Spring MVC 4 文件上传下载 Hibernate+MySQL例子（带源码）

原文地址：http://websystique.com/springmvc/spring-mvc-4-file-upload-example-using-commons-fileupload/

本文将实现使用SpringMultipartResolver实现单个或者多文件上传.

Spring提供内置multipart 支持用来处理web 应用中文件上传。

注意:
multipart 是 enctype=”multipart/form-data”的内容.

简单预览

Spring使用MultiPartResolver接口实现文件上传.

1. 使用Apache Commons . Spring CommonsMultipartResolver 使用Apache
Commons FileUpload 实现 MultipartResolver . 它需要apache 的commons-fileupload.jar 包. 虽然不针对Servlet 3但是Servlet
3.x容器中使用也没问题。
2. 要想用Servlet 3.0 multipart 请求需要配置[XML
or JavaConfig]..
XML 设置, 你需要在 web.xml的"multipart-config" 节点配置DispatcherServlet.
如果是Annoataion/JavaConfig配置, 在DispatcherServlet 注册javax.servlet.MultipartConfigElement
.或者使用 @MultipartConfig定义servlet.

本文主要用CommonsMultipartResolver . 下一篇文章使用Servlet 3.0 来实现文件上传.

步骤:

创建一个CommonsMultipartResolver类型的bean , 指明和文件上传相关的配置文件
在类路径包含 Apache Commons commons-fileupload.jar文件.
表单中要含有[enctype=”multipart/form-data”]
处理文件的input类型应该是 ‘file’

类似如下:

<form method="POST" enctype="multipart/form-data" >
		....
			<input type="file" id="file" />
		....
			<input type="submit" value="Upload">
</form>

完整的例子

用到的技术和软件

Spring 4.2.0.RELEASE
Apache Commons fille-upload 1.3.1
validation-api 1.1.0.Final
Bootstrap v3.3.2
Maven 3
JDK 1.7
Tomcat 8.0.21
Eclipse JUNO Service Release 2

项目结构

在pom.xml文件中声明依赖

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.websystique.springmvc</groupId>
  <artifactId>Spring4MVCFileUploadCommonsExample</artifactId>
  <packaging>war</packaging>
  <version>1.0.0</version>
  <name>Spring4MVCFileUploadCommonsExample Maven Webapp</name>
  <url>http://maven.apache.org</url>

    <properties>
		<springframework.version>4.2.0.RELEASE</springframework.version>
	</properties>

	<dependencies>
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-webmvc</artifactId>
			<version>${springframework.version}</version>
		</dependency>

		<dependency>
			<groupId>commons-fileupload</groupId>
			<artifactId>commons-fileupload</artifactId>
			<version>1.3.1</version>
		</dependency>

		<!-- For user input validation -->
		<dependency>
            <groupId>javax.validation</groupId>
            <artifactId>validation-api</artifactId>
            <version>1.1.0.Final</version>
        </dependency>

		<dependency>
			<groupId>javax.servlet</groupId>
			<artifactId>javax.servlet-api</artifactId>
			<version>3.1.0</version>
		</dependency>
		<dependency>
			<groupId>javax.servlet</groupId>
			<artifactId>jstl</artifactId>
			<version>1.2</version>
		</dependency>
	</dependencies>

	<build>
		<pluginManagement>
			<plugins>
				<plugin>
					<groupId>org.apache.maven.plugins</groupId>
					<artifactId>maven-compiler-plugin</artifactId>
					<version>3.2</version>
					<configuration>
						<source>1.7</source>
						<target>1.7</target>
					</configuration>
				</plugin>
				<plugin>
					<groupId>org.apache.maven.plugins</groupId>
					<artifactId>maven-war-plugin</artifactId>
					<version>2.4</version>
					<configuration>
						<warSourceDirectory>src/main/webapp</warSourceDirectory>
						<warName>Spring4MVCFileUploadCommonsExample</warName>
						<failOnMissingWebXml>false</failOnMissingWebXml>
					</configuration>
				</plugin>
			</plugins>
		</pluginManagement>

		<finalName>Spring4MVCFileUploadCommonsExample</finalName>
	</build>
</project>

创建配置类

package com.websystique.springmvc.configuration;

import java.io.IOException;

import org.springframework.context.MessageSource;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.support.ResourceBundleMessageSource;
import org.springframework.web.multipart.commons.CommonsMultipartResolver;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.ViewResolverRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
import org.springframework.web.servlet.view.InternalResourceViewResolver;
import org.springframework.web.servlet.view.JstlView;

@Configuration
@EnableWebMvc
@ComponentScan(basePackages = "com.websystique.springmvc")
public class HelloWorldConfiguration extends WebMvcConfigurerAdapter{

	@Bean(name="multipartResolver")
	public CommonsMultipartResolver getResolver() throws IOException{
		CommonsMultipartResolver resolver = new CommonsMultipartResolver();

		//Set the maximum allowed size (in bytes) for each individual file.
		resolver.setMaxUploadSizePerFile(5242880);//5MB

		//You may also set other available properties.

		return resolver;
	}

	@Override
    public void configureViewResolvers(ViewResolverRegistry registry) {
        InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();
        viewResolver.setViewClass(JstlView.class);
        viewResolver.setPrefix("/WEB-INF/views/");
        viewResolver.setSuffix(".jsp");
        registry.viewResolver(viewResolver);
    }

	@Bean
    public MessageSource messageSource() {
        ResourceBundleMessageSource messageSource = new ResourceBundleMessageSource();
        messageSource.setBasename("messages");
        return messageSource;
    }

    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/static/**").addResourceLocations("/static/");
    }

}

配置里面最重要的是 CommonsMultipartResolver Bean.
它是Apache Commons FileUpload里面的 MultipartResolver接口的实现。

你可以设置文件最大限制，headerEncoding 等，我们例子里只限制5M。

对应的XML配置形式：

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
    http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd
    http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd">

    <context:component-scan base-package="com.websystique.springmvc" />
    <mvc:annotation-driven />

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

    	<!-- one of the several properties available; the maximum file size in bytes -->
        <property name="maxUploadSizePerFile" value="5242880"/>
    </bean>

    <mvc:resources mapping="/static/**" location="/static/" />
    <mvc:default-servlet-handler />

    <bean id="messageSource" class="org.springframework.context.support.ResourceBundleMessageSource">
        <property name="basename">
            <value>messages</value>
        </property>
    </bean>

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

</beans>

创建模型类

Spring提供org.springframework.web.multipart.MultipartFile 类代表上传的文件，提供getName(),
getContentType(), getBytes(), getInputStream()等方法。

package com.websystique.springmvc.model;

import org.springframework.web.multipart.MultipartFile;

public class FileBucket {

    MultipartFile file;

    public MultipartFile getFile() {
        return file;
    }

    public void setFile(MultipartFile file) {
        this.file = file;
    }
}

包装类：

package com.websystique.springmvc.model;

import java.util.ArrayList;
import java.util.List;

public class MultiFileBucket {

    List<FileBucket> files = new ArrayList<FileBucket>();

    public MultiFileBucket(){
        files.add(new FileBucket());
        files.add(new FileBucket());
        files.add(new FileBucket());
    }

    public List<FileBucket> getFiles() {
        return files;
    }

    public void setFiles(List<FileBucket> files) {
        this.files = files;
    }
}

创建控制器类

package com.websystique.springmvc.controller;

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import javax.validation.Valid;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.util.FileCopyUtils;
import org.springframework.validation.BindingResult;
import org.springframework.web.bind.WebDataBinder;
import org.springframework.web.bind.annotation.InitBinder;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.multipart.MultipartFile;

import com.websystique.springmvc.model.FileBucket;
import com.websystique.springmvc.model.MultiFileBucket;
import com.websystique.springmvc.util.FileValidator;
import com.websystique.springmvc.util.MultiFileValidator;

@Controller
public class FileUploadController {

    private static String UPLOAD_LOCATION="C:/mytemp/";

    @Autowired
    FileValidator fileValidator;

    @Autowired
    MultiFileValidator multiFileValidator;

    @InitBinder("fileBucket")
    protected void initBinderFileBucket(WebDataBinder binder) {
       binder.setValidator(fileValidator);
    }

    @InitBinder("multiFileBucket")
    protected void initBinderMultiFileBucket(WebDataBinder binder) {
       binder.setValidator(multiFileValidator);
    }

    @RequestMapping(value={"/","/welcome"}, method = RequestMethod.GET)
    public String getHomePage(ModelMap model) {
        return "welcome";
    }

    @RequestMapping(value="/singleUpload", method = RequestMethod.GET)
    public String getSingleUploadPage(ModelMap model) {
        FileBucket fileModel = new FileBucket();
        model.addAttribute("fileBucket", fileModel);
        return "singleFileUploader";
    }

    @RequestMapping(value="/singleUpload", method = RequestMethod.POST)
    public String singleFileUpload(@Valid FileBucket fileBucket, BindingResult result, ModelMap model) throws IOException {

        if (result.hasErrors()) {
            System.out.println("validation errors");
            return "singleFileUploader";
        } else {
            System.out.println("Fetching file");
            MultipartFile multipartFile = fileBucket.getFile();

            //Now do something with file...
            FileCopyUtils.copy(fileBucket.getFile().getBytes(), new File(UPLOAD_LOCATION + fileBucket.getFile().getOriginalFilename()));

            String fileName = multipartFile.getOriginalFilename();
            model.addAttribute("fileName", fileName);
            return "success";
        }
    }

    @RequestMapping(value="/multiUpload", method = RequestMethod.GET)
    public String getMultiUploadPage(ModelMap model) {
        MultiFileBucket filesModel = new MultiFileBucket();
        model.addAttribute("multiFileBucket", filesModel);
        return "multiFileUploader";
    }

    @RequestMapping(value="/multiUpload", method = RequestMethod.POST)
    public String multiFileUpload(@Valid MultiFileBucket multiFileBucket, BindingResult result, ModelMap model) throws IOException {

        if (result.hasErrors()) {
            System.out.println("validation errors in multi upload");
            return "multiFileUploader";
        } else {
            System.out.println("Fetching files");
            List<String> fileNames= new ArrayList<String>();

            //Now do something with file...
            for(FileBucket bucket : multiFileBucket.getFiles()){
                FileCopyUtils.copy(bucket.getFile().getBytes(), new File(UPLOAD_LOCATION + bucket.getFile().getOriginalFilename()));
                fileNames.add(bucket.getFile().getOriginalFilename());
            }

            model.addAttribute("fileNames", fileNames);
            return "multiSuccess";
        }
    }

}

Spring FileCopyUtils 工具类，可以将流从一个地方拷贝到目标文件夹。例子中目标目录是 C:/mytemp 所有文件将传到这里。

创建Validators类

package com.websystique.springmvc.util;

import org.springframework.stereotype.Component;
import org.springframework.validation.Errors;
import org.springframework.validation.Validator;

import com.websystique.springmvc.model.FileBucket;

@Component
public class FileValidator implements Validator {

    public boolean supports(Class<?> clazz) {
        return FileBucket.class.isAssignableFrom(clazz);
    }

    public void validate(Object obj, Errors errors) {
        FileBucket file = (FileBucket) obj;

        if(file.getFile()!=null){
            if (file.getFile().getSize() == 0) {
                errors.rejectValue("file", "missing.file");
            }
        }
    }
}

package com.websystique.springmvc.util;

import org.springframework.stereotype.Component;
import org.springframework.validation.Errors;
import org.springframework.validation.Validator;

import com.websystique.springmvc.model.FileBucket;
import com.websystique.springmvc.model.MultiFileBucket;

@Component
public class MultiFileValidator implements Validator {

    public boolean supports(Class<?> clazz) {
        return MultiFileBucket.class.isAssignableFrom(clazz);
    }

    public void validate(Object obj, Errors errors) {
        MultiFileBucket multiBucket = (MultiFileBucket) obj;

        int index=0;

        for(FileBucket file : multiBucket.getFiles()){
            if(file.getFile()!=null){
                if (file.getFile().getSize() == 0) {
                    errors.rejectValue("files["+index+"].file", "missing.file");
                }
            }
            index++;
        }

    }
}

messages.properties

missing.file= Please select a file.

创建视图

singleFileUploader.jsp

<%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form"%>
<html>

<head>
    <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
    <title>Spring 4 MVC File Upload Example</title>
    <link href="<c:url value='/static/css/bootstrap.css' />"  rel="stylesheet" type="text/css"></link>
    <link href="<c:url value='/static/css/app.css' />" rel="stylesheet" type="text/css"></link>
</head>
<body> 

    <div class="form-container">
        <h1>Spring 4 MVC File Upload Example </h1>
        <form:form method="POST" modelAttribute="fileBucket" enctype="multipart/form-data" class="form-horizontal">

            <div class="row">
                <div class="form-group col-md-12">
                    <label class="col-md-3 control-lable" for="file">Upload a file</label>
                    <div class="col-md-7">
                        <form:input type="file" path="file" id="file" class="form-control input-sm"/>
                        <div class="has-error">
                            <form:errors path="file" class="help-inline"/>
                        </div>
                    </div>
                </div>
            </div>

            <div class="row">
                <div class="form-actions floatRight">
                    <input type="submit" value="Upload" class="btn btn-primary btn-sm">
                </div>
            </div>
        </form:form>
        <a href="<c:url value='/welcome' />">Home</a>
    </div>
</body>
</html>

success.jsp

<%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
    <title>File Upload Success</title>
    <link href="<c:url value='/static/css/bootstrap.css' />" rel="stylesheet"></link>
    <link href="<c:url value='/static/css/app.css' />" rel="stylesheet"></link>
</head>
<body>
    <div class="success">
        File  <strong>${fileName}</strong> uploaded successfully.
        <br/><br/>
        <a href="<c:url value='/welcome' />">Home</a>
    </div>
</body>
</html>

multiFileUploader.jsp

<%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form"%>
<html>

<head>
    <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
    <title>Spring 4 MVC File Multi Upload Example</title>
    <link href="<c:url value='/static/css/bootstrap.css' />"  rel="stylesheet" type="text/css"></link>
    <link href="<c:url value='/static/css/app.css' />" rel="stylesheet" type="text/css"></link>
</head>
<body> 

    <div class="form-container">
        <h1>Spring 4 MVC Multi File Upload Example </h1>
        <form:form method="POST" modelAttribute="multiFileBucket" enctype="multipart/form-data" class="form-horizontal">

            <c:forEach var="v" varStatus="vs" items="${multiFileBucket.files}">
                <form:input type="file" path="files[${vs.index}].file" id="files[${vs.index}].file" class="form-control input-sm"/>
                <div class="has-error">
                    <form:errors path="files[${vs.index}].file" class="help-inline"/>
                </div>
            </c:forEach>
            <br/>
            <div class="row">
                <div class="form-actions floatRight">
                    <input type="submit" value="Upload" class="btn btn-primary btn-sm">
                </div>
            </div>
        </form:form>

        <br/>
        <a href="<c:url value='/welcome' />">Home</a>
    </div>
</body>
</html>

multiSuccess.jsp

<%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
    <title>File Upload Success</title>
    <link href="<c:url value='/static/css/bootstrap.css' />" rel="stylesheet"></link>
    <link href="<c:url value='/static/css/app.css' />" rel="stylesheet"></link>
</head>
<body>
    <div class="success">
            <c:forEach var="fileName" items="${fileNames}">
                File  <strong>${fileName}</strong> uploaded successfully<br/>
            </c:forEach>
            <br/>
        <a href="<c:url value='/welcome' />">Home</a>
    </div>
</body>
</html>

welcome.jsp

<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>

<head>
    <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
    <title>Spring 4 MVC File Upload Example</title>
    <link href="<c:url value='/static/css/bootstrap.css' />"  rel="stylesheet"></link>
    <link href="<c:url value='/static/css/app.css' />" rel="stylesheet"></link>
</head>
<body>
    <div class="form-container">
        <h1>Welcome to FileUploader Example</h1>

        Click on below links to see FileUpload in action.<br/><br/>

        <a href="<c:url value='/singleUpload' />">Single File Upload</a>  OR  <a href="<c:url value='multiUpload' />">Multi File Upload</a>
    </div>
</body>
</html>

创建初始化类

package com.websystique.springmvc.configuration;

import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;

public class HelloWorldInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {

    @Override
    protected Class<?>[] getRootConfigClasses() {
        return new Class[] { HelloWorldConfiguration.class };
    }

    @Override
    protected Class<?>[] getServletConfigClasses() {
        return null;
    }

    @Override
    protected String[] getServletMappings() {
        return new String[] { "/" };
    }

 }