java.io

Class Writer

Implemented Interfaces:
Appendable, AutoCloseable, Closeable, Flushable
Known Direct Subclasses:
BufferedWriter, CharArrayWriter, FilterWriter, OutputStreamWriter, PipedWriter, PrintWriter, StringWriter

public abstract class Writer
extends Object
implements Appendable, Closeable, Flushable

This abstract class forms the base of the hierarchy of classes that write output as a stream of chars. It provides a common set of methods for writing chars to stream. Subclasses implement and/or extend these methods to write chars in a particular manner or to a particular destination such as a file on disk or network connection.

Field Summary

protected Object
lock
This is the object used to synchronize criticial code sections for thread safety.

Constructor Summary

Writer()
This is the default no-argument constructor for this class.
Writer(Object lock)
This method initializes a Writer that will synchronize on the specified Object.

Method Summary

Writer
append(char c)
Writer
append(CharSequence cs)
Writer
append(CharSequence cs, int start, int end)
abstract void
close()
This method closes the stream.
abstract void
flush()
This method forces any data that may have been buffered to be written to the underlying output device.
void
write(char[] buf)
This method all the writes char from the passed array to the output stream.
abstract void
write(char[] buf, int offset, int len)
This method writes len char from the specified array buf starting at index offset into the array.
void
write(int b)
This method writes a single char to the output stream.
void
write(String str)
This method writes all the characters in a String to the output.
void
write(String str, int offset, int len)
This method writes len chars from the String starting at position offset.

Methods inherited from class java.lang.Object

clone, equals, extends Object> getClass, finalize, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

lock

protected Object lock
This is the object used to synchronize criticial code sections for thread safety. Subclasses should use this field instead of using synchronized methods or explicity synchronizations on this

Constructor Details

Writer

protected Writer()
This is the default no-argument constructor for this class. This method will set up the class to synchronize criticial sections on itself.

Writer

protected Writer(Object lock)
This method initializes a Writer that will synchronize on the specified Object.
Parameters:
lock - The Object to use for synchronizing critical sections. Must not be null.

Method Details

append

public Writer append(char c)
            throws IOException
Specified by:
append in interface Appendable
Since:
1.5

append

public Writer append(CharSequence cs)
            throws IOException
Specified by:
append in interface Appendable
Since:
1.5

append

public Writer append(CharSequence cs,
                     int start,
                     int end)
            throws IOException
Specified by:
append in interface Appendable
Since:
1.5

close

public abstract void close()
            throws IOException
This method closes the stream. Any internal or native resources associated with this stream are freed. Any subsequent attempt to access the stream might throw an exception.

This method in this class does nothing.

Specified by:
close in interface Closeable
close in interface AutoCloseable
Throws:
IOException - If an error occurs

flush

public abstract void flush()
            throws IOException
This method forces any data that may have been buffered to be written to the underlying output device. Please note that the host environment might perform its own buffering unbeknowst to Java. In that case, a write made (for example, to a disk drive) might be cached in OS buffers instead of actually being written to disk.
Specified by:
flush in interface Flushable
Throws:
IOException - If an error occurs

write

public void write(char[] buf)
            throws IOException
This method all the writes char from the passed array to the output stream. This method is equivalent to write(buf, 0, buf.length) which is exactly how it is implemented in this class.
Parameters:
buf - The array of char to write
Throws:
IOException - If an error occurs

write

public abstract void write(char[] buf,
                           int offset,
                           int len)
            throws IOException
This method writes len char from the specified array buf starting at index offset into the array.

Subclasses must provide an implementation of this abstract method.

Parameters:
buf - The array of char to write from
offset - The index into the array to start writing from
len - The number of char to write
Throws:
IOException - If an error occurs

write

public void write(int b)
            throws IOException
This method writes a single char to the output stream.
Parameters:
b - The char to be written to the output stream, passed as an int
Throws:
IOException - If an error occurs

write

public void write(String str)
            throws IOException
This method writes all the characters in a String to the output.
Parameters:
str - The String whose chars are to be written.
Throws:
IOException - If an error occurs

write

public void write(String str,
                  int offset,
                  int len)
            throws IOException
This method writes len chars from the String starting at position offset.
Parameters:
str - The String that is to be written
offset - The character offset into the String to start writing from
len - The number of chars to write
Throws:
IOException - If an error occurs

Writer.java -- Base class for character output streams Copyright (C) 1998, 1999, 2001, 2003, 2004, 2005 Free Software Foundation, Inc. This file is part of GNU Classpath. GNU Classpath is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GNU Classpath is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNU Classpath; see the file COPYING. If not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. Linking this library statically or dynamically with other modules is making a combined work based on this library. Thus, the terms and conditions of the GNU General Public License cover the whole combination. As a special exception, the copyright holders of this library give you permission to link this library with independent modules to produce an executable, regardless of the license terms of these independent modules, and to copy and distribute the resulting executable under terms of your choice, provided that you also meet, for each linked independent module, the terms and conditions of the license of that module. An independent module is a module which is not derived from or based on this library. If you modify this library, you may extend this exception to your version of the library, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version.