Spring - 登录后调用AuthenticationEntryPoint

Question

在我的Spring应用程序中，如果用户未登录，我想返回401状态。我创建了一个自定义的AuthenticationEntryPoint来执行此操作：

@Component( "restAuthenticationEntryPoint" )
public class RestAuthenticationEntryPoint
        implements AuthenticationEntryPoint {

    @Override
    public void commence(
            HttpServletRequest request,
            HttpServletResponse response,
            AuthenticationException authException) throws IOException {

        response.sendError( HttpServletResponse.SC_UNAUTHORIZED, "Unauthorized" );
    }
}

配置：

http.exceptionHandling().authenticationEntryPoint(restAuthenticationEntryPoint)
                .and()
                .authorizeRequests()
                .anyRequest().authenticated();

问题是即使在成功验证后，也会始终调用commence()。这是为什么？