Spring mvc上传图片-优快云博客

本文链接：https://blog.youkuaiyun.com/chenxu_joy/article/details/84464102

本文介绍如何利用Spring MVC框架配合commons-fileupload组件实现文件上传功能。通过具体示例展示了前端表单设置、文件类型验证、后端处理逻辑及配置等关键步骤。

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[size=medium]首先引入commons-fileupload-1.2.1.jar和commons-io-1.4.jar架包[/size]

jsp代码：
form表单必须加上[color=red]enctype="multipart/form-data"[/color]


<script type="text/javascript">
		function addNewsImg(){
			var img = document.getElementById("img").value;
			if(img == null || img == ""){
				alert("上传图片不能为空！");
				return;
			}else{
				var  length = img.lastIndexOf(".");
	            var postfix = img.substring(length+1,img.length);
	            if(postfix!="jpg"&&postfix!="gif"){
	                alert("上传的文件必须是jpg或gif结尾，请重新选择！");
	                document.getElementById("img").value="";
	                return ;
	            }else{
	            	document.getElementById("addForm").action="${basePath}/admin/addNewsImg.html";
	            	document.getElementById("addForm").submit();
	            }
			}
		}

	</script>


<form action="" id="addForm" method="post" enctype="multipart/form-data">
    	<center>
    	<table>
    		<tr>
    			<td><span style="color: red">*</span>图片：</td>
    			<td>
    				<input type="file" name="img" id="img" size="40"/>
    			</td>
    		</tr>
    		<tr>
    			<td colspan="2">
    				<center>
    				<input type="button" name="OK" onclick="addNewsImg();" value="添加"/>
					<input type="reset" name="CANNEL" value="重置"/>
					</center>
    			</td>
    		</tr>
    	</table>
    	</center>
    </form>

java代码：


//添加新闻图片
	@RequestMapping("/admin/addNewsImg.html")
	public String addNewsImages(HttpServletRequest request,HttpServletResponse response,ModelMap model) throws IOException{
		String uploadImageFilePath = request.getSession().getServletContext().getRealPath("/")+"upload/newsImg/";

		MultipartHttpServletRequest multipartRequest = (MultipartHttpServletRequest) request;
		CommonsMultipartFile img = (CommonsMultipartFile) multipartRequest.getFile("img");

		byte[] filebyte = img.getBytes();
		if (filebyte.length > 0) {
			File dirPath = new File(uploadImageFilePath);
			if (!dirPath.exists()) {
				dirPath.mkdirs();
			}
			Calendar CD = Calendar.getInstance();
			String lastname = img.getOriginalFilename().substring(img.getOriginalFilename().lastIndexOf('.'));
			String filename = System.currentTimeMillis() + CD.get(Calendar.MILLISECOND) + "1" + lastname;
			File uploadedFile = new File(uploadImageFilePath + filename);
			FileCopyUtils.copy(filebyte, uploadedFile);

			NewsImgEntity entity = new NewsImgEntity();
			entity.setImg("/upload/newsImg/" + filename);
			entity.setCreateTime(new Date());
			entity.setUpdateTime(new Date());
			entity.setIsAvailable(1);
			String a = imgService.saveNewsImg(entity);
			if(a != null && a.trim().length()>0){
				model.addAttribute("message", "success");
				return "admin/imgMessage";
			}else{
				model.addAttribute("message", "error");
				return "admin/imgMessage";
			}
		}else{
			model.addAttribute("message", "error");
			return "admin/imgMessage";
		}
	}

XML代码：


<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
	    <property name="maxUploadSize">
	        <value>104857600</value>
	    </property>
	    <property name="maxInMemorySize">
	        <value>4096</value>
	    </property>
	</bean>