SpringBoot 过滤器与拦截器实例演示
作者：宇智波波奶茶
本文通过示例代码给大家讲解SpringBoot 过滤器与拦截器的相关知识，本文给大家介绍的非常详细，对大家的学习或工作具有一定的参考借鉴价值，需要的朋友参考下吧
SpringBoot中的过滤器拦截器操作与springmvc中的几乎一样所以这里也不过多介绍了，下面举两个简单的栗子演示一下
1、过滤器
1 创建过滤器类LoginFilter,实现servlet包下的Filter接口（包不要导错），加入注解WebFilter
package com.example.filter;
import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
@WebFilter(urlPatterns = "/filter/*")
public class LoginFilter implements Filter {
@Override
public void init(FilterConfig filterConfig) throws ServletException {
System.out.println("初始化拦截器");
}
@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
System.out.println("LoginFilter");
HttpServletRequest request = (HttpServletRequest)servletRequest;
HttpServletResponse response = (HttpServletResponse)servletResponse;
//放行
filterChain.doFilter(request,response);
}
@Override
public void destroy() {
System.out.println("拦截器销毁");
}
}
2 创建测试类LoginCotroller
package com.example.controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
@RequestMapping("/filter")
public class FilterController {
@RequestMapping("/login")
public String login(){
System.out.println("登录");
return "login";
}
}
3 在启动类上加注解
package com.example;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.ServletComponentScan;
@SpringBootApplication
@ServletComponentScan
//Servlet、Filter、Listener可以直接通过@WebServlet、@WebFilter、@WebListener注解自动注册
public class DemoApplication {
public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
}
}
4 启动测试，启动的时候可以看到Filter调用init方法初始化
接着访问可以看到页面输出
控制台打印出拦截器中的语句
2、拦截器
1 创建自定义拦截器
package com.example.interceptor;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class MyInterceptor implements HandlerInterceptor {
//进入controller方法之前调用的
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
System.out.println("preHandle");
return true;//true表示放行 false表示不放行
}
//调用完controller之后，视图渲染层之前
@Override
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
System.out.println("postHandle");
}
//页面跳转之后，整个流程执行之后，一般用于资源的清理
@Override
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
System.out.println("afterCompletion");
}
}
2 创建拦截器配置类，注意要加上配置类的注解
package com.example.config;
import com.example.interceptor.MyInterceptor;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
@Configuration
public class MyInterceptorConfig implements WebMvcConfigurer {
@Override
public void addInterceptors(InterceptorRegistry registry) {
//设置拦截器并指定拦截路径
registry.addInterceptor(new MyInterceptor()).addPathPatterns("/interceptor/*");
//registry.addInterceptor(new MyInterceptor()).addPathPatterns("/**");//拦截所有
//registry.addInterceptor(new MyInterceptor()).addPathPatterns("/**").excludePathPatterns("/test");//指定不拦截
//添加自定义拦截器
WebMvcConfigurer.super.addInterceptors(registry);
}
}
3 创建LoginController测试类
package com.example.controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
@RequestMapping("/interceptor")
public class InterceptorController {
@RequestMapping("login")
public String login(){
System.out.println("Interceptor-Login");
return "login";
}
}
4 运行访问，查看效果
控制台输出如下
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