java.io
Class PrintWriter

java.lang.Object
  java.io.Writer
      java.io.PrintWriter

public class PrintWriter

extends Writer

Print formatted representations of objects to a text-output stream. This class implements all of the print methods found in PrintStream. It does not contain methods for writing raw bytes, for which a program should use unencoded byte streams.

Unlike the PrintStream class, if automatic flushing is enabled it will be done only when one of the println() methods is invoked, rather than whenever a newline character happens to be output. The println() methods use the platform's own notion of line separator rather than the newline character.

Methods in this class never throw I/O exceptions. The client may inquire as to whether any errors have occurred by invoking checkError().

Since:

JDK1.1

Method Summary
boolean	checkError() public boolean checkError() Flush the stream if it's not closed and check its error state. Errors are cumulative; once the stream encounters an error, this routine will return true on all successive calls. Returns: True if the print stream has encountered an error, either on the underlying output stream or during a format conversion.
void	close() public void close() Close the stream. Specified by: close in class Writer See Also: checkError()
void	flush() public void flush() Flush the stream. Specified by: flush in class Writer See Also: checkError()
void	print(boolean b) public void print(boolean b) Print a boolean value. The string produced by String.valueOf(boolean) is translated into bytes according to the platform's default character encoding, and these bytes are written in exactly the manner of the write(int) method. Parameters: b - The boolean to be printed
void	print(char c) public void print(char c) Print a character. The character is translated into one or more bytes according to the platform's default character encoding, and these bytes are written in exactly the manner of the write(int) method. Parameters: c - The char to be printed
void	print(char[] s) public void print(char[] s) Print an array of characters. The characters are converted into bytes according to the platform's default character encoding, and these bytes are written in exactly the manner of the write(int) method. Parameters: s - The array of chars to be printed Throws: NullPointerException - If s is null
void	print(double d) public void print(double d) Print a double-precision floating-point number. The string produced by String.valueOf(double) is translated into bytes according to the platform's default character encoding, and these bytes are written in exactly the manner of the write(int) method. Parameters: d - The double to be printed See Also: Double.toString(double)
void	print(float f) public void print(float f) Print a floating-point number. The string produced by String.valueOf(float) is translated into bytes according to the platform's default character encoding, and these bytes are written in exactly the manner of the write(int) method. Parameters: f - The float to be printed See Also: Float.toString(float)
void	print(int i) public void print(int i) Print an integer. The string produced by String.valueOf(int) is translated into bytes according to the platform's default character encoding, and these bytes are written in exactly the manner of the write(int) method. Parameters: i - The int to be printed See Also: Integer.toString(int)
void	print(long l) public void print(long l) Print a long integer. The string produced by String.valueOf(long) is translated into bytes according to the platform's default character encoding, and these bytes are written in exactly the manner of the write(int) method. Parameters: l - The long to be printed See Also: Long.toString(long)
void	print(Object obj) public void print(Object obj) Print an object. The string produced by the String.valueOf(Object) method is translated into bytes according to the platform's default character encoding, and these bytes are written in exactly the manner of the write(int) method. Parameters: obj - The Object to be printed See Also: Object.toString()
void	print(String s) public void print(String s) Print a string. If the argument is null then the string "null" is printed. Otherwise, the string's characters are converted into bytes according to the platform's default character encoding, and these bytes are written in exactly the manner of the write(int) method. Parameters: s - The String to be printed
void	println() public void println() Terminate the current line by writing the line separator string. The line separator string is defined by the system property line.separator, and is not necessarily a single newline character ('\n').
void	println(boolean x) public void println(boolean x) Print a boolean value and then terminate the line. This method behaves as though it invokes print(boolean) and then println(). Parameters: x - the boolean value to be printed
void	println(char x) public void println(char x) Print a character and then terminate the line. This method behaves as though it invokes print(char) and then println(). Parameters: x - the char value to be printed
void	println(char[] x) public void println(char[] x) Print an array of characters and then terminate the line. This method behaves as though it invokes print(char[]) and then println(). Parameters: x - the array of char values to be printed
void	println(double x) public void println(double x) Print a double-precision floating-point number and then terminate the line. This method behaves as though it invokes print(double) and then println(). Parameters: x - the double value to be printed
void	println(float x) public void println(float x) Print a floating-point number and then terminate the line. This method behaves as though it invokes print(float) and then println(). Parameters: x - the float value to be printed
void	println(int x) public void println(int x) Print an integer and then terminate the line. This method behaves as though it invokes print(int) and then println(). Parameters: x - the int value to be printed
void	println(long x) public void println(long x) Print a long integer and then terminate the line. This method behaves as though it invokes print(long) and then println(). Parameters: x - the long value to be printed
void	println(Object x) public void println(Object x) Print an Object and then terminate the line. This method behaves as though it invokes print(Object) and then println(). Parameters: x - the Object value to be printed
void	println(String x) public void println(String x) Print a String and then terminate the line. This method behaves as though it invokes print(String) and then println(). Parameters: x - the String value to be printed
protected  void	setError() protected void setError() Indicate that an error has occurred.
void	write(char[] buf) public void write(char[] buf) Write an array of characters. This method cannot be inherited from the Writer class because it must suppress I/O exceptions. Overrides: write in class Writer Parameters: buf - Array of characters to be written
void	write(char[] buf, int off, int len) public void write(char[] buf, int off, int len) Write a portion of an array of characters. Specified by: write in class Writer Parameters: buf - Array of characters off - Offset from which to start writing characters len - Number of characters to write
void	write(int c) public void write(int c) Write a single character. Overrides: write in class Writer Parameters: c - int specifying a character to be written.
void	write(String s) public void write(String s) Write a string. This method cannot be inherited from the Writer class because it must suppress I/O exceptions. Overrides: write in class Writer Parameters: s - String to be written
void	write(String s, int off, int len) public void write(String s, int off, int len) Write a portion of a string. Overrides: write in class Writer Parameters: s - A String off - Offset from which to start writing characters len - Number of characters to write

 

Constructor Summary

PrintWriter(OutputStream out) public PrintWriter(OutputStream out) Create a new PrintWriter, without automatic line flushing, from an existing OutputStream. This convenience constructor creates the necessary intermediate OutputStreamWriter, which will convert characters into bytes using the default character encoding. Parameters: out - An output stream See Also: OutputStreamWriter.OutputStreamWriter(java.io.OutputStream)

PrintWriter(OutputStream out, boolean autoFlush) public PrintWriter(OutputStream out, boolean autoFlush) Create a new PrintWriter from an existing OutputStream. This convenience constructor creates the necessary intermediate OutputStreamWriter, which will convert characters into bytes using the default character encoding. Parameters: out - An output stream autoFlush - A boolean; if true, the println() methods will flush the output buffer See Also: OutputStreamWriter.OutputStreamWriter(java.io.OutputStream)

PrintWriter(Writer out) public PrintWriter(Writer out) Create a new PrintWriter, without automatic line flushing. Parameters: out - A character-output stream

PrintWriter(Writer out, boolean autoFlush) public PrintWriter(Writer out, boolean autoFlush) Create a new PrintWriter. Parameters: out - A character-output stream autoFlush - A boolean; if true, the println() methods will flush the output buffer

 

Field Summary
protected  Object	lock The object used to synchronize operations on this stream. For efficiency, a character-stream object may use an object other than itself to protect critical sections. A subclass should therefore use the object in this field rather than this or a synchronized method.
protected  Writer	out The underlying character-output stream of this PrintWriter. Since: 1.2