<commons-fileupload.version>1.3.3</commons-fileupload.version>
<dependency>
<groupId>commons-fileupload</groupId>
<artifactId>commons-fileupload</artifactId>
<version>${commons-fileupload.version}</version>
</dependency>
在spring-mvc.xml文件中添加文件上传解析器。
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<!-- 必须和用户JSP 的pageEncoding属性一致，以便正确解析表单的内容 -->
<property name="defaultEncoding" value="UTF-8"></property>
<!-- 文件最大大小(字节) 1024*1024*50=50M-->
<property name="maxUploadSize" value="52428800"></property>
<!--resolveLazily属性启用是为了推迟文件解析，以便捕获文件大小异常-->
<property name="resolveLazily" value="true"/>
</bean>
这段代码是一个Spring框架的配置，用于处理文件上传功能。它定义了一个名为
multipartResolver的Bean，使用org.springframework.web.multipart.commons.CommonsMultipartResolver类来处理文件上传。其中设置了默认的编码方式为UTF-8，文件的最大大小为50MB，并启用了懒解析模式。这段代码的作用是配置文件上传的相关参数。
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<base href="${pageContext.request.contextPath }">
<title>文件上传</title>
</head>
<body>
<form action="/file/upload" method="post" enctype="multipart/form-data">
<label>编号：</label><input type="text" name="id" readonly="readonly" value="${param.id}"/><br/>
<label>图片：</label><input type="file" name="imgFile"/><br/>
<input type="submit" value="上传图片"/>
</form>
</body>
</html>
（1） 设计表
(2) 配置generatorConfig.xml，并生成代码
<table schema="" tableName="file_upload" domainObjectName="UploadFile"
enableCountByExample="false" enableDeleteByExample="false"
enableSelectByExample="false" enableUpdateByExample="false">
</table>
（3） 创建业务层
（4） 配置resource.properties
#本地路径
dir=D:/upload/
#服务器路径
server=/upload/
(5) 配置文件读取工具类
package com.xqx.utils;
import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;
public class PropertiesUtil {
public static String getValue(String key) throws IOException {
Properties p = new Properties();
InputStream in = PropertiesUtil.class.getResourceAsStream("/resource.properties");
p.load(in);
return p.getProperty(key);
}
}
（6） 配置项目与映射地址
(7) 编写控制器
package com.xqx.web;
import com.xqx.biz.UploadFileBiz;
import com.xqx.model.UploadFile;
import com.xqx.utils.PageBean;
import com.xqx.utils.PropertiesUtil;
import org.apache.commons.io.FileUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.multipart.MultipartFile;
import javax.servlet.http.HttpServletRequest;
import java.io.File;
import java.io.IOException;
import java.util.List;
@Controller
@RequestMapping("/file")
public class UploadFileController {
@Autowired
private UploadFileBiz UploadFileBiz;
/*新增方法*/
@RequestMapping("/add")
public String save(UploadFile UploadFile, HttpServletRequest request) {
UploadFileBiz.insertSelective(UploadFile);
return "redirect:list";
}
/*删除方法*/
@RequestMapping("/del/{id}")
public String del(@PathVariable("id") Integer id) {
UploadFileBiz.deleteByPrimaryKey(id);
return "redirect:/file/list";
}
/*修改方法*/
@RequestMapping("/edit")
public String edit(UploadFile UploadFile, HttpServletRequest request) {
UploadFileBiz.updateByPrimaryKeySelective(UploadFile);
return "redirect:list";
}
/*查询方法*/
@RequestMapping("/list")
public String list(UploadFile UploadFile, HttpServletRequest request) {
PageBean pageBean = new PageBean();
pageBean.setRequest(request);
List<UploadFile> UploadFiles = UploadFileBiz.listPager(UploadFile, pageBean);
// ModelAndView modelAndView = new ModelAndView();
// modelAndView.addObject("UploadFiles", UploadFiles);
// modelAndView.addObject("pageBean", pageBean);
// modelAndView.setViewName("UploadFile/list");
request.setAttribute("UploadFiles", UploadFiles);
request.setAttribute("pageBean", pageBean);
return "file/list";
}
/*数据回显*/
@RequestMapping("/preSave")
public String preSave(UploadFile UploadFile, HttpServletRequest request) {
if (UploadFile != null && UploadFile.getId() != null && UploadFile.getId() != 0) {
UploadFile img = UploadFileBiz.selectByPrimaryKey(UploadFile.getId());
request.setAttribute("img", img);
}
return "file/edit";
}
/*图片上传*/
@RequestMapping("upload")
public String upload(UploadFile img,MultipartFile imgFile) throws IOException {
//读取配置文夹本地路径和服务器路径
String dir = PropertiesUtil.getValue("dir");
String server = PropertiesUtil.getValue("server");
//利用MultipartFile类接受前端传递到后台的文件
System.out.println("文件名："+imgFile.getOriginalFilename());
System.out.println("文件类型："+imgFile.getContentType());
//将文件转成流写入到服务器
FileUtils.copyInputStreamToFile(imgFile.getInputStream(),new File(dir+imgFile.getOriginalFilename()));
//通过对象将图片保存到数据库
img.setImg(server+imgFile.getOriginalFilename());
UploadFileBiz.updateByPrimaryKeySelective(img);
return "redirect:list";
}
}
（8） 编写jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ taglib prefix="w" uri="http://jsp.xqx.cn" %>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<link
href="https://cdn.bootcdn.net/ajax/libs/twitter-bootstrap/4.5.0/css/bootstrap.css"
rel="stylesheet">
<script
src="https://cdn.bootcdn.net/ajax/libs/twitter-bootstrap/4.5.0/js/bootstrap.js"></script>
<base href="${pageContext.request.contextPath }">
<title></title>
<style type="text/css">
.page-item input {
padding: 0;
width: 40px;
height: 100%;
text-align: center;
margin: 0 6px;
}
.page-item input, .page-item b {
line-height: 38px;
float: left;
font-weight: 400;
}
.page-item.go-input {
margin: 0 10px;
}
</style>
</head>
<body>
<form class="form-inline"
action="/file/list" method="post">
<div class="form-group mb-2">
<input type="text" class="form-control-plaintext" name="name"
placeholder="请输入用户名称">
</div>
<button type="submit" class="btn btn-primary mb-2">查询</button>
<a class="btn btn-primary mb-2" href="/file/preSave">新增</a>
</form>
<table class="table table-striped">
<thead>
<tr>
<th scope="col">ID</th>
<th scope="col">用户</th>
<th scope="col">图片</th>
</tr>
</thead>
<tbody>
<c:forEach var="i" items="${uploadImgs }">
<tr>
<td>${i.id }</td>
<td>${i.name }</td>
<td>
<img src="${i.img }" style="width: 200px;height: 100px;">
</td>
<td>
<a href="/file/preSave?id=${i.id}">修改</a>
<a href="/file/del/${i.id}">删除</a>
<a href="/page/file/upload?id=${i.id}">图片上传</a>
<a href="/file/download?id=${i.id}">图片下载</a>
</td>
</tr>
</c:forEach>
</tbody>
</table>
<!-- 这一行代码就相当于前面分页需求前端的几十行了 -->
<w:page pageBean="${pageBean }"></w:page>
</body>
</html>
根据传入的文件id查询对应的文件信息，然后根据文件路径读取文件内容，并将文件内容和设置好的HTTP头信息封装成一个ResponseEntity对象，最后返回给客户端进行文件下载。
@RequestMapping("/download")
public ResponseEntity<byte[]> download(UploadImg uploadImg, HttpServletRequest req){
try {
//先根据文件id查询对应图片信息
UploadImg img = this.uploadImgBiz.selectByPrimaryKey(uploadImg.getId());
String diskPath = PropertiesUtil.getValue("dir");
String reqPath = PropertiesUtil.getValue("server");
//上面获取的数据库地址，需要转换才能下载成本地路径
String realPath = img.getImg().replace(reqPath,diskPath);
String fileName = realPath.substring(realPath.lastIndexOf("/")+1);
//下载关键代码
File file=new File(realPath);
HttpHeaders headers = new HttpHeaders();//http头信息
String downloadFileName = new String(fileName.getBytes("UTF-8"),"iso-8859-1");//设置编码
headers.setContentDispositionFormData("attachment", downloadFileName);
headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
//MediaType:互联网媒介类型 contentType：具体请求中的媒体类型信息
return new ResponseEntity<byte[]>(FileUtils.readFileToByteArray(file),headers, HttpStatus.OK);
}catch (Exception e){
e.printStackTrace();
}
return null;
}
//多文件上传
@RequestMapping("/uploads")
public String uploads(HttpServletRequest req, Music music, MultipartFile[] files){
try {
StringBuffer sb = new StringBuffer();
for (MultipartFile cfile : files) {
//思路：
//1) 将上传图片保存到服务器中的指定位置
String dir = PropertiesUtil.getValue("dir");
String server = PropertiesUtil.getValue("server");
String filename = cfile.getOriginalFilename();
FileUtils.copyInputStreamToFile(cfile.getInputStream(),new File(dir+filename));
sb.append(filename).append(",");
}
System.out.println(sb.toString());
} catch (Exception e) {
e.printStackTrace();
}
return "redirect:list";
}
下载
