利用spring的MultipartFile实现文件上传
主要依赖jar包
spring-web-3.0.6.RELEASE.jar 用到 (org.springframework.web.multipart.MultipartFile)
commons-fileupload-1.3.1.jar
commons-logging-1.0.4.jar
前台
<!DOCTYPE html> <html lang="en"> <head> <meta charset="utf-8"> <title>上传</title> <style type="text/css"> </style> </head> <body> <form enctype="multipart/form-data" action="/kingtool/file/upload.do" method="POST"> file: <input id="file" type="file" name="file" /> <input type="submit" value="提交" /> </form> </body> </html>
后台
package com.bobo.code.web.controller; import java.io.File; import java.io.IOException; import java.math.BigDecimal; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; import org.springframework.stereotype.Controller; import org.springframework.ui.ModelMap; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.bind.annotation.RequestParam; import org.springframework.web.multipart.MultipartFile; @Controller @RequestMapping({ "file/*" }) public class LoginController { /** * 承保文件上传 * * @param session */ @RequestMapping(value = "upload.do", method = { RequestMethod.POST, RequestMethod.GET }) public void fileUpload(HttpSession session, ModelMap modelMap, HttpServletResponse response, HttpServletRequest request, @RequestParam("file") MultipartFile file) throws Exception, IOException { String ret = ""; request.setCharacterEncoding("UTF-8");// 编码格式处理 // 获取文件名 String fileName = file.getOriginalFilename(); System.out.println("fileName:------------------------------------------------------" + fileName); // 获取文件大小kb BigDecimal fileSize = new BigDecimal(file.getSize()).divide(new BigDecimal(1024), 2, BigDecimal.ROUND_HALF_UP); String startFileName = fileName.substring(0, fileName.indexOf(".")); String endFileName = fileName.substring(fileName.lastIndexOf(".")); // 新文件名称 String newFileName = startFileName + "_" + Math.random() + endFileName; // 文件保存路径 String parentPath = request.getSession().getServletContext().getRealPath("/") + "upload/"; String filePath = parentPath + newFileName; System.out.println("filePath:-----------------------------------------------------------" + filePath); System.out.println("System.setProperty('sun.jnu.encoding') --------" + System.getProperty("sun.jnu.encoding")); System.setProperty("sun.jnu.encoding", "utf-8"); System.out.println("System.setProperty('sun.jnu.encoding') --------" + System.getProperty("sun.jnu.encoding")); File newFile = new File(parentPath); if (!newFile.exists()) {// 判断文件夹是否创建，没有创建则创建新文件夹 newFile.mkdirs(); } boolean uploadFile = true; // 比较上传文件大小是否超过10M if (fileSize.compareTo(new BigDecimal(1024 * 10)) > 0) { uploadFile = false; ret = "上传文件的大小不能超过10Mb,请重新选择!"; } if (uploadFile) { try { file.transferTo(new File(filePath));// 转存文件 ret = "上传成功!"; } catch (Exception e) { ret = "上传失败!"; } } try { response.setContentType("text/html;charset=UTF-8"); response.getWriter().write(ret); response.getWriter().flush(); } catch (IOException e) { e.printStackTrace(); } } }
spring bean配置
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"> <!-- maxUploadSize:文件上传的最大值以byte为单位 --> <property name="maxUploadSize" value="1024000"></property> <property name="defaultEncoding" value="GBK"></property> </bean>
如果不配置,可能报如下错org.springframework.web.bind.MissingServletRequestParameterException: Required MultipartFile parameter 'file' is not present
遇见异常
异常 Required request part 'file' is not present
我遇到的问题和网上的完全不一样, 在springboot中为了能对所有获取到的request提前打印请求报文,在filter又做了一层request wraper包装处理 , 导致file 参数丢失了.
@Component @WebFilter(filterName = "httpServletRequestFilter", urlPatterns = { "/controller/**", "/j_spring_security_check**"}) @Order(-12345) public class HttpServletRequestFilter implements Filter { private static final Logger logger = LoggerFactory.getLogger(HttpServletRequestFilter.class); @Override public void init(FilterConfig filterConfig) throws ServletException { } @Override public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException { BufferedServletRequestWrapper requestWrapper = null; if (servletRequest instanceof HttpServletRequest) { requestWrapper = new BufferedServletRequestWrapper((HttpServletRequest) servletRequest); HttpSession session = requestWrapper.getSession(); try { logger.info("----------------------------------------------------------------------"); logger.info("HttpServletRequestFilter"); logger.info("url: " + requestWrapper.getRequestURL() + "?" + requestWrapper.getQueryString()); logger.info("sessionId: " + session.getId()); logger.info("servletPath: " + requestWrapper.getServletPath()); logger.info("requestMethod: " + requestWrapper.getMethod()); logger.info("requestHeader: " + HttpServletRequestFilter.getStringFromHead((HttpServletRequest) servletRequest)); logger.info("body: " + HttpServletRequestFilter.getStringFromStream(requestWrapper)); logger.info("---------------------------------------------------------------------- "); } catch (Exception e) { e.printStackTrace(); } filterChain.doFilter(requestWrapper, servletResponse); } else { filterChain.doFilter(servletRequest, servletResponse); } } }
ajax文件上传
如果用ajax文件上传时注意contentType:false 一定要为false, 不要自传多情传什么 contentType: "multipart/form-data;charset=utf-8;boundary=" + Math.random(),
不然springboot的后台controller死活不成功, 永远报错为: MissingServletRequestPartException: Required request part 'file' is not present
<script type="text/javascript">
function upload() {
$("#result").html("upload");
var formData = new FormData();
formData.append("file", $("#file")[0].files[0]);
$.ajax({
url: 'http://localhost/controller/finance/asset/manager/upload',
type: 'post',
data: formData,
contentType: false,
processData: false,
success: function (res) {
$("#result").html(res);
}
});
}
</script>
本小节参考: 解决springboot MultipartFile文件上传遇到的问题==>http://www.manongjc.com/article/4682.html
参考
MultipartFile+ajax图片上传==>https://blog.csdn.net/q394503873/article/details/80737323