java.io
Class PrintWriter
java.lang.Object
|
+--java.io.Writer
|
+--java.io.PrintWriter
public class
PrintWriterextends
Writer This class prints Java primitive values and objects 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 whenever one of the println
methods is
called. (Note that this differs from the PrintStream
class which also auto-flushes when it encounters a newline character
in the chars written).
Authors:- Per Bothner <bothner@cygnus.com>
- Aaron M. Renn (arenn@urbanophile.com)
out
protected Writer out
This is the underlying Writer
we are sending output
to
PrintWriter
public PrintWriter(java.io.OutputStream out)
This method initializes a new PrintWriter
object to write
to the specified OutputStream
. Characters will be converted
to chars using the system default encoding. Auto-flush functionality
will not be enabled.
Parameters:
PrintWriter
public PrintWriter(java.io.OutputStream out, boolean autoflush)
This method initializes a new PrintWriter
object to write
to the specified OutputStream
. Characters will be converted
to chars using the system default encoding. This form of the
constructor allows auto-flush functionality to be enabled if desired
Parameters:
PrintWriter
public PrintWriter(java.io.Writer wr)
This method intializes a new PrintWriter
object to write
to the specified output sink. The form of the constructor does not
enable auto-flush functionality.
Parameters:
PrintWriter
public PrintWriter(java.io.Writer wr, boolean autoflush)
This method intializes a new PrintWriter
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 line is terminated or newline character is written.
Parameters:
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
close
public void close()
This method closes this stream and all underlying streams.
flush
public void flush()
This method flushes any buffered chars to the underlying stream and
then flushes that stream as well.
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:
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:
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:
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:
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:
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:
print
public void print(java.lang.Object obj)
This method prints an Object
to the stream. The actual
value printed is determined by calling the String.valueOf()
method.
Parameters:
print
public void print(java.lang.String str)
This method prints a String
to the stream. The actual
value printed depends on the system default encoding.
Parameters:
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:
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:
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:
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:
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:
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:
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:
println
public void println(java.lang.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:
println
public void println(java.lang.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:
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:
setError
protected void setError()
This method can be called by subclasses to indicate that an error
has occurred and should be reported by checkError
.
write
public void write(char[] charArray)
This method write all the chars in the specified array to the output.
Parameters:
write
public void write(char[] charArray, int offset, int count)
This method writes count
chars from the specified array
starting at index offset
into the array.
Parameters:
write
public void write(int ch)
This method writes a single char to the stream.
Parameters:
write
public void write(java.lang.String str)
This method writes the contents of the specified String
to the underlying stream.
Parameters:
write
public void write(java.lang.String str, int offset, int count)
This method writes count
chars from the specified
String
to the output starting at character position
offset
into the String
Parameters:
checkError()
method. Additionally, this stream can be designated as "autoflush" when created so that any writes are automatically flushed to the underlying output sink whenever one of theprintln
methods is called. (Note that this differs from thePrintStream
class which also auto-flushes when it encounters a newline character in the chars written).