SpringMVC文件上傳功能實例解析

更新時間：2017年03月09日 10:30:58 作者：MrSaber

這篇文章主要介紹了SpringMVC文件上傳功能實例解析,非常不錯，具有參考借鑒價值，需要的朋友可以參考下

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(nèi)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:

<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。

<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(jīng)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：

package domain;
import org.springframework.web.multipart.MultipartFile;
import java.io.Serializable;
import java.util.List;
public class Product implements Serializable {
  //實現(xiàn)了這個接口，可以安全的將數(shù)據(jù)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(huán)境變量

編寫視圖

代碼:

<%@ 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。

<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

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;
@Controller
public 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(shù)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(xiàn)Apache Commons FileUpload 1.2或以上。
　　提供“maxuploadsize”、“maxinmemorysize”和“defaultencoding”設置bean的屬性（繼承commonsfileuploadsupport）

<?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(tài)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(tài)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(jīng)過dispatcher的話,就會發(fā)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(nèi)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(chǔ)上添加了配置項：multipart-config

<?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(nèi)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

MultipartResolver接口的標準實現(xiàn),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(guān)注的是HTML5 input元素的change事件，當input元素的值發(fā)生改變時，他就會被觸發(fā)。其次，我們還關(guān)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(xù)地觸發(fā)progress事件，直到上傳進度完成或者取消。通過輕松監(jiān)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

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

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;
@Controller
public 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(jīng)寫人本地文件:"+file1.getName());
    } catch (Exception e) {
      e.printStackTrace();
    }
  }
}

編寫HTML5頁面

<%--
 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(diào)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(diào)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(fā)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(fā)生改變時，重新獲取并打印現(xiàn)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(zhí)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(diào)試信息。

　　執(zhí)行腳本時，第一件事就是為4個變量分配空間：totalFileLength,totalUploaded,fileCount,filesUploaded;