Response Code

You can set the status code with

public void HttpServletResponse.setStatus(int sc);

Mnemonic	Code	Meaning
SC_OK	200	Everything's OK.
SC_NO_CONTENT	204	There is nothing to return.
SC_MOVED_PERMANENTLY	301	The requested resource has moved. Put new URL in Location header.
SC_MOVED_TEMPORARILY	302	Temporary move. Put new URL in Location header.
SC_UNAUTHORIZED	401	Not authorized.
SC_NOT_FOUND	404	Document was not found.
SC_INTERNAL_SERVER_ERROR	500	Server is broken.