SpringBoot2零基础到精通之异常处理与web原生组件注入

@Slf4j
@ControllerAdvice
public class GlobalExceptionHandler {

    @ExceptionHandler({ArithmeticException.class, NullPointerException.class})
    public String handleArithException(Exception e) {
        log.info("系统捕获到异常信息：{}", e);
        return "login";
    }
}

@ResponseStatus(value = HttpStatus.FORBIDDEN, reason = "用户数量太多")
public class UserTooManyException extends RuntimeException{

    public UserTooManyException() {

    }
    public UserTooManyException(String message) {
        super(message);
    }
}

// 判断用户数量抛出用户数量过多的自定义异常
if (users.size() > 3) {
    throw new UserTooManyException();
}

// 声明拦截的请求
@WebServlet(urlPatterns = "/my")
public class MyServlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.getWriter().write("385695");
    }
}

@Slf4j
@WebFilter(urlPatterns = {"/css/*", "/images/*"})
public class MyFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        log.info("MyFilter初始化……");
    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        log.info("MyFilter方法开始工作了……");
        filterChain.doFilter(servletRequest, servletResponse);
    }

    @Override
    public void destroy() {
        log.info("MyFilter销毁了……");
    }
}

@Slf4j
@WebListener
public class MyServletContextListener implements ServletContextListener {
    @Override
    public void contextInitialized(ServletContextEvent sce) {
        log.info("MyServletContextListener监听到项目初始化完成……");
    }

    @Override
    public void contextDestroyed(ServletContextEvent sce) {
        log.info("MyServletContextListener监听到项目已经销毁……");
    }
}

@Configuration
public class MyRegistConfig {

    @Bean
    public ServletRegistrationBean MyServlet() {
        MyServlet myServlet = new MyServlet();
        return new ServletRegistrationBean(myServlet, "/my", "/my02");
    }


    @Bean
    public FilterRegistrationBean myFilter() {
        MyFilter myFilter = new MyFilter();
        FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean(myFilter);
        filterRegistrationBean.setUrlPatterns(Arrays.asList("/my", "/my02"));
        return filterRegistrationBean;
    }

    @Bean
    public ServletListenerRegistrationBean myListener() {
        MyServletContextListener listener = new MyServletContextListener();
        return new ServletListenerRegistrationBean(listener);
    }
}