Client and backend. This class is shared: the same code is compiled into your app and into your server, so everything on this page works in both.

public abstract class Writer

  1. Object
  2. Writer

ImplementsAppendable, AutoCloseable, Closeable, Flushable

Known subtypesBufferedWriter, OutputStreamWriter, PrintWriter, StringWriter

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. Since: JDK1.1, CLDC 1.0 See Also:OutputStreamWriter, Reader

Fields

protected Object lockThe object used to synchronize operations on this stream.

Constructors

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.

Methods

public Writer append(CharSequence csq) throws IOExceptionWrites csq, or “null” when it is null.
public Writer append(char c) throws IOExceptionWrites c.
public Writer append(CharSequence csq, int start, int end) throws IOExceptionWrites the characters of csq from start up to end.
public abstract void close() throws IOExceptionClose the stream, flushing it first.
public abstract void flush() throws IOExceptionFlush the stream.
public void write(char[] cbuf) throws IOExceptionWrite an array of characters.
public abstract void write(char[] cbuf, int off, int len) throws IOExceptionWrite a portion of an array of characters.
public void write(int c) throws IOExceptionWrite a single character.
public void write(String str) throws IOExceptionWrite a string.
public void write(String str, int off, int len) throws IOExceptionWrite a portion of a string.

Inherited methods

From Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait, clone, finalize

Field details

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 details

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. lock - Object to synchronize on.

Method details

append

public Writer append(CharSequence csq) throws IOException
Writes csq, or “null” when it is null.

Parameters

csq CharSequence
the character sequence to append.

Returns

this Appendable.

Throws

IOException
if an I/O error occurs.

append

public Writer append(char c) throws IOException
Writes c.

Parameters

c char
the character to append.

Returns

this Appendable.

Throws

IOException
if an I/O error occurs.

append

public Writer append(CharSequence csq, int start, int end) throws IOException
Writes the characters of csq from start up to end.

Parameters

csq CharSequence
the character sequence to append.
start int
the first index of the subsequence of csq that is appended.
end int
the last index of the subsequence of csq that is appended.

Returns

this Appendable.

Throws

IndexOutOfBoundsException
if start end or end is greater than the length of csq.
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

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 there are any issues writing the data.

write

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

Throws

IOException

write

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

Throws

IOException

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

write

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

Throws

IOException

write

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

Throws

IOException