摘要：本文主要介绍了在SpringBoot中如何加载XML配置文件，以及如何注册拦截器。

加载XML配置

其实在SpringBoot中加载XML配置有点鸡肋，因为SpringBoot一般是不用XML配置的，但是在这里我们还是说明一下吧。首先我们创建一个SayHello类，但是不为其添加注解。

package com.example.xml;

/**
 * @author: WJZheng
 * @date: 2020/3/17 10:22
 * @description:
 */
public class SayHello {
    public String sayHello() {
        return "hello";
    }
}

然后创建一个XML配置文件

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">

    <bean class="com.example.xml.SayHello" id="sayHello"/>
</beans>

最后再创建一个配置类

package com.example.xml;

import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.ImportResource;

/**
 * @author: WJZheng
 * @date: 2020/3/17 10:24
 * @description:
 */
@Configuration
@ImportResource(locations = "classpath:beans.xml")
public class WebMvcConfig {
}

那么至此XML配置就已经加载完成了，我们再通过单元测试来看看是否成功加载了

package com.example.xml;

import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

@SpringBootTest
class XmlApplicationTests {
    @Autowired
    SayHello sayHello;

    @Test
    void contextLoads() {
        System.out.println(sayHello.sayHello());
    }
}

注册拦截器

首先创建一个自定义拦截器类，然后实现HandlerInterceptor接口

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;

/**
 * @author: WJZheng
 * @date: 2020/3/17 10:29
 * @description:
 */
public class MyInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("preHandle");
        return true;
    }

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

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        System.out.println("afterCompletion");
    }
}

再创建一个配置类来注册自定义的拦截器

package com.example.interceptor;

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;

/**
 * @author: WJZheng
 * @date: 2020/3/17 10:30
 * @description:
 */
@Configuration
public class WebMvcConfig implements WebMvcConfigurer {
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(myInterceptor()).addPathPatterns("/**");
    }

    @Bean
    MyInterceptor myInterceptor(){
        return new MyInterceptor();
    }
}

最后呢创建一个HelloController来进行测试

package com.example.interceptor;

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

/**
 * @author: WJZheng
 * @date: 2020/3/17 10:47
 * @description:
 */

@RestController
public class HelloController {
    @GetMapping("/hello")
    public String hello(){
        return "hello";
    }
}