This class is a character output stream that uses an internal StringBuffer object as the destination of the characters written to the stream. When you create a StringWriter, you may optionally specify an initial size for the StringBuffer, but you do not specify the StringBuffer itself; it is managed internally by the StringWriter and grows as necessary to accommodate the characters written to it. StringWriter defines the standard write( ) , flush( ), and close( ) methods all Writer subclasses define, as well as two methods to obtain the characters that have been written to the stream's internal buffer. toString( ) returns the contents of the internal buffer as a String, and getBuffer( ) returns the buffer itself. Note that getBuffer( ) returns a reference to the actual internal buffer, not a copy of it, so any changes you make to the buffer are reflected in subsequent calls to toString( ). StringWriter is quite similar to CharArrayWriter, but does not have a byte-stream analog.

Figure 9-60. java.io.StringWriter

public class StringWriter extends Writer {
// Public Constructors
     public StringWriter( );  
     public StringWriter(int initialSize);  
// Public Instance Methods
5.0  public StringWriter append(CharSequence csq);  
5.0  public StringWriter append(char c);  
5.0  public StringWriter append(CharSequence csq, int start, int end);  
     public StringBuffer getBuffer( );  
// Public Methods Overriding Writer
     public void close( ) throws IOException;                             empty
     public void flush( );                                                empty
     public void write(int c);  
     public void write(String str);  
     public void write(String str, int off, int len);  
     public void write(char[ ] cbuf, int off, int len);  
// Public Methods Overriding Object
     public String toString( );  
}