springMVC的文件上传例子

1.首先创建Maven Web项目，添加依赖.

<dependencies>
  <dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-webmvc</artifactId>
    <version>5.0.7.RELEASE</version>
  </dependency>
  <dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>javax.servlet-api</artifactId>
    <version>4.0.0-b05</version>
  </dependency>
  <dependency>
    <groupId>commons-fileupload</groupId>
    <artifactId>commons-fileupload</artifactId>
    <version>1.3.3</version>
  </dependency>
</dependencies>

2.修改web.xml.

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4"
         xmlns="http://java.sun.com/xml/ns/j2ee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">

    <servlet>
        <servlet-name>springmvc</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:springmvc.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>springmvc</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>


</web-app>

3.resources文件夹下创建springmvc.xml.

这里注意如果不添加静态资源的访问的话，是无法访问图片资源的.因为配置springmvc的servlet的时候拦截了所有的资源.

<?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:context="http://www.springframework.org/schema/context"
               xmlns:mvc="http://www.springframework.org/schema/mvc"
               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">

<!--开启注解识别-->
<mvc:annotation-driven />
<!--开通静态资源的访问-->
<mvc:default-servlet-handler />

<context:component-scan base-package="com.byh.controller"/>

<bean id="irViewResolver"
      class="org.springframework.web.servlet.view.InternalResourceViewResolver">
    <property name="prefix" value="/WEB-INF/page/" />
    <property name="suffix" value=".jsp" />
</bean>

<!--开放对上传功能的支持-->
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
    <!-- 指定所上传文件的总大小,单位字节。注意maxUploadSize属性的限制不是针对单个文件，而是所有文件的容量之和 -->
    <property name="maxUploadSize" value="10240000" />
</bean>

</beans>

4.在WEB-INF/page/下创建uoload.jsp，这里input标签限制了可上传文件的类型为图片类型

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<form action="/upload" method="post" enctype="multipart/form-data">
    上传文件：<input type="file" name="image" accept="image/*"/>
    <input type="submit" value="上传">
</form>

</body>
</html>

和show.jsp.

<%@ page contentType="text/html;charset=UTF-8" language="java" isELIgnored="false" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<div>
    <img src="image/${imagename}">
</div>
</body>
</html>

5.编写文件上传的工具类,注意这的属性名image一定要和input里面的name属性的值相同.

package com.byh.utils;

import org.springframework.web.multipart.MultipartFile;

public class UploadUtil {
    /*
        这里的字段image必须和上传页面upload.jsp中的image
        <input type="file" name="image" accept="image/*" />一样的名字
    */
    private MultipartFile image;

    public MultipartFile getImage() {
        return image;
    }

    public void setImage(MultipartFile image) {
        this.image = image;
    }
}

6.编写控制器.

package com.byh.controller;

import com.byh.utils.UploadUtil;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;

import javax.servlet.http.HttpServletRequest;
import java.io.File;
import java.io.IOException;
import java.util.Date;
import java.util.Random;

@Controller
public class UploadController {

    @RequestMapping("/upload")
    public String uploadDemo(HttpServletRequest request, UploadUtil upload, Model model) throws IOException {
        Random random = new Random();
        int num = random.nextInt(99);
        String num1 = String.valueOf(num);
        String imageName = num1+".jpg";

        File file = new File(request.getServletContext().getRealPath("/image"),imageName);
        file.getParentFile().mkdirs();
        upload.getImage().transferTo(file);
        model.addAttribute("imagename",imageName);
        return "show";
    }

    @RequestMapping("/uploadImage")
    public String uoload(){
        return "upload";
    }

}

7.测试。

输入http://localhost:8080/uploadImage

点击上传后可以看到图片。我这里图片保存在D:\spring\springmvc01\target\springmvc01-1.0-SNAPSHOT\image。具体路径根据个人而定。

springMVC的文件上传例子