java.io
Class Writer

java.lang.Object
  extended by java.io.Writer
Direct Known Subclasses:
OutputStreamWriter

public abstract class Writer
extends Object

Abstract class for writing to character streams. The only methods that a subclass must implement are write(char[], int, int), flush(), and close(). Most subclasses, however, will override some of the methods defined here in order to provide higher efficiency, additional functionality, or both.

See Also:
Writer, OutputStreamWriter, Reader
Since:
JDK1.1

Field Summary
protected  Object lock
          The object used to synchronize operations on this stream.
 
Constructor Summary
protected Writer()
          Create a new character-stream writer whose critical sections will synchronize on the writer itself.
protected Writer(Object lock)
          Create a new character-stream writer whose critical sections will synchronize on the given object.
 
Method Summary
abstract  void close()
          Close the stream, flushing it first.
abstract  void flush()
          Flush the stream.
 void write(char[] cbuf)
          Write an array of characters.
abstract  void write(char[] cbuf, int off, int len)
          Write a portion of an array of characters.
 void write(int c)
          Write a single character.
 void write(String str)
          Write a string.
 void write(String str, int off, int len)
          Write a portion of a string.
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 



Field Detail

lock

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.



Constructor Detail

Writer

protected Writer()
Create a new character-stream writer whose critical sections will synchronize on the writer itself.


Writer

protected Writer(Object lock)
Create a new character-stream writer whose critical sections will synchronize on the given object.

Parameters:
lock - Object to synchronize on.


Method Detail

write

public void write(int c)
           throws IOException
Write a single character. The character to be written is contained in the 16 low-order bits of the given integer value; the 16 high-order bits are ignored.

Subclasses that intend to support efficient single-character output should override this method.

Parameters:
c - int specifying a character to be written.
Throws:
IOException - If an I/O error occurs

write

public void write(char[] cbuf)
           throws IOException
Write an array of characters.

Parameters:
cbuf - Array of characters to be written
Throws:
IOException - If an I/O error occurs

write

public abstract void write(char[] cbuf,
                           int off,
                           int len)
                    throws IOException
Write a portion of an array of characters.

Parameters:
cbuf - Array of characters
off - Offset from which to start writing characters
len - Number of characters to write
Throws:
IOException - If an I/O error occurs

write

public void write(String str)
           throws IOException
Write a string.

Parameters:
str - String to be written
Throws:
IOException - If an I/O error occurs

write

public void write(String str,
                  int off,
                  int len)
           throws IOException
Write a portion of a string.

Parameters:
str - A String
off - Offset from which to start writing characters
len - Number of characters to write
Throws:
IOException - If an I/O error occurs

flush

public abstract void flush()
                    throws IOException
Flush the stream. If the stream has saved any characters from the various write() methods in a buffer, write them immediately to their intended destination. Then, if that destination is another character or byte stream, flush it. Thus one flush() invocation will flush all the buffers in a chain of Writers and OutputStreams.

Throws:
IOException - If an I/O error occurs

close

public abstract void close()
                    throws IOException
Close the stream, flushing it first. Once a stream has been closed, further write() or flush() invocations will cause an IOException to be thrown. Closing a previously-closed stream, however, has no effect.

Throws:
IOException - If an I/O error occurs





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