SpringMVC第四课

最新推荐文章于 2022-12-03 20:11:04 发布

原创最新推荐文章于 2022-12-03 20:11:04 发布 · 144 阅读

0 ·

CC 4.0 BY-SA版权

文章标签：

#放行静态资源 #文件上传 #拦截器

本文为SpringMVC第四课内容，介绍了放行静态资源，因dispatcher - servlet拦截路径问题需放行静态资源；还提及文件上传；重点讲解了拦截器，要实现HandlerInterceptor接口，重写三个方法，常用preHandle，且需在dispatcher - servlet.xml中配置拦截路径。

SpringMVC第四课

放行静态资源

因为dispatcher-servlet一般配置的拦截路径是“/”会把除了.jsp的文件全部拦截，所以需要把静态资源放行

<!-- 放行静态资源, mapping匹配你请求的URI； location指定静态资源的位置(建议前后面都加/) -->
<mvc:resources mapping="/private/views/**" location="WEB-INF/views/,classpath:/static/" />

文件上传

2.5

<!--添加依赖-->
<dependency>
      <groupId>commons-fileupload</groupId>
      <artifactId>commons-fileupload</artifactId>
      <version>1.3.3</version>
    </dependency>

<!--dispatcher-servlet.xml中配置bean-->
<bean name="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"/>

<!--案例：-->
	@ResponseBody
    @RequestMapping("/upload2.5")
    public String upload(@RequestParam("myFile") MultipartFile file){
        try {
            file.transferTo(new File("D:/"+file.getOriginalFilename()));
            return "上传成功";
        } catch (IOException e) {
            e.printStackTrace();
            return "上传失败";
        }
    }

3.0

<!--dispatcher-servlet.xml中配置bean-->
    <bean name="multipartResolver" class="org.springframework.web.multipart.support.StandardServletMultipartResolver"/>
    
<!--在web.xml中的servlet标签内开启Servlet3.0文件上传支持-->
<multipart-config />
        
<!--案例：-->
	@ResponseBody
    @RequestMapping("/upload2.5")
    public String upload(@RequestParam("myFile") MultipartFile file){
        try {
            file.transferTo(new File("D:/"+file.getOriginalFilename()));
            return "上传成功";
        } catch (IOException e) {
            e.printStackTrace();
            return "上传失败";
        }
    }

拦截器

实现HandlerInterceptor接口，重写preHandle,postHandle,afterCompletion三个方法，一般preHandle最常用

package com.lanou3g.springmvc.interceptor;

import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
 * @author hmt
 * @date 2019/7/4 14:32
 */
public class TestInterceptor implements HandlerInterceptor{
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("pre");
        return true;
    }
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        System.out.println("post");
    }
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        System.out.println("after");
    }
}

在dispatcher-servlet.xml中配置拦截路径

<mvc:interceptors>
    <!-- 通过<bean>的形式添加interceptor，默认拦截所有请求 -->
    <bean class="com.lanou3g.springmvc.interceptor.TestInterceptor" />
    <!-- 通过<mvc:interceptor>配置，可以进一步拦截哪些路径和不拦截哪些路径 -->
    <!--<mvc:interceptor>
        <mvc:mapping path="/*" />
        <mvc:exclude-mapping path="/test" />
        <bean class="com.lanou3g.springmvc.interceptor.LoginInterceptor" />
    </mvc:interceptor>-->
</mvc:interceptors>