SpringBoot拦截器与过滤器

拦截器

• 自定义拦截器

  @Component
  public class LoginInterceptor implements HandlerInterceptor {
     
      @Autowired
      private LoginService loginService;
  
      @Override
      public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
          
          String token = request.getHeader("Authorization");
          
          SysUser sysUser = loginService.checkToken(token);
          if (sysUser == null){
              Result result = Result.fail(ErrorCode.NO_LOGIN.getCode(), "未登录");
              
              response.setContentType("application/json;charset=utf-8");
              response.getWriter().print(JSON.toJSONString(result));
              return false;
          }
          
          return true;
      }
  }
  

• 注册拦截器，实现implements WebMvcConfigurer

  @Configuration
  public class WebMVCConfig implements WebMvcConfigurer {
  
      @Autowired
      private LoginInterceptor loginInterceptor;
  
      @Override
      public void addInterceptors(InterceptorRegistry registry) {
          registry.addInterceptor(loginInterceptor)
                  .addPathPatterns("/test");
      }
  }
  

过滤器

• 自定义filter

  @WebFilter(filterName = "testFilter", urlPatterns = "/*")
  public class TestFilter implements Filter {
  
      @Override
      public void init(FilterConfig filterConfig){
      }
  
      @Override
      public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
          System.out.println("我是过滤器的执行方法，客户端向Servlet发送的请求被我拦截到了");
  
          filterChain.doFilter(servletRequest, servletResponse);
          
          System.out.println("我是过滤器的执行方法，Servlet向客户端发送的响应被我拦截到了");
      }
  
      // 在销毁Filter时自动调用
      @Override
      public void destroy() {
          System.out.println("我是过滤器的被销毁时调用的方法！" );
      }
  }
  

• 主启动类加@ServletComponentScan 注解

  @SpringBootApplication
  @ServletComponentScan
  public class SpringBootApplication {
  
      public static void main(String[] args) {
          SpringApplication.run(SpringBootApplication.class, args);
      }
  
  }