拦截器是SpringMVC的技术
过滤器的Servlet的技术
先过过滤器，过滤器过完才到DispatcherServlet；
拦截器归属于SpringMVC，只可能拦SpringMVC的东西；
拦截器说白了就是为了增强，可以在请求前进行增强，也可以在请求后进行增强，但是不一定同时在前后都增强。
区别
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.2.7.RELEASE</version>
</parent>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
</dependencies>
package com.test.filtertest.inter;
import org.springframework.stereotype.Component;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* 拦截器
*
* @author: zhangzengxiu
* @createDate: 2022/4/22
*/
@Component
public class TestInter1 implements HandlerInterceptor {
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
System.out.println("TestInter1 preHandle...");
return true;
}
@Override
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
System.out.println("TestInter1 postHandle...");
}
@Override
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
System.out.println("TestInter1 afterCompletion...");
}
}
Interceptor拦截器要注册
package com.test.filtertest.config;
import com.test.filtertest.inter.TestInter1;
import com.test.filtertest.inter.TestInter2;
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;
/**
* @author zhangzengxiu
* @date 2022/4/22
*/
@Configuration
public class WebConfig implements WebMvcConfigurer {
@Autowired
private TestInter1 testInter1;
@Autowired
private TestInter2 testInter2;
@Override
public void addInterceptors(InterceptorRegistry registry) {
//默认/** 拦截所有请求
registry.addInterceptor(testInter1).addPathPatterns("/**");
registry.addInterceptor(testInter2);
}
}
拦截顺序
多拦截器拦截顺序取决于registry的注册顺序
package com.test.filtertest.filter;
import org.springframework.core.annotation.Order;
import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import java.io.IOException;
/**
* @author zhangzengxiu
* @date 2022/4/22
*/
@WebFilter(filterName = "TestFilter1", urlPatterns = "/*")
//@Order(2) //filter这样定义拦截顺序无效，还是会按照类名去拦截
public class TestFilter1 implements Filter {
@Override
public void init(FilterConfig filterConfig) throws ServletException {
}
@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
System.out.println("TestFilter1 filter before ...");
filterChain.doFilter(servletRequest, servletResponse);
System.out.println("TestFilter1 filter after ...");
}
@Override
public void destroy() {
}
}
加了@WebFilter注解的过滤器要生效，需要在启动类上加一个注解@ServletComponentScan
如果要设置过滤顺序的话，在Filter上添加@Order 不会生效，还是会默认根据Filter过滤器的类名去进行过滤。
如果想要指定拦截顺序，需要添加一个配置类，通过设置Order的值去设置过滤顺序，Order数值越小优先级越高
package com.test.config;
import com.test.filter.TestFilter1;
import com.test.filter.TestFilter2;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import javax.servlet.Filter;
/**
* filter过滤器配置
*
* @author: zhangzengxiu
* @createDate: 2022/4/24
*/
@Configuration
public class FilterConfig {
@Bean
public FilterRegistrationBean testFilter1() {
FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean();
Filter testFilter1 = new TestFilter1();
filterRegistrationBean.setFilter(testFilter1);
filterRegistrationBean.addUrlPatterns("/*");
filterRegistrationBean.setName("testFilter1");
filterRegistrationBean.setOrder(2);//指定过滤顺序，数值越小优先级越高
return filterRegistrationBean;
}
@Bean
public FilterRegistrationBean testFilter2() {
FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean();
Filter testFilter2 = new TestFilter2();
filterRegistrationBean.setFilter(testFilter2);
filterRegistrationBean.setName("testFilter2");
filterRegistrationBean.addUrlPatterns("/*");
filterRegistrationBean.setOrder(1);//指定过滤顺序，数值越小优先级越高
return filterRegistrationBean;
}
}1、同时原本Filter过滤器上的@WebFilter(filterName = “TestFilter1”, urlPatterns = “/*”)
这个注解最好去掉，否则bean重复会报错，要么bean名称不要重复，换个名称。但是不去掉的话@ServletComponentScan也要被保留，最好统一格式，只使用config配置。
2、启动类上的@ServletComponentScan 注解也不需要了，可以去掉了，因为不用扫描@WebFilter注解了。但是如果@WebFilter还保留了，那么就不能去掉了。不然加了@WebFilter的过滤器就不会生效了，因为没扫到。
