer may reach its size limit before the entire sequence is appended. The behaviour of this method matches the behaviour of append(seq.subSequence(start,end)) when the sequence is not null.

Specified by:
append in interface Appendable
Parameters:
cs - the character sequence to append. If seq is null, then the string "null" (the string representation of null) is appended.
start - the index of the first Unicode character to use from the sequence.
end - the index of the last Unicode character to use from the sequence.
Returns:
a reference to this object.
Since:
1.5

printf

public PrintStream printf(String format,
                          Object... args)
Since:
1.5

printf

public PrintStream printf(Locale locale,
                          String format,
                          Object... args)
Since:
1.5

format

public PrintStream format(String format,
                          Object... args)
Since:
1.5

format

public PrintStream format(Locale locale,
                          String format,
                          Object... args)
Since:
1.5