Class java.io.Writer - JDK 5 Documentation v1.1.8, Java 2 SDK 英文文档

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Class java.io.Writer

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

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, BufferedWriter, CharArrayWriter, FilterWriter, OutputStreamWriter, FileWriter, PipedWriter, PrintWriter, StringWriter, Reader

lock: The object used to synchronize operations on this stream.

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

close(): Close the stream, flushing it first.
flush(): Flush the stream.
write(char[]): Write an array of characters.
write(char[], int, int): Write a portion of an array of characters.
write(int): Write a single character.
write(String): Write a string.
write(String, int, int): Write a portion of a string.

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.

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.

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.

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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