Spring MVC上传

╰半橙微兮° 2022-05-21 07:37 179阅读 0赞

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# <table>   <tbody>    <tr>     <td><font>简述</font></td>    </tr>   </tbody>  </table> #

项目中上传和下载是非常常见的功能,如果项目中使用的是Spring MVC,那么实现上传和下载真是很简单咯。

# <table>   <tbody>    <tr>     <td><font>上传</font></td>    </tr>   </tbody>  </table> #

## 1.添加相关jar包的依赖 ##

<dependency>
          <groupId>org.springframework</groupId>
          <artifactId>spring-webmvc</artifactId>
          <version>5.0.7.RELEASE</version>
    </dependency>
    
    <dependency>
          <groupId>commons-fileupload</groupId>
          <artifactId>commons-fileupload</artifactId>
          <version>1.3.3</version>
    </dependency>
    
    <dependency>
          <groupId>javax.servlet</groupId>
          <artifactId>javax.servlet-api</artifactId>
          <version>4.0.1</version>
          <scope>provided</scope>
    </dependency>

**jar包引用说明:**  
使用jsp需要配置视图解析器,上传功能需要配置上传文件解析器,因此需要引用spring-webmvc的jar包,上传文件方法的controller使用时要被加载到IOC容器中,因此需要配置包扫描,包扫描在spring-context包下,这个包已经在spring-webmvc下依赖,所以不需要重复依赖。上传是基于commons-fileupload的,因此需要引用commons-fileupload的jar包

## 2.编写springmvc的配置文件springmvc-config.xml ##

<?xml version="1.0" encoding="UTF-8"?>
    <beans xmlns="http://www.springframework.org/schema/beans"
           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:mvc="http://www.springframework.org/schema/mvc"
           xmlns:context="http://www.springframework.org/schema/context"
           xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd">
        
        <context:component-scan base-package="zh.spring.controller"/>
        
        <mvc:annotation-driven/>
        
        <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
            <property name="maxInMemorySize">
                <value>10485760</value>
            </property>
            <property name="defaultEncoding">
                <value>UTF-8</value>
            </property>
        </bean>
        
        <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
            <property name="prefix" value="WEB-INF/content/"/>
            <property name="suffix" value=".jsp"/>
        </bean>
    </beans>

## 3.配置前端控制器 ##

<?xml version="1.0" encoding="UTF-8"?>
    <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="3.0"
             xmlns="http://java.sun.com/xml/ns/javaee"
             xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
        http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
    
        
        <servlet>
            <servlet-name>FileUpload</servlet-name>
            <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
            <init-param>
                <param-name>contextConfigLocation</param-name>
                <param-value>classpath:springmvc-config.xml</param-value>
            </init-param>
            <load-on-startup>1</load-on-startup>
        </servlet>
        <servlet-mapping>
            <servlet-name>FileUpload</servlet-name>
            <url-pattern>/</url-pattern>
        </servlet-mapping>
    
    </web-app>

## 4.添加jsp文件 ##

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
    <html>
    <head>
        <title>文件上传</title>
    </head>
    <body>
        <h2>文件上传</h2>
    
        <form action="upload" enctype="multipart/form-data" method="post">
            <table>
                <tr>
                    <td>请选择文件:</td>
                    <td><input type="file" name="file"></td>
                </tr>
                <tr>
                    <td><input type="submit"value="上传"></td>
                </tr>
            </table>
        </form>
    </body>
    </html>

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
    <html>
    <head>
        <title>上传成功</title>
    </head>
    <body>
        <h2>恭喜你,上传成功了</h2>
    </body>
    </html>

## 5.Controller方法 ##

package zh.spring.controller;
    
    import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestMethod;
    import org.springframework.web.bind.annotation.RequestParam;
    import org.springframework.web.multipart.MultipartFile;
    
    import javax.servlet.http.HttpServletRequest;
    import java.io.File;
    
    
    @Controller
    public class FileUploadController {
        @RequestMapping("index")
        public String index(){
            return "uploadForm";
        }
    
        @RequestMapping(value = "/upload",method = RequestMethod.POST)
        public String upload(HttpServletRequest request,
                             @RequestParam("file")MultipartFile file) throws Exception{
            if(!file.isEmpty()){
    //            上传文件路径
                String path = request.getServletContext().getRealPath("/images/");
                System.out.println(path);
    //            上传文件名
                String filename = file.getOriginalFilename();
                File filepath = new File(path,filename);
                if(!filepath.getParentFile().exists()){
                    filepath.getParentFile().mkdirs();
                }
    //            将上传文件保存到一个目标文件中
                file.transferTo(new File(path+File.separator+filename));
                return "success";
            }else{
                return "error";
            }
        }
    }

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