从tomcat的Filter类方法响应servlet客户端时如何设置http状态代码

从tomcat的Filter类方法响应servlet客户端时如何设置http状态代码

我不久就实现了用于身份验证的过滤器。我已经编写了类似于以下内容的代码：

public void doFilter(ServletRequest req, ServletResponse resp,   FilterChain chain){    HttpServletResponse response=(HttpServletResponse) resp;    boolean authenticated=false;    // perform authentication    if (authenticated)    {         chain.doFilter(req, response);    }    else    {         // don't continue the chain         response.setStatus(HttpServletResponse.SC_UNAUTHORIZED);         response.setHeader("WWW-Authenticate", "BASIC realm="Your realm"");         response.setContentType("what you need");         PrintWriter writer=response.getWriter();         // don't set content length , don't close    }}