code: public void close() throws java.io.IOException
      {
          if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled()){  
              Tr.debug(tc, "close output");         
          }
  
          if(this._listener!= null && this.isOutputStreamNBClosed()){
              if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled()){  
                  Tr.debug(tc, "output stream close previously completed ...return ");
              }
              return;
          }
  
          try{
              this._httpOut.setAsyncServletWriteListenerCallBack(null);    
              super.close();
          }
          finally {
              if(this._listener!= null)
                  this.setOutputStreamNBClosed(true);
          }
      }
docs: /* (non-Javadoc)
  @see com.ibm.ws.webcontainer.osgi.response.WCOutputStream#close()