This class is a character output stream that uses an internal character array as the destination of characters written to it. When you create a CharArrayWriter, you may optionally specify an initial size for the character array, but you do not specify the character array itself; this array is managed internally by the CharArrayWriter and grows as necessary to accommodate all the characters written to it. The toString( ) and toCharArray( ) methods return a copy of all characters written to the stream, as a string and an array of characters, respectively. CharArrayWriter defines the standard write( ) , flush( ), and close( ) methods all Writer subclasses define. It also defines a few other useful methods. size( ) returns the number of characters that have been written to the stream. reset( ) resets the stream to its initial state, with an empty character array; this is more efficient than creating a new CharArrayWriter. Finally, writeTo( ) writes the contents of the internal character array to some other specified character stream. CharArrayWriter is the character-stream analog of ByteArrayOutputStream and is quite similar to StringWriter.

Figure 9-8. java.io.CharArrayWriter

public class CharArrayWriter extends Writer {
// Public Constructors
     public CharArrayWriter( );  
     public CharArrayWriter(int initialSize);  
// Public Instance Methods
5.0  public CharArrayWriter append(CharSequence csq);  
5.0  public CharArrayWriter append(char c);  
5.0  public CharArrayWriter append(CharSequence csq, int start, int end);  
     public void reset( );  
     public int size( );  
     public char[ ] toCharArray( );  
     public void writeTo(Writer out) throws IOException;  
// Public Methods Overriding Writer
     public void close( );                                                empty
     public void flush( );                                                empty
     public void write(int c);  
     public void write(char[ ] c, int off, int len);  
     public void write(String str, int off, int len);  
// Public Methods Overriding Object
     public String toString( );  
// Protected Instance Fields
     protected char[ ] buf;  
     protected int count;  
}