java.io

Class Writer

java.lang.Object

java.io.Writer

All Implemented Interfaces:

Closeable, Flushable, Appendable

Direct Known Subclasses:

BufferedWriter, CharArrayWriter, tijos.kernel.charset.CharsetOutputStreamWriter, FilterWriter, 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.

Author:

Aaron M. Renn (arenn@urbanophile.com), Per Bothner (bothner@cygnus.com)

Method Summary

Modifier and Type	Method and Description
Writer	append(char c) Appends the Unicode character, c, to this Appendable object.
Writer	append(CharSequence cs) Appends the specified sequence of Unicode characters to this Appendable object.
Writer	append(CharSequence cs, int start, int end) Appends the specified subsequence of Unicode characters to this Appendable object, starting and ending at the specified positions within the sequence.
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

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

Method Detail

append

public Writer append(char c)
              throws IOException

Description copied from interface: Appendable

Appends the Unicode character, c, to this Appendable object.

Specified by:

append in interface Appendable

Parameters:

c - the character to append.

Returns:

a reference to this object.

Throws:

IOException - if an I/O error occurs.

Since:

1.5

append

public Writer append(CharSequence cs)
              throws IOException

Description copied from interface: Appendable

Appends the specified sequence of Unicode characters to this Appendable object. The entire sequence may not be appended, if constrained by the underlying implementation. For example, a buffer may reach its size limit before the entire sequence is appended.

Specified by:

append in interface Appendable

Parameters:

cs - the character sequence to append. If seq is null, then the string "null" (the string representation of null) is appended.

Returns:

a reference to this object.

Throws:

IOException - if an I/O error occurs.

Since:

1.5

append

public Writer append(CharSequence cs,
                     int start,
                     int end)
              throws IOException

Description copied from interface: Appendable

Appends the specified subsequence of Unicode characters to this Appendable object, starting and ending at the specified positions within the sequence. The entire sequence may not be appended, if constrained by the underlying implementation. For example, a buffer may reach its size limit before the entire sequence is appended. The behaviour of this method matches the behaviour of append(seq.subSequence(start,end)) when the sequence is not null.

Specified by:

append in interface Appendable

Parameters:

cs - the character sequence to append. If seq is null, then the string "null" (the string representation of null) is appended.

start - the index of the first Unicode character to use from the sequence.

end - the index of the last Unicode character to use from the sequence.

Returns:

a reference to this object.

Throws:

IOException - if an I/O error occurs.

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

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