springboot自定义拦截器

1、实现HandlerInterceptor接口或继承HandlerInterceptorAdapter类自定义拦截器

本文采用实现HandlerInterceptor接口

import org.apache.logging.log4j.util.Strings;
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 {


    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("拦截方法访问之前调用");
        System.out.println(request.getRequestURI() + "被MyInterceptor拦截器拦截");
        String token = request.getHeader("token");
        if(Strings.isEmpty(token)){
            //  如果token为空转到/api/open/unlogin接口，即模拟未登录跳转到登录接口
            request.getRequestDispatcher("/api/open/unlogin").forward(request,response);
            return false;
        }
        return true;    //不拦截，放行
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        System.out.println("访问之后调用");
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        System.out.println("整个流程结束之后调用");
    }
}

2、配置类对添加拦截器

import com.scitech.interceptor.MyInterceptor;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

@Configuration  //配置类加上@Configuration注解
public class WebApplicationConfig implements WebMvcConfigurer {

    @Value("${open.url}")	//开放性url，此处为/**/open/**
    private String openUrl;

    @Bean
    public MyInterceptor getMyInterceptor(){
        return new MyInterceptor();
    }

    /**
     * 添加拦截器
     * 对所有除了openUrl开放性接口进行拦截
     * @param registry
     */
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        //添加拦截器方法                               添加拦截策略（路径）          放弃开放性白名单
        registry.addInterceptor(getMyInterceptor()).addPathPatterns("/api/**").excludePathPatterns(openUrl);
    }
}

3、对拦截器进行测试

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/api")
public class TestController {

	//调用该接口时，有token则进入该接口，没有token就跳转到/api/open/unlogin
    @GetMapping("/abc")
    public String hello2(){	
        return "不是开放性接口，需要拦截，有token时显示";
    }

    @GetMapping("/open/unlogin")	//开放性接口，不需要拦截
    public String hello3(){
        return "unlogin";
    }
}

调用/api/abc接口：

添加token时结果：

不加token时结果：