java过滤器拦截器区别 通过实例解析java过滤器和拦截器的区别
未月廿三 人气:0区别
1.使用范围和规范不同
filter是servlet规范规定的,只能用在web程序中.
拦截器即可以用在web程序中, 也可以用于application, swing程序中, 是Spring容器内的, 是Spring框架支持的
2.触发时机不同
顺序: Filter-->Servlet-->Interceptor-->Controller
- 过滤器是在请求进入容器后,但请求进入servlet之前进行预处理的。请求结束返回也是,是在servlet处理完后,返回给前端之前过滤器处理。
- 拦截器是方法到达Controller层之前生效的
3.过滤器的实现基于回调函数。而拦截器(代理模式)的实现基于反射,代理分静态代理和动态代理,动态代理是拦截器的简单实现。
何时使用拦截器?何时使用过滤器?
- 如果是非spring项目,那么拦截器不能用,只能使用过滤器。
- 如果是处理controller前后,既可以使用拦截器也可以使用过滤器。
- 如果是处理dispaterServlet前后,只能使用过滤器。
4.在action的生命周期中,拦截器可以多次被调用,而过滤器只能在容器初始化时被调用一次。
5.拦截器可以访问action上下文、值栈里的对象,而过滤器不能访问。
6.拦截器只能对action请求起作用,而过滤器则可以对几乎所有的请求起作用。
7.拦截器可以获取IOC容器中的各个bean,而过滤器就不行,在拦截器里注入一个service,可以调用业务逻辑。
SpringBoot使用过滤器
两种方式:
1、使用spring boot提供的FilterRegistrationBean注册Filter
2、使用原生servlet注解定义Filter
两种方式的本质都是一样的,都是去FilterRegistrationBean注册自定义Filter
封装Filter
package com.theeternity.common.baseFilter; import javax.servlet.Filter; /** * @program: ApiBoot * @description: 封装Filter * @author: TheEternity Zhang * @create: 2019-02-17 13:08 */ public interface MappingFilter extends Filter { String[] addUrlPatterns(); int order(); }
自定义Filter
package com.theeternity.beans.filterConfig; import com.theeternity.common.baseFilter.MappingFilter; import lombok.extern.slf4j.Slf4j; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import javax.servlet.*; import javax.servlet.FilterConfig; import java.io.IOException; /** * @program: ApiBoot * @description: 权限过滤器 * @author: TheEternity Zhang * @create: 2019-02-17 13:14 */ public class AuthFilter implements MappingFilter { @Override public String[] addUrlPatterns() { return new String[]{"/*"}; } @Override public int order() { return 0; } @Override public void init(FilterConfig filterConfig) throws ServletException { } @Override public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException { filterChain.doFilter(servletRequest,servletResponse); } @Override public void destroy() { } }
注册过滤器
package com.theeternity.beans.filterConfig; import org.springframework.boot.web.servlet.FilterRegistrationBean; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; /** * @program: ApiBoot * @description: 注册过滤器 * @author: TheEternity Zhang * @create: 2019-02-17 13:10 */ @Configuration public class FilterConfig { @Bean public FilterRegistrationBean registFilter() { FilterRegistrationBean registration = new FilterRegistrationBean(); AuthFilter authFilter=new AuthFilter(); registration.setFilter(authFilter); registration.addUrlPatterns(authFilter.addUrlPatterns()); registration.setOrder(authFilter.order()); registration.setName("AuthFilter"); return registration; } }
SpringBoot使用拦截器
封装Interceptor
package com.theeternity.common.baseInterceptor; import org.springframework.web.servlet.HandlerInterceptor; /** * @program: ApiBoot * @description: 封装Interceptor * @author: TheEternity Zhang * @create: 2019-02-15 17:49 */ public interface MappingInterceptor extends HandlerInterceptor { String[] addPathPatterns(); String[] excludePathPatterns(); int order(); }
自定义Interceptor
package com.theeternity.beans.interceptorConfig; import com.theeternity.common.baseInterceptor.MappingInterceptor; import org.springframework.stereotype.Component; import org.springframework.web.servlet.ModelAndView; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; /** * @program: BoxApi * @description: 跨域拦截器 * @author: tonyzhang * @create: 2018-12-21 14:44 */ @Component public class CrossOriginInterceptor implements MappingInterceptor { @Override public String[] addPathPatterns() { return new String[]{"/**"}; } @Override public String[] excludePathPatterns() { return new String[0]; } @Override public int order() { return 0; } @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception { logger.info("允许的头信息"+request.getHeader("Origin")); response.setHeader("Access-Control-Allow-Origin", "*"); response.setHeader("Access-Control-Allow-Methods", "*"); response.setHeader("Access-Control-Max-Age", "3600"); response.setHeader("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept"); //是否允许浏览器携带用户身份信息(cookie) response.setHeader("Access-Control-Allow-Credentials","true"); return true; } @Override public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception { } @Override public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler,Exception ex) throws Exception { } }
注册Interceptor
package com.theeternity.beans.interceptorConfig; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.context.annotation.Configuration; import org.springframework.web.servlet.config.annotation.InterceptorRegistry; import org.springframework.web.servlet.config.annotation.WebMvcConfigurer; /** * @program: ApiBoot * @description: 拦截器注册 * @author: TheEternity Zhang * @create: 2019-02-15 17:55 */ @Configuration public class InterceptorConfig implements WebMvcConfigurer { @Autowired private CrossOriginInterceptor crossOriginInterceptor; @Override public void addInterceptors(InterceptorRegistry registry) { registry.addInterceptor(crossOriginInterceptor).addPathPatterns(crossOriginInterceptor.addPathPatterns()); } }
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