Class: java.io.Writer
- public abstract class Writer
- implements Appendable, Closeable, Flushable
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.
Methods
-
Writertop
protected Writer()Creates a new character-stream writer whose critical sections will synchronize on the writer itself. -
Writertop
protected Writer(Object lock)Creates a new character-stream writer whose critical sections will synchronize on the given object. -
appendtop
public Writer append(char c) throws IOExceptionAppends the specified character to this writer.An invocation of this method of the form out.append(c) behaves in exactly the same way as the invocation
out.write(c)- Specified by:
- append from Appendable
-
appendtop
Appends the specified character sequence to this writer.An invocation of this method of the form out.append(csq) behaves in exactly the same way as the invocation
out.write(csq.toString())Depending on the specification of toString for the character sequence csq, the entire sequence may not be appended. For instance, invoking the toString method of a character buffer will return a subsequence whose content depends upon the buffer's position and limit.
- Specified by:
- append from Appendable
-
appendtop
Appends a subsequence of the specified character sequence to this writer. Appendable.An invocation of this method of the form out.append(csq, start, end) when csq is not null behaves in exactly the same way as the invocation
out.write(csq.subSequence(start, end).toString())- Specified by:
- append from Appendable
-
closetop
public abstract void close() throws IOExceptionCloses the stream, flushing it first. Once the stream has been closed, further write() or flush() invocations will cause an IOException to be thrown. Closing a previously closed stream has no effect. -
flushtop
public abstract void flush() throws IOExceptionFlushes 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.If the intended destination of this stream is an abstraction provided by the underlying operating system, for example a file, then flushing the stream guarantees only that bytes previously written to the stream are passed to the operating system for writing; it does not guarantee that they are actually written to a physical device such as a disk drive.
-
writetop
public void write(int c) throws IOExceptionWrites 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.
-
writetop
public void write(String str) throws IOExceptionWrites a string. -
writetop
public void write(String str, int off, int len) throws IOExceptionWrites a portion of a string. -
writetop
public void write(char[] cbuf) throws IOExceptionWrites an array of characters. -
writetop
public abstract void write(char[] cbuf, int off, int len) throws IOExceptionWrites a portion of an array of characters.
Fields
-
lock
protected Object lockThe 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.