在Spring中攔截器的使用
阿新 • • 發佈:2020-09-02
Filter
Filter是Servlet容器實現的,並不是由Spring 實現的
下面是一個例子
import java.io.IOException; import javax.servlet.FilterChain; import javax.servlet.ServletException; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import lombok.extern.slf4j.Slf4j; import org.springframework.web.filter.OncePerRequestFilter; /** * @date: 2020-09-02 */ @Slf4j public class MyFilter extends OncePerRequestFilter { @Override protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException { log.info("filter - request : {}, response : {}", request, response); filterChain.doFilter(request, response); } }
HandlerInterceptorAdapter
HandlerInterceptorAdapter 是Spring 通過Aop來實現的
下面是一個例子
import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import lombok.extern.slf4j.Slf4j; import org.springframework.web.servlet.handler.HandlerInterceptorAdapter; /** * @date: 2020-09-02 */ @Slf4j public class MyInterceptor extends HandlerInterceptorAdapter { @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception { log.info("HandlerInterceptorAdapter - request : {}, response : {}", request, response); return true; } }
HandlerMethodArgumentResolver
通過它可以對controller方法裡面的引數進行賦值,比如@RequestParam註解就是通過這個攔截器實現的
下面是一個例子
import java.lang.annotation.ElementType; import java.lang.annotation.Retention; import java.lang.annotation.RetentionPolicy; import java.lang.annotation.Target; @Target({ElementType.PARAMETER}) @Retention(RetentionPolicy.RUNTIME) public @interface AddHello { }
import javax.servlet.http.HttpServletRequest;
import lombok.extern.slf4j.Slf4j;
import org.springframework.core.MethodParameter;
import org.springframework.web.bind.support.WebDataBinderFactory;
import org.springframework.web.context.request.NativeWebRequest;
import org.springframework.web.method.support.HandlerMethodArgumentResolver;
import org.springframework.web.method.support.ModelAndViewContainer;
/**
* @date: 2020-09-02
*/
@Slf4j
public class MyResolver implements HandlerMethodArgumentResolver {
private static final String NAME_ATTRIBUTE = "name";
@Override
public boolean supportsParameter(MethodParameter parameter) {
log.info("supportsParameter, {}", parameter);
return parameter.hasParameterAnnotation(AddHello.class);
}
@Override
public Object resolveArgument(MethodParameter parameter, ModelAndViewContainer mavContainer,
NativeWebRequest webRequest, WebDataBinderFactory binderFactory) throws Exception {
HttpServletRequest request = webRequest.getNativeRequest(HttpServletRequest.class);
log.info("resolveArgument, {}", request);
return request == null ? null : "hello, " + request.getParameter(NAME_ATTRIBUTE);
}
}
config(配置類)
import java.util.List;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.method.support.HandlerMethodArgumentResolver;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
/**
* @date: 2020-09-02
*/
@Configuration
public class WebConfig implements WebMvcConfigurer {
@Bean
public FilterRegistrationBean<MyFilter> myFilterRegistrationBean() {
FilterRegistrationBean<MyFilter> registrationBean = new FilterRegistrationBean();
MyFilter i18nFilter = new MyFilter();
registrationBean.setFilter(i18nFilter);
registrationBean.addUrlPatterns("/*");
registrationBean.setOrder(1);
return registrationBean;
}
@Override
public void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(new MyInterceptor());
}
@Override
public void addArgumentResolvers(List<HandlerMethodArgumentResolver> argumentResolvers) {
argumentResolvers.add(new MyResolver());
}
}
import javax.servlet.http.HttpServletRequest;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
/**
* @date: 2020-09-02
*/
@RestController
@RequestMapping("/hello")
public class HelloController {
@GetMapping
public String get(HttpServletRequest request, String name, @AddHello String hello) {
return hello;
}
}
實驗結果
當你訪問 http://127.0.0.1:8443/hello?name=abc
時,會返回 hello, abc
,這是因為Resolver
將資訊注入到hello
引數中了
並且列印的日誌如下,可以看到MyFilter、MyInterceptor和MyResolver都攔截到了。
10758 2020-09-02 21:30:37.272 [http-nio-8443-exec-1] INFO c.e.d.s.a.intercept.MyFilter - filter - request : org.apache.catalina.connector.RequestFacade@27e424a4, response : org.apache.catalina.connector.ResponseFacade@37897bdf
10766 2020-09-02 21:30:37.280 [http-nio-8443-exec-1] INFO c.e.d.s.a.intercept.MyInterceptor - HandlerInterceptorAdapter - request : org.apache.catalina.connector.RequestFacade@27e424a4, response : org.apache.catalina.connector.ResponseFacade@37897bdf
10778 2020-09-02 21:30:37.292 [http-nio-8443-exec-1] INFO c.e.d.s.a.intercept.MyResolver - supportsParameter, method 'get' parameter 1
10783 2020-09-02 21:30:37.297 [http-nio-8443-exec-1] INFO c.e.d.s.a.intercept.MyResolver - supportsParameter, method 'get' parameter 2
10783 2020-09-02 21:30:37.297 [http-nio-8443-exec-1] INFO c.e.d.s.a.intercept.MyResolver - resolveArgument, org.apache.catalina.connector.RequestFacade@27e424a4