Spring MVC 文件上传示例

2025 年 3 月 25 日 | 阅读 2 分钟

Spring MVC 提供了简单的方式来上传文件，可以是图像或其他文件。让我们看一个使用 Spring MVC 上传文件的简单示例。

所需 Jar 文件

要运行此示例，您需要加载

Spring Core jar 文件
Spring Web jar 文件
commons-fileupload.jar 和 commons-io.jar 文件

1) 下载所有 Spring 的 jar 文件，包括 core, web, aop, mvc, j2ee, remoting, oxm, jdbc, orm 等。

2) 下载 commons-io.jar

3) 下载 commons-fileupload.jar

Spring MVC 文件上传步骤（MVC 之外）

1) 添加 commons-io 和 fileupload.jar 文件

2) 在 spring-servlet.xml 中添加 CommonsMultipartResolver 的条目

<bean id="multipartResolver" 
class="org.springframework.web.multipart.commons.CommonsMultipartResolver"/>

3) 创建表单来提交文件。Method 名称必须是 "post"，enctype 是 "multiple/form-data"。

<form action="savefile" method="post" enctype="multipart/form-data">
Select File: <input type="file" name="file"/>
<input type="submit" value="Upload File"/>
</form>

4) 在 Controller 中使用 CommonsMultipartFile 类。

@RequestMapping(value="/savefile",method=RequestMethod.POST)
public ModelAndView upload(@RequestParam CommonsMultipartFile file,HttpSession session){
		String path=session.getServletContext().getRealPath("/");
		String filename=file.getOriginalFilename();
		
		System.out.println(path+" "+filename);
		try{
		byte barr[]=file.getBytes();
		
		BufferedOutputStream bout=new BufferedOutputStream(
                 new FileOutputStream(path+"/"+filename));
		bout.write(barr);
		bout.flush();
		bout.close();
		
		}catch(Exception e){System.out.println(e);}
		return new ModelAndView("upload-success","filename",path+"/"+filename);
	}

5) 在 JSP 中显示图像。

<h1>Upload Success</h1>
<img src="${filename}"/>

Spring MVC 文件上传示例

创建 images 目录

在您的项目中创建 "images" 目录，因为我们正在编写代码将所有文件保存在 "/images" 目录下。

index.jsp

Emp.java

package com.javatpoint;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.ModelAttribute;
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.commons.CommonsMultipartFile;
import org.springframework.web.servlet.ModelAndView;

@Controller
public class HelloController {
	private static final String UPLOAD_DIRECTORY ="/images";
	
	@RequestMapping("uploadform")
	public ModelAndView uploadForm(){
		return new ModelAndView("uploadform");	
	}
	
	@RequestMapping(value="savefile",method=RequestMethod.POST)
	public ModelAndView saveimage( @RequestParam CommonsMultipartFile file,
           HttpSession session) throws Exception{

	ServletContext context = session.getServletContext();
	String path = context.getRealPath(UPLOAD_DIRECTORY);
	String filename = file.getOriginalFilename();

	System.out.println(path+" "+filename);	    

	byte[] bytes = file.getBytes();
	BufferedOutputStream stream =new BufferedOutputStream(new FileOutputStream(
         new File(path + File.separator + filename)));
	stream.write(bytes);
	stream.flush();
	stream.close();
	     
	return new ModelAndView("uploadform","filesuccess","File successfully saved!");
	}
}

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" 
	xmlns="http://java.sun.com/xml/ns/javaee" 
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
	http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
 <servlet>
	<servlet-name>spring</servlet-name>
	<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
	<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
	<servlet-name>spring</servlet-name>
	<url-pattern>/</url-pattern>
</servlet-mapping>
</web-app>

spring-servlet.xml

在这里，您需要为 CommonsMultipartResolver 创建一个 bean。

<?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:p="http://www.springframework.org/schema/p"  
    xmlns:context="http://www.springframework.org/schema/context"  
    xsi:schemaLocation="http://www.springframework.org/schema/beans  
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd  
http://www.springframework.org/schema/context  
http://www.springframework.org/schema/context/spring-context-3.0.xsd">  

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

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

<bean id="multipartResolver" 
class="org.springframework.web.multipart.commons.CommonsMultipartResolver"/>

</beans>

uploadform.jsp

在这里，表单必须是 method="post" 且 enctype="multipart/form-data"。

<%@taglib uri="http://www.springframework.org/tags/form" prefix="form"%>
 
<!DOCTYPE html>
<html>
 <head>
 <title>Image File Upload</title>
 </head>
 <body>
<h1>File Upload Example - JavaTpoint</h1>

<h3 style="color:red">${filesuccess}</h3>
<form:form method="post" action="savefile" enctype="multipart/form-data">
<p><label for="image">Choose Image</label></p>
<p><input name="file" id="fileToUpload" type="file" /></p>
<p><input type="submit" value="Upload"></p>
</form:form>
</body>
</html>