question: public int write ( OutputStreamWithBuffer os , char [ ] buf , int offset , int length ) throws IOException { if ( _writer == null ) { if ( _charset != null ) _writer = new OutputStreamWriter ( os , _charset ) ; else _writer = new OutputStreamWriter ( os , _encoding ) ; } _writer . write ( buf , offset , length ) ; _writer . flush ( ) ; return length ; }
target:  Writes a char buffer.