springboot使用过滤器和拦截器

1.Filter过滤器

@Component
public class AuthFilter implements Filter {
    private static final Log log = LogFactory.getLog(AuthFilter.class);
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        log.info("AuthFilter init OK...");
    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        log.info("AuthFilter dofilter loading...");
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;
        request.setCharacterEncoding("UTF-8");
        //1.获取用户登录信息,没有登录 去登录页面request.getRequestDispatcher("/login").forward(request, response);
        //2.获取用户访问资源，如果是登录和springlogo的请求,则放行
        String requestURI = request.getRequestURI();
        if(requestURI.equals("/login")||requestURI.equals("/favicon.ico")){
            log.info("this is a login request or spring.logo,not filter");
            setCrosHeader(response);
            filterChain.doFilter(request, response);
            return;
        }
        log.info("user request uri is "+requestURI);

        //3.获取该uri所需的权限,如果该url不需要权限，则过滤结束
        String auth = null;
        if(StringUtils.isEmpty(auth)){
            log.info("url auth is null");
            setCrosHeader(response);
            filterChain.doFilter(request, response);
            return;
        }
        //4.判断该用户是否拥有权限,如果没有
        //request.setAttribute("message", "对不起，您没有权限，请联系管理员！！！");
        //request.getRequestDispatcher("/message").forward(request, response);
        //return;
        //或使用:
        //returnNone(response,"000000", "没有访问权限或请求失败");
        //5.如果有权限，则放行
        //filterChain.doFilter(request, response);
    }
    @Override
    public void destroy() {
        log.info("AuthFilter destory Ok...");
    }

    //设置响应头放行的
    private void setCrosHeader(HttpServletResponse response){
        response.setHeader("Access-Control-Allow-Credentials", "true");
        response.setHeader("Access-Control-Allow-Origin", "*");
        response.setHeader("Access-Control-Allow-Methods",
                "POST, GET, OPTIONS, DELETE");
        response.setHeader("Access-Control-Max-Age", "3600");
        response.setHeader("Access-Control-Allow-Headers", "x-requested-with");
        response.setCharacterEncoding("utf-8");
    }
    //设置过滤后的响应头
    private void returnNone(HttpServletResponse response, String code,
                            String msg) throws IOException {

        setCrosHeader(response);
        response.setContentType("application/json");
        response.setCharacterEncoding("UTF-8");
        response.setHeader("Cache-Control", "no-cache");
        PrintWriter writer = response.getWriter();
        writer.write(JSONObject.toJSONString(ResultPageInfoJsonUtils.getFailedJson(code,msg)));
        writer.flush();
        writer.close();
        return;
    }
}

写一个config类：

@Configuration
public class FilterConfig {
    @Bean
    public FilterRegistrationBean filterRegistrationBean(AuthFilter authFilter){
        FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean();
        filterRegistrationBean.setFilter(authFilter);
        List<String> auths = Lists.newArrayList();
        auths.add("/*");//过滤的路径
        filterRegistrationBean.setUrlPatterns(auths);

　　　　 filterRegistrationBean.setOrder(1);//如果有多个filter，可以设置filter的执行顺序

        return filterRegistrationBean;
    }
}
2.HandlerInterceptor(implements) 和 HandlerInterceptorAdapter(extends)拦截器

拦截器逻辑 
public class AuthInterceptor extends HandlerInterceptorAdapter {
    private static final Log log = LogFactory.getLog(AuthInterceptor.class);
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        if (request.getParameterMap().containsKey("hello")) {
            return true;
        }
        return false;
    }
}

创建拦截器的配置

@Component
public class InterceptorConfig extends WebMvcConfigurerAdapter {
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        // 多个拦截器组成一个拦截器链
        // addPathPatterns 用于添加拦截规则
        // excludePathPatterns 用户排除拦截
        InterceptorRegistration interceptorRegistration = registry.addInterceptor(new AuthInterceptor());
        interceptorRegistration.addPathPatterns("/*");
        interceptorRegistration.excludePathPatterns("/livestock");
        super.addInterceptors(registry);
    }
}

Filter和Interceptor的执行顺序

过滤前-拦截前-action执行-拦截后-过滤后