一：基础知识
1.通过FilterRegistrationBean实例注册，该方法能够设置过滤器之间的优先级
2.为了演示优先级，这里创建2个测试过滤器类：Test1Filter、Test2Filter
通过实现javax.servlet.Filter接口，覆盖其doFilter(ServletRequest arg0, ServletResponse arg1, FilterChain arg2)方法，决定拦截或放行
public class Test1Filter implements Filter {
@Override
public void doFilter(ServletRequest arg0, ServletResponse arg1, FilterChain arg2)
throws IOException, ServletException {
// TODO Auto-generated method stub
HttpServletRequest request=(HttpServletRequest)arg0;
System.out.println("自定义过滤器filter1触发,拦截url:"+request.getRequestURI());
arg2.doFilter(arg0,arg1);
}
}
public class Test2Filter implements Filter {
@Override
public void doFilter(ServletRequest arg0, ServletResponse arg1, FilterChain arg2)
throws IOException, ServletException {
// TODO Auto-generated method stub
HttpServletRequest request=(HttpServletRequest)arg0;
System.out.println("自定义过滤器filter2触发,拦截url:"+request.getRequestURI());
arg2.doFilter(arg0,arg1);
}
}
通过在springboot的configuration中配置不同的FilterRegistrationBean实例，来注册自定义过滤器
这里创建一个configuration类
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import com.example.demo.filter.Test1Filter;
import com.example.demo.filter.Test2Filter;
@Configuration
public class DemoConfiguration {
@Bean
public FilterRegistrationBean<Test1Filter> RegistTest1(){
//通过FilterRegistrationBean实例设置优先级可以生效
//通过@WebFilter无效
FilterRegistrationBean<Test1Filter> bean = new FilterRegistrationBean<Test1Filter>();
bean.setFilter(new Test1Filter());//注册自定义过滤器
bean.setName("flilter1");//过滤器名称
bean.addUrlPatterns("/*");//过滤所有路径
bean.setOrder(1);//优先级，最顶级
return bean;
}
@Bean
public FilterRegistrationBean<Test2Filter> RegistTest2(){
//通过FilterRegistrationBean实例设置优先级可以生效
//通过@WebFilter无效
FilterRegistrationBean<Test2Filter> bean = new FilterRegistrationBean<Test2Filter>();
bean.setFilter(new Test2Filter());//注册自定义过滤器
bean.setName("flilter2");//过滤器名称
bean.addUrlPatterns("/test/*");//过滤所有路径
bean.setOrder(6);//优先级，越低越优先
return bean;
}
}
其中
1第一个bean拦截所有路径，而第二个只拦截/test/*路径
2第一个bean优先级设置了1，而第二个设置了6，越低越优先，所以过滤器1应该在过滤器2前面拦截
运行springboot，访问/test/*请求如下图，再访问/v请求如下图只拦截了过滤器1，而过滤器2路径不匹配
以上原文地址：spring boot过滤器FilterRegistrationBean - 稚语希听 - 博客园
二：实战练习
1.管理员过滤器
package com.imooc.mall.filter;
import com.imooc.mall.common.ApiRestResponse;
import com.imooc.mall.common.Constant;
import com.imooc.mall.exception.ImoocMallExceptionEnum;
import com.imooc.mall.model.pojo.Category;
import com.imooc.mall.model.pojo.User;
import com.imooc.mall.service.UserService;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpServletResponseWrapper;
import javax.servlet.http.HttpSession;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.annotation.Autowired;
/**
* 描述： 管理员校验过滤器
*/
public class AdminFilter implements Filter {
@Autowired
UserService userService;
@Override
public void init(FilterConfig filterConfig) throws ServletException {
}
@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse,
FilterChain filterChain) throws IOException, ServletException {
HttpServletRequest request = (HttpServletRequest) servletRequest;
HttpSession session = request.getSession();
User currentUser = (User) session.getAttribute(Constant.IMOOC_MALL_USER);
if (currentUser == null) {
PrintWriter out = new HttpServletResponseWrapper(
(HttpServletResponse) servletResponse).getWriter();
out.write("{\n"
+ " \"status\": 10007,\n"
+ " \"msg\": \"NEED_LOGIN\",\n"
+ " \"data\": null\n"
+ "}");
out.flush();
out.close();
return;
}
//校验是否是管理员
boolean adminRole = userService.checkAdminRole(currentUser);
if (adminRole) {
filterChain.doFilter(servletRequest, servletResponse);
} else {
PrintWriter out = new HttpServletResponseWrapper(
(HttpServletResponse) servletResponse).getWriter();
out.write("{\n"
+ " \"status\": 10009,\n"
+ " \"msg\": \"NEED_ADMIN\",\n"
+ " \"data\": null\n"
+ "}");
out.flush();
out.close();
}
}
@Override
public void destroy() {
}
}
2.管理员过滤器配置
package com.imooc.mall.config;
import com.imooc.mall.filter.AdminFilter;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
/**
* 描述： Admin过滤器的配置
*/
@Configuration
public class AdminFilterConfig {
@Bean
public AdminFilter adminFilter() {
return new AdminFilter();
}
@Bean(name = "adminFilterConf")
public FilterRegistrationBean adminFilterConfig() {
FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean();
filterRegistrationBean.setFilter(adminFilter());
filterRegistrationBean.addUrlPatterns("/admin/category/*");
filterRegistrationBean.addUrlPatterns("/admin/product/*");
filterRegistrationBean.addUrlPatterns("/admin/order/*");
filterRegistrationBean.setName("adminFilterConf");
return filterRegistrationBean;
}
}