說明：
文件上傳的途徑
文件上傳主要有兩種方式：
1.使用Apache Commons FileUpload元件。
2.利用Servlet3.0及其更高版本的內置支持。
客戶端編程
1.為了上傳文件，必須將HTML表格的enctype屬性值設為multipart/form-data，像下面這樣:
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<form action="action" enctype="multipart/form-data" method="post"> Select a file<input type="file" name="fieldName"/> <input type="submit" value="Upload"/></form> |
2.在HTML5之前，如果要想上傳多個文件，必須使用多個文件input元素。但是，在HTML5中，通過在input元素中引入多個multiple屬性，使得多個文件的上傳變得更加簡單，下面均可使一個上傳框支持多個文件上傳。
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<input type="file" name="fieldName" multiple/><input type="file" name="fieldName" multiple="multiple"/><input type="file" name="fieldName" multiple=""/> |
MultipartFile接口
在SpringMVC中處理已經上傳的文件十分簡單，上傳到SpringMVC應用程序中的文件會被包在一個MultipartFile對象中，你唯一要做的事情就是用類型為MultipartFile的屬性編寫一個Domain類。就像下面這樣：
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package domain;import org.springframework.web.multipart.MultipartFile;import java.io.Serializable;import java.util.List;public class Product implements Serializable { //實現了這個接口，可以安全的將數據保存到HttpSession中 private long id; private String name; private String description; private String price; //在Domain類中加入MultipartFile類型的屬性，用來保存上傳的文件 private List<MultipartFile> images; public List<MultipartFile> getImages() { return images; } public void setImages(List<MultipartFile> images) { this.images = images; } ......多個get和set方法。 |
MultipartFile接口提供了以下方法：
| Modifier and Type | Method and Description |
|---|---|
| byte[] | getBytes()Return the contents of the file as an array of bytes. |
| String | getContentType()Return the content type of the file. |
| InputStream | getInputStream()Return an InputStream to read the contents of the file from. |
| String | getName()Return the name of the parameter in the multipart form. |
| String | getOriginalFilename()Return the original filename in the client's filesystem. |
| long | getSize()Return the size of the file in bytes. |
| boolean | isEmpty()Return whether the uploaded file is empty, that is, either no file hasbeen chosen in the multipart form or the chosen file has no content. |
| void | transferTo(File dest)Transfer the received file to the given destination file. |
實例：用CommonsFileUpLoad上傳文件
導入Jar包及配置環境變量
編寫視圖
代碼:
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<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form" %><%@ page contentType="text/html;charset=UTF-8" language="java" %><html><head> <title>Add Product Form</title></head><body><form:form action="product_save" method="post" commandName="product" enctype="multipart/form-data"> <fieldset> <legend>Add a Product</legend> <p> <label for="name">ProductName</label> <form:input type="text" id="name" name="name" tabindex="1" path="name"/> </p> <p> <label for="description">ProductDescription</label> <form:input type="text" id="description" name="description" tabindex="2" path="description"/> </p> <p> <label for="price">ProductPrice</label> <form:input type="text" id="price" name="price" tabindex="3" path="price"/> </p> <p> <label for="image">ProductImage</label> <input type="file" name="images[0]"> </p> <p> <input type="reset"> <input type="submit"> </p> </fieldset></form:form></body></html> |
說明：
首先為了上傳文件，必須將HTML表格的enctype屬性值設為multipart/form-data
其次，在HTML5之前，如果要想上傳多個文件，必須要用到多個文件input元素。
但是在HTML5，通過在Input元素中引入過個multiple屬性，使得多個文件上傳變得更加簡單。
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<input type="file" name="fieldName" multiple/><input type="file" name="fieldName" multiple="multiple"/><input type="file" name="fieldName" multiple=""/> |
圖示:
編寫控制器
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package controller;import domain.Product;import Service.ProductService;import org.apache.commons.logging.Log;import org.apache.commons.logging.LogFactory;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Controller;import org.springframework.ui.Model;import org.springframework.validation.BindingResult;import org.springframework.web.bind.annotation.ModelAttribute;import org.springframework.web.bind.annotation.PathVariable;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestMethod;import org.springframework.web.multipart.MultipartFile;import javax.servlet.http.HttpServletRequest;import java.io.File;import java.io.IOException;import java.util.List;@Controllerpublic class ProductController { private static final Log logger=LogFactory.getLog(ProductController.class); @Autowired private ProductService productService; @RequestMapping(value = "/product_input") public String inputProduct(Model model) { logger.info("inputProduct called"); model.addAttribute("product",new Product()); return "ProductForm"; } @RequestMapping(value = "/product_save",method = RequestMethod.POST) public String saveProduct(HttpServletRequest servletRequest, @ModelAttribute Product product, BindingResult bindingResult,Model model) { List<MultipartFile> files= product.getImages(); System.out.println("文件數量是"+files.size()); if(null!=files&&files.size()>0) { for (MultipartFile file:files) { String fileName=file.getOriginalFilename(); //獲得文件名稱 File imagFile = new File(servletRequest.getServletContext().getRealPath("/image"),fileName);try { file.transferTo(imagFile);//用于將文件寫到服務器本地 } catch (IOException e) { e.printStackTrace(); } } } model.addAttribute("product",product); return "ProductDetails"; } @RequestMapping(value = "/product_view/{id}") public String viewProduct(@PathVariable Long id,Model model) { Product product =productService.get(id); model.addAttribute("product",product); return "ProductDetails"; }} |
配置文件
你可以看到我們在SpringMVC的配置文件中配置了一個名為multipartResolver的Bean。
基于servlet的multipartresolver實現Apache Commons FileUpload 1.2或以上。
提供“maxuploadsize”、“maxinmemorysize”和“defaultencoding”設置bean的屬性（繼承commonsfileuploadsupport）
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<?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-3.0.xsd"> <context:component-scan base-package="controller"/> <context:component-scan base-package="Service"/> <!-- <mvc:annotation-driven>元素注冊用于支持基于注解的控制器的請求處理方法的Bean對象。 詳解：https://my.oschina.net/HeliosFly/blog/205343 --> <mvc:annotation-driven></mvc:annotation-driven> <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="prefix" value="/WEB-INF/view/"/> <property name="suffix" value=".jsp"/> </bean> <!--resources 元素指示SpringMVC那些靜態資源需要單獨處理--> <mvc:resources mapping="/image/**" location="/image/"/> <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"> <property name="maxUploadSize" value="2000000"/> </bean></beans> |
說明：
resources 元素指示SpringMVC那些靜態資源需要單獨處理,此處我們要單獨處理的是image,如果不單獨處理而是經過dispatcher的話,就會發生404錯誤.
實例:用Servlet3及其更高版本上傳文件
說明:
有了Servlet3,就不需要Commons FileUpload 和Commons IO元件了.因為在Servlet3中內置了上傳文件的特性.
幸運的是Domain類和Controller類基本不變,我們僅僅需要修改一下配置文件。
配置文件:
修改Web.xml
我們可以看到實在dispatcher的基礎上添加了配置項：multipart-config
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<?xml version="1.0" encoding="UTF-8"?><web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" version="3.1"> <context-param> <param-name>contextConfigLocation</param-name> <param-value>/WEB-INF/applicationContext.xml</param-value> </context-param> <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener> <servlet> <servlet-name>dispatcher</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <load-on-startup>1</load-on-startup> <multipart-config> <max-file-size>20848820</max-file-size> <!--上傳內文件的最大容量--> <max-request-size>418018841</max-request-size> <!--表示多部分HTTP請求允許的最大容量--> <file-size-threshold>1048576</file-size-threshold> <!--超過這個容量將會被寫到磁盤中--> <location>/image/</location> <!--要將已上傳的文件保存到磁盤中的位置--> </multipart-config> </servlet> <servlet-mapping> <servlet-name>dispatcher</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> <!--Spring中文亂碼攔截器--> <filter> <filter-name>setcharacter</filter-name> <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class> <init-param> <param-name>encoding</param-name> <param-value>UTF-8</param-value> </init-param> </filter> <filter-mapping> <filter-name>setcharacter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> </web-app> |
SpringMVC配置文件添加多部分解析器
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MultipartResolver接口的標準實現,基于Servlet 3.0部分API. To be added as "multipartResolver" bean to a Spring DispatcherServlet context, without any extra configuration at the bean level. <bean id="MultipartResolver" class="org.springframework.web.multipart.support.StandardServletMultipartResolver"></bean> |
實例：為多文件上傳添加一個進度條
說明：
我們關注的是HTML5 input元素的change事件，當input元素的值發生改變時，他就會被觸發。其次，我們還關注XMLHttpRequest對象中添加progress事件。XMLHttpRequest自然是AJAX的骨架。當異步使用XMLHttpRequest對象上傳文件的時候就會持續地觸發progress事件，直到上傳進度完成或者取消。通過輕松監聽progress事件，可以輕松地檢測文件上傳操作的進度。
編寫Domain和Controller
1.Domain：UploadFile
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package domain;import org.springframework.web.multipart.MultipartFile;import java.io.Serializable;public class UploadFile implements Serializable { private MultipartFile multipartFile; public MultipartFile getMultipartFile() { return multipartFile; } public void setMultipartFile(MultipartFile multipartFile) { this.multipartFile = multipartFile; }} |
2.Controller:Html5FileUploadController類
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package controller;import domain.UploadFile;import org.apache.commons.logging.Log;import org.apache.commons.logging.LogFactory;import org.springframework.stereotype.Controller;import org.springframework.validation.BindingResult;import org.springframework.web.bind.annotation.ModelAttribute;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.multipart.MultipartFile;import javax.servlet.http.HttpServletRequest;import java.io.File;@Controllerpublic class Html5FileUploadController { private static final Log logger = LogFactory.getLog(Html5FileUploadController.class); @RequestMapping("/html5") public String inputProduct() { return "html5"; } @RequestMapping("/file_upload") public void saveFile(HttpServletRequest servletRequest, @ModelAttribute UploadFile file, BindingResult result) { MultipartFile multipartFile =file.getMultipartFile(); String filename =multipartFile.getOriginalFilename(); try { File file1 = new File(servletRequest.getServletContext().getRealPath("/image"),filename); multipartFile.transferTo(file1); System.out.println("已經寫人本地文件:"+file1.getName()); } catch (Exception e) { e.printStackTrace(); } }} |
編寫HTML5頁面
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<%-- Created by IntelliJ IDEA. User: zy Date: 17-3-8 Time: 下午10:01 To change this template use File | Settings | File Templates.--%><%@ page contentType="text/html;charset=UTF-8" language="java" %><html><head> <title>Title</title></head><body> <script> var totalFileLength,totalUploaded,fileCount,filesUploaded; function debug(s) { //輸出調試信息 var debug = document.getElementById('debug'); if(debug) { debug.innerHTML =debug.innerHTML+'</br>'+s; } } function onUploadComplete(e) { //當一個文件上傳完成，緊接著開始調用下次upLoadNext(); totalUploaded+=document.getElementById('files').files[filesUploaded].size; filesUploaded++; debug('Complete'+filesUploaded+" of "+fileCount); debug('totalUploaded:'+totalUploaded); if(filesUploaded<fileCount) { upLoadNext(); } } function onUploadFailed() { alert("Error uploading file"); } function onUploadProgress(e) {//當進度發生改變時，改變進度條 if(e.lengthComputable) { var percentComplete =parseInt((e.loaded+totalUploaded)*100/totalFileLength); var bar = document.getElementById("bar"); bar.style.width=percentComplete+"%"; bar.innerHTML =percentComplete+"% complete"; } else { debug('unable to compute'); } } function upLoadNext() { //將XMLHttpRequest對象的progress事件添加到onLoadProgress并將load事件和error事件分別綁定到對應方法。 var xhr = new XMLHttpRequest(); var fd =new FormData(); var file =document.getElementById('files').files[filesUploaded]; fd.append("multipartFile",file); xhr.upload.addEventListener("progress",onUploadProgress,false); xhr.addEventListener("load",onUploadComplete,false); xhr.addEventListener("error",onUploadFailed,false); xhr.open("POST","file_upload"); debug('uploading'+file.name); xhr.send(fd); } function onFileSelect(e) { //當選擇的文件發生改變時，重新獲取并打印現在所選的文件信息 var files =e.target.files; var output=[]; fileCount =files.length; totalFileLength =0; for(var i=0;i<fileCount;i++) { var file =files[i]; output.push(file.name,'(',file.size,'bytes',')',file.lastModifiedDate.toLocaleDateString()); output.push("<br/>"); debug('add'+file.size); totalFileLength+=file.size; } document.getElementById('selectedFiles').innerHTML = output.join(''); debug('totalFileLength:'+totalFileLength); } function startUpload() { //當用戶點擊提交以后開始執行 totalUploaded=filesUploaded=0; upLoadNext(); } window.onload=function () { document.getElementById('files').addEventListener('change',onFileSelect,false); document.getElementById('upLoadButton').addEventListener('click',startUpload,false); } </script></body> <h1>Multipart File Uploads with Progress Bar</h1> <div id="bar" style="height:100px;background: #33dd33;width: 0%"> </div><form> <input type="file" id="files" multiple> <br> <output id="selectedFiles"></output> <input id="upLoadButton" type="button" value="Upload"></form><div id="debug" style="height: 100%;border: 2px solid green;overflow: auto"></div></html> |
說明：
progressBar div用于展示上傳進度，debug div用于顯示調試信息。
執行腳本時，第一件事就是為4個變量分配空間：totalFileLength,totalUploaded,fileCount,filesUploaded;
- totalFileLength:主要用于保存上傳文件的總長度。
- totalUploaded:指示目前已經上傳的字節數。
- fileCount：包含了要上傳的文件數量。
- fileUploaded：指示了已經上傳的文件數量。
以上所述是小編給大家介紹的SpringMVC文件上傳功能實例解析，希望對大家有所幫助，如果大家有任何疑問請給我留言，小編會及時回復大家的。在此也非常感謝大家對服務器之家網站的支持！
原文鏈接：http://www.cnblogs.com/MrSaver/p/6524376.html
