Spring MVC 4使用Servlet 3 MultiPartConfigElement实现文件上传（带源码）
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原文地址：http://websystique.com/springmvc/spring-mvc-4-file-upload-example-using-multipartconfigelement/
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本文在Servlet 3 环境下使用实现了StandardServletMultipartResolver 接口的SpringMultipartResolver类，来实现单个或者多文件上传。
Spring 提供内置的multipart 来支持web应用的文件上传。
概览
前面的文章讲述了用 CommonsMultipartResolver实现文件上传. 在Servlet 3.0 环境下甚至都很好用.本文也将实现同样的上传效果, 但在Servlet 3.0 指定用javax.servlet.MultipartConfigElement
在Servlet 3.0作用要在 Spring 里激活Multipart。需要下面的步骤：
1. 在 Spring配置中添加StandardServletMultipartResolver Bean.它是基于ased on the Servlet 3.0 javax.servlet.http.Part API的MultipartResolver接口的标准实现类,
2. Servlet 3.0环境下启用MultiParsing . 要做到这样,你有很多选择.
- 选项A. Servlet中设置
javax.servlet.MultipartConfigElement. MultipartConfigElement是javax.servlet.annotation.MultipartConfig注解的表示(和选项 c中类似). 本文中将用此种方法。 - 选项 B. 如果是基于XML的配置, 在 web.xml中配置multipart-config 节点, 如下:
<servlet>
<servlet-name>SpringDispatcher</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<multipart-config>
<location>/tmp</location>
<max-file-size>5242880</max-file-size><!--5MB-->
<max-request-size>20971520</max-request-size><!--20MB-->
<file-size-threshold>0</file-size-threshold>
</multipart-config>
</servlet>
选项C. 你可以通过
javax.servlet.annotation.MultipartConfig
注解来自定义Servlet，如下:
@WebServlet(name = "fileUploadServlet", urlPatterns = {"/upload"})
@MultipartConfig(location=/tmp,
fileSizeThreshold=0,
maxFileSize=5242880, // 5 MB
maxRequestSize=20971520) // 20 MB
public class FileUploadServlet extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//handle file upload
}
完整例子
使用的技术和软件
- Spring 4.2.0.RELEASE
- 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
pom.xml里声明依赖
<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>Spring4MVCFileUploadMultipartResolverExample</artifactId>
<packaging>war</packaging>
<version>1.0.0</version>
<name>Spring4MVCFileUploadMultipartConfigElementExample 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>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>Spring4MVCFileUploadMultipartConfigElementExample</warName>
<failOnMissingWebXml>false</failOnMissingWebXml>
</configuration>
</plugin>
</plugins>
</pluginManagement>
<finalName>Spring4MVCFileUploadMultipartConfigElementExample</finalName>
</build>
</project>
MultiPartConfigElement注册
注册MultiPartConfigElement提供定制最大文件大小、请求大小等。在上传文件才做时以及存在本地临时文件的位置和入口。package com.websystique.springmvc.configuration;
import javax.servlet.MultipartConfigElement;
import javax.servlet.ServletRegistration;
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[] { "/" };
}
@Override
protected void customizeRegistration(ServletRegistration.Dynamic registration) {
registration.setMultipartConfig(getMultipartConfigElement());
}
private MultipartConfigElement getMultipartConfigElement() {
MultipartConfigElement multipartConfigElement = new MultipartConfigElement( LOCATION, MAX_FILE_SIZE, MAX_REQUEST_SIZE, FILE_SIZE_THRESHOLD);
return multipartConfigElement;
}
private static final String LOCATION = "C:/temp/"; // Temporary location where files will be stored
private static final long MAX_FILE_SIZE = 5242880; // 5MB : Max file size.
// Beyond that size spring will throw exception.
private static final long MAX_REQUEST_SIZE = 20971520; // 20MB : Total request size containing Multi part.
private static final int FILE_SIZE_THRESHOLD = 0; // Size threshold after which files will be written to disk
}
注意，in。我们重写了customizeRegistration 方法将MultiPartConfigElement注册到DispatcherServlet
创建配置
创建
StandardServletMultipartResolver
Bean。
它是基于
Servlet 3.0 javax.servlet.http.Part API的MultipartResolver 接口的实现类。
package com.websystique.springmvc.configuration;
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.support.StandardServletMultipartResolver;
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 StandardServletMultipartResolver resolver() {
return new StandardServletMultipartResolver();
}
@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/");
}
}
对应的XML配置：
<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.support.StandardServletMultipartResolver"/>
<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Model（模型）类
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;
}
}
此类最多可以处理3个文件上传
创建控制器
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";
}
}
}
将宝存在 C:/mytemp文件夹。
创建Validators （验证器）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>
<%@ 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>
<%@ 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>
构建发布和运行
在tomcat里发布运行
浏览器输入：
http://localhost:8080/Spring4MVCFileUploadMultipartConfigElementExample/ 回车
选择单文件上传链接
如果没有选择文件直接点上传会有验证提示
选择一个文件
点击上传
可以去C:/mytemp 文件夹查看上传的文件
选择多文件上传
如果不选择 直接点击上传
选择文件
点击：上传
检查保存的文件夹C:/mytemp
项目文件下载：http://websystique.com/?smd_process_download=1&download_id=1759