基于SpringBoot
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;
}
//是登录状态，放行
return true;
}
} ```
注册拦截器，实现implements WebMvcConfigurer，重写 preHandle()
``` @Configuration public class WebMVCConfig implements WebMvcConfigurer {
@Autowired
private LoginInterceptor loginInterceptor;
@Override
public void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(loginInterceptor)
.addPathPatterns("/test");
}
} ```
过滤器编写filter
```java @WebFilter(filterName = "testFilter", urlPatterns = "/*") public class TestFilter implements Filter {
@Override
public void init(FilterConfig filterConfig){
}
// 主要的业务代码编写方法
@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！，活不下去了................" );
}
} ```
主启动类加@ServletComponentScan 注解
```java @SpringBootApplication @ServletComponentScan public class SpringBootApplication {
public static void main(String[] args) {
SpringApplication.run(SpringBootApplication.class, args);
}
} ```
两者区别过滤器先执行，拦截器后执行
