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java.io

Class PrintWriter

java.lang.Object
|
+--java.io.Writer
   |
   +--java.io.PrintWriter


public class PrintWriter

extends 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:

Field Summary

java.io.Writerout

This is the underlying Writer we are sending output to

Constructor Summary

PrintWriter(java.io.Writer wr)

This method intializes a new PrintWriter object to write to the specified output sink.
PrintWriter(java.io.Writer wr, boolean autoflush)

This method intializes a new PrintWriter object to write to the specified output sink.
PrintWriter(java.io.OutputStream out)

This method initializes a new PrintWriter object to write to the specified OutputStream.
PrintWriter(java.io.OutputStream out, boolean autoflush)

This method initializes a new PrintWriter object to write to the specified OutputStream.

Method Summary

booleancheckError()

This method checks to see if an error has occurred on this stream.
voidclose()

This method closes this stream and all underlying streams.
voidflush()

This method flushes any buffered chars to the underlying stream and then flushes that stream as well.
voidprint(java.lang.String str)

This method prints a String to the stream.
voidprint(char ch)

This method prints a char to the stream.
voidprint(char[] charArray)

This method prints an array of characters to the stream.
voidprint(boolean bool)

This methods prints a boolean value to the stream.
voidprint(int inum)

This method prints an integer to the stream.
voidprint(long lnum)

This method prints a long to the stream.
voidprint(float fnum)

This method prints a float to the stream.
voidprint(double dnum)

This method prints a double to the stream.
voidprint(java.lang.Object obj)

This method prints an Object to the stream.
voidprintln()

This method prints a line separator sequence to the stream.
voidprintln(boolean bool)

This methods prints a boolean value to the stream.
voidprintln(int inum)

This method prints an integer to the stream.
voidprintln(long lnum)

This method prints a long to the stream.
voidprintln(float fnum)

This method prints a float to the stream.
voidprintln(double dnum)

This method prints a double to the stream.
voidprintln(java.lang.Object obj)

This method prints an Object to the stream.
voidprintln(java.lang.String str)

This method prints a String to the stream.
voidprintln(char ch)

This method prints a char to the stream.
voidprintln(char[] charArray)

This method prints an array of characters to the stream.
voidsetError()

This method can be called by subclasses to indicate that an error has occurred and should be reported by checkError.
voidwrite(int ch)

This method writes a single char to the stream.
voidwrite(char[] charArray, int offset, int count)

This method writes count chars from the specified array starting at index offset into the array.
voidwrite(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
voidwrite(char[] charArray)

This method write all the chars in the specified array to the output.
voidwrite(java.lang.String str)

This method writes the contents of the specified String to the underlying stream.

Field Details

out

protected Writer out

This is the underlying Writer we are sending output to


Constructor Details

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:


Method Details

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:


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: