SpringMVC文件上传与下载(附工程源码）

电玩女神 2022-05-18 11:10 169阅读 0赞

# 1 实现步骤 #

1.1 引入核心JAR包

SpringMVC实现文件上传，需要再添加两个jar包。一个是文件上传的jar包，一个是其所依赖的IO包。这两个jar包，均在Spring支持库的org.apache.commons中。

![903715-20170110144324025-1051068405.png][]

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## 1.2 书写控制器方法 ##

![903715-20170110174543588-1815307653.png][]

**FileUpController.java 完整**

@Controller
    public class FileUpController {
    
    	@RequestMapping("/")
    	public String index() {
    		return "index";
    	}
    	
    	@RequestMapping(value="upload",method=RequestMethod.POST)
    	public String upload(MultipartFile myFile,Model model,HttpServletRequest request) {
    	
    		//获取上传图片存储目录
    		String path = request.getSession().getServletContext().getRealPath("upload");
    		System.out.println(path);
    		//获取文件名并使用UUID生成新文件名
    		String fileName  = myFile.getOriginalFilename();
    		String newFileName = UUID.randomUUID()+fileName.substring(fileName.lastIndexOf("."));
    		//在指定上传存储目录中创建新文件
    		File targetFile = new File(path,newFileName);
    		//找不到指定上传图片存储目录，就新创建此目录
    		if(!targetFile.exists()) {
    			targetFile.mkdirs();
    		}
    		//将文件写入硬盘
    		try {
    			myFile.transferTo(targetFile);
    		} catch (IllegalStateException | IOException e) {
    			// TODO Auto-generated catch block
    			e.printStackTrace();
    		}
    		//将上传后的文件路径传到view
    		model.addAttribute("fileUrl", request.getContextPath()+"/upload"+newFileName);
    		
    		return "upload";
    	}
    	
    	
    }

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**applicationContext.xml：**

注：必须创建MultipartFile实例。要不出现500错误

![903715-20170110181005541-1920075038.png][]

![903715-20170110174826275-1473630983.png][]

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index.jsp页面：需指定 enctype="multipart/form-data

实现效果：

![903715-20170110175523041-2034384144.png][]

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# 2 没有选择要上传的文件&&限制文件上传类型 #

如果没有选择要上传的文件，可以通过如下判断代码回到错误页，并配置异常类

![903715-20170110175910588-21307520.png][]

<bean class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver">
    
        <property name="defaultErrorView" value="/error.jsp"></property>
    
        </bean>

![903715-20170110181413353-1228447946.png][]

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# 3 多文件上传　 #

![903715-20170110180102181-1885492400.png][]

实现效果：

![903715-20170110180206838-204989870.png][]![903715-20170110180230697-379442517.png][]

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# 4 文件下载 #

![903715-20170110180646619-1351459807.png][]

**DownloadControll.java 完整**

@Controller
    public class DownloadController {
        @RequestMapping(value="download",method=RequestMethod.GET)
        public ResponseEntity<byte[]> download(String filename,HttpServletRequest request)throws Exception {
            //下载文件路径
            String path = request.getServletContext().getRealPath("upload");
            File file = new File(path + "/" + filename);
            //开始设置http请求头
            HttpHeaders headers = new HttpHeaders();  
            //下载显示的文件名，解决中文名称乱码问题  
            String downloadFileName = new String(filename.getBytes("UTF-8"),"ISO-8859-1");
            //通知浏览器以attachment（下载方式）打开文件。
            headers.setContentDispositionFormData("attachment", downloadFileName); 
            //设置mime：application/octet-stream ： 二进制流数据（最常见的文件下载）。
            headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
            return new ResponseEntity<byte[]>(
                           FileUtils.readFileToByteArray(file),    //把一个文件转换成字节数组返回
                           headers,                                                //http请求头
                           HttpStatus.OK                                      //200
                       );  
        }
    }

实现效果：

![903715-20170110181445978-1148627265.png][]![903715-20170110181521197-8266744.png][]

项目源码下载--->>[工程源码下载][Link 1]

[903715-20170110144324025-1051068405.png]: /images/20220518/0fcbf862ec7d44f992abd0b26fbf4f20.png
[903715-20170110174543588-1815307653.png]: /images/20220518/bb4fb952a4fb48dabdfdeec19c07eafa.png
[903715-20170110181005541-1920075038.png]: /images/20220518/869a7ded19614b16bf5e9ed4c5d77f3e.png
[903715-20170110174826275-1473630983.png]: /images/20220518/7e474e85b6314ce18beb68a48047c775.png
[903715-20170110175523041-2034384144.png]: /images/20220518/302bfdc48d074b6789a774815e7d5a38.png
[903715-20170110175910588-21307520.png]: /images/20220518/15e1f6af9e3340deab88000e61bd0dbb.png
[903715-20170110181413353-1228447946.png]: /images/20220518/26b722aaed57497f8192df66584bba63.png
[903715-20170110180102181-1885492400.png]: /images/20220518/280bee5cb71341528954608c537da6b5.png
[903715-20170110180206838-204989870.png]: https://images2015.cnblogs.com/blog/903715/201701/903715-20170110180206838-204989870.png
[903715-20170110180230697-379442517.png]: /images/20220518/f4d3b630d5374c90a6bdd1150581902b.png
[903715-20170110180646619-1351459807.png]: /images/20220518/ae79dbf2fca44655bcecdedab95b1176.png
[903715-20170110181445978-1148627265.png]: https://images2015.cnblogs.com/blog/903715/201701/903715-20170110181445978-1148627265.png
[903715-20170110181521197-8266744.png]: /images/20220518/9ea197cc087c484e8a6d35dd7215162a.png
[Link 1]: https://download.csdn.net/download/sinat_32829963/10580362