StaticUserWebFilter.java 文件源码

@Override
public void doFilter(ServletRequest request, ServletResponse response,
                     FilterChain chain
                     ) throws IOException, ServletException {
  HttpServletRequest httpRequest = (HttpServletRequest) request;
  // if the user is already authenticated, don't override it
  if (httpRequest.getRemoteUser() != null) {
    chain.doFilter(request, response);
  } else {
    HttpServletRequestWrapper wrapper = 
        new HttpServletRequestWrapper(httpRequest) {
      @Override
      public Principal getUserPrincipal() {
        return user;
      }
      @Override
      public String getRemoteUser() {
        return username;
      }
    };
    chain.doFilter(wrapper, response);
  }
}