SpringMVC下Excel文件的上传下载实现

 在实际应用中，经常会遇到上传Excel或者下载Excel的情况，比如导入数据、下载统计数据等等场景。针对这个问题，我写了个基于SpringMVC的简单上传下载示例，其中Excel的处理使用Apache的POI组件。
 
主要依赖的包如下： 

<dependency>
<groupId>commons-io</groupId>
<artifactId>commons-io</artifactId>
<version>2.4</version>
</dependency>
<dependency>
<groupId>commons-fileupload</groupId>
<artifactId>commons-fileupload</artifactId>
<version>1.3.1</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>4.0.0.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>4.0.0.RELEASE</version>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi</artifactId>
<version>3.10.1</version>
</dependency>

 
 
相关处理类：
（一）Controller类 

package com.research.spring.controller;

import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.servlet.ModelAndView;

import com.research.spring.model.UserInfo;
import com.research.spring.view.ExcelView;

@Controller
@RequestMapping("/file")
public class FileController {

/**
* Excel文件上传处理
* @param file
* @return
*/
@RequestMapping("/upload")
public ModelAndView uploadExcel(@RequestParam("file") MultipartFile file){
List<UserInfo> list = new ArrayList<UserInfo>();
//这里只处理文件名包括“用户”的文件，模板使用下载模板
if( file.getOriginalFilename().contains("用户") ){
try {
Workbook wb = new HSSFWorkbook(file.getInputStream());
Sheet sheet = wb.getSheetAt(0);
for( int i = 1; i <= sheet.getLastRowNum(); i++ ){
Row row = sheet.getRow(i);
UserInfo info = new UserInfo();
info.setUserName(row.getCell(0).getStringCellValue());
info.setPassword(row.getCell(1).getStringCellValue());
list.add(info);
}
} catch (IOException e) {
e.printStackTrace();
}
}
ModelAndView mav = new ModelAndView("content");
mav.addObject("content",list.toString());
return mav;
}

/**
* Excel文件下载处理
*/
@RequestMapping("/download")
public ModelAndView downloanExcel(){
List<UserInfo> list = new ArrayList<UserInfo>();
UserInfo userInfo = new UserInfo();
userInfo.setPassword("0000");
userInfo.setUserName("sdfas");
list.add(userInfo);
list.add(userInfo);
list.add(userInfo);
list.add(userInfo);
Map<String,List<UserInfo>> map = new HashMap<String, List<UserInfo>>();
map.put("infoList", list);
ExcelView ve = new ExcelView();
return new ModelAndView(ve,map);
}
} 

 
 （二）实体类 

package com.research.spring.model;

public class UserInfo {

private String userName;

private String password;

public String getUserName() {
return userName;
}

public void setUserName(String userName) {
this.userName = userName;
}

public String getPassword() {
return password;
}

public void setPassword(String password) {
this.password = password;
}

@Override
public String toString() {
return "UserInfo [userName=" + userName + ", password=" + password
+ "]";
}
}

 
（三）View类
这个类在下载时用到，在Spring渲染页面时使用自定义的View类进行Excel的相关处理。 

package com.research.spring.view;

import java.io.OutputStream;
import java.net.URLEncoder;
import java.util.List;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.springframework.web.servlet.view.document.AbstractExcelView;

import com.research.spring.model.UserInfo;

/**
* 下载Excel视图
*
* @author wdmcygah
*
*/
public class ExcelView extends AbstractExcelView {

@Override
protected void buildExcelDocument(Map<String, Object> model,
HSSFWorkbook workbook, HttpServletRequest request,
HttpServletResponse response) throws Exception {
@SuppressWarnings("unchecked")
List<UserInfo> list = (List<UserInfo>) model.get("infoList");
if (list != null && list.size() != 0) {
int len = list.size();
Sheet sheet = workbook.createSheet();
// 第一行文字说明
Row row = sheet.createRow(0);
Cell cell = row.createCell(0, Cell.CELL_TYPE_STRING);
cell.setCellValue("用户名");
cell = row.createCell(1, Cell.CELL_TYPE_STRING);
cell.setCellValue("密码");

//下面是具体内容
for (int i = 0; i < len; i++) {
row = sheet.createRow(i + 1);
cell = row.createCell(0, Cell.CELL_TYPE_STRING);
cell.setCellValue(list.get(i).getUserName());
cell = row.createCell(1, Cell.CELL_TYPE_STRING);
cell.setCellValue(list.get(i).getPassword());
}
}

response.setContentType("application/vnd.ms-excel");
response.setCharacterEncoding("utf-8");
//这里对文件名进行编码，保证下载时汉字显示正常
String fileName = URLEncoder.encode("用户.xls", "utf-8");
//Content-disposition属性设置成以附件方式进行下载
response.setHeader("Content-disposition", "attachment;filename="
+ fileName);
OutputStream os = response.getOutputStream();
workbook.write(os);
os.flush();
os.close();
}
}

 
（四）主要配置文件
上传文件时需要在配置文件中配置MultipartResolver类，配置后Spring会自动将文件传成MultipartFile对象，然后就可以进行相应的处理。示例看Controller类。 

<?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"
xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:util="http://www.springframework.org/schema/util"
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 http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.0.xsd"> 
<context:component-scan base-package="com.research" />

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

<!-- 上传文件解析器配置 -->
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<property name="defaultEncoding" value="UTF-8"></property>
<!-- 上传文件的大小限制 ，单位是字节-->
<property name="maxUploadSize" value="5242880000000"></property>
<!-- 上传文件的临时路径，上传完成后会自动删除 -->
<property name="uploadTempDir" value="upload/temp"></property>
</bean>
</beans>

 
（五）测试页面

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
</head>
<body>
<h3>测试下载Excel功能</h3>
<form action="file/download.htm" enctype="multipart/form-data" method="post">
<input type="submit" value="下载Excel"></input>
</form>

<h3>测试上传Excel功能</h3>
<form action="file/upload.htm" enctype="multipart/form-data" method="post">
<input type="file" name="file"></input>
<input type="submit" value="上传Excel"></input>
</form>
</body>
</html>

 
如果想看完整源码，可以到我的Github仓库查看：https://github.com/wdmcygah/research-spring。 其中，上传文件只处理符合下载模板的文件。若要处理其它文件需要自实现。代码测试通过无误。