Sping支持文件的上传和下载

spring-xml文件配置

<!-- 文件上传组件 -->
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver" >
</bean>

表单页面

//表单必须用post

<form action="upLoad" method="post" enctype="multipart/form-data">
文件:<input type="file" name="upLoadFile" ><br/>
</br>
<input type="submit" value="提交"/>
</form>

控制器处理

@Controller
@RequestMapping("/xw")
public class XwController {
@RequestMapping("/upLoad")
public String upLoad(MultipartFile upLoadFile,HttpSession session) throws IOException{

//uploadFile和表单中的file的name一致
if(upLoadFile.getSize()<=0){
session.setAttribute("message", "未选择文件！");
return "false";
}else if(upLoadFile.getSize()>1024*2*1024){
session.setAttribute("message", "文件过大！");
return "false";
}else{
//获取文件名作为保存到服务器的文件名称
String fileName=upLoadFile.getOriginalFilename();
//将上传的文件转成Byte数组
byte [] bytes = upLoadFile.getBytes();
//前半部分路径，目录
String leftPath=session.getServletContext().getRealPath("/WEB-INF/files");
File file=new File(leftPath);
if(!file.exists()){
file.mkdirs();
}
File child=new File(file, fileName);
child.createNewFile();
FileOutputStream fos=new FileOutputStream(child);
fos.write(bytes);
session.setAttribute("message", "上传成功！");
return "success";
}
}
@RequestMapping("/index")
public String index(){
return "index";
}
}