微信小程序上传文件Java后台实现

微信小程序上传文件

开发环境：微信开发者工具+eclipse+Tomcat+Mysql

1、过程描述

Mysql中存放的是文档的记录（如文档名、存放的地址等），而不是文档中实际的内容。
文档实际存放在本地磁盘的某个文件夹中
微信开发者工具提供接口，访问eclipse中的Java项目地址，在对应的Java项目中将读到的内容写入磁盘。

2、代码

前台

.wxml

<form bindsubmit="submit"> <view> <input placeholder='请输入文件名,如:张三-论文' name="fileName" /> <view class='button'> <button type='primary' form-type='submit'>确定</button> </view> </view> <view class="br"></view> <view class="weui-uploader__input-box"> <view class="weui-uploader__input" bindtap="upload"></view> </view> </form>

.js

var account; var fileName; Page({ data: { files: [] }, submit:function(e){ var objData = e.detail.value; fileName=objData.fileName; if (fileName==''){ wx.showToast({ title: '请输入文件名', duration: 2000, }) } }, upload: function(e) { if(fileName==''){ wx.showToast({ title: '请输入文件名', }) } if (fileName == ''||fileName == undefined) { wx.showToast({ title: '请确定', }) } else{ var account = wx.getStorageSync('account'); var that = this; wx.chooseMessageFile({ count: 10, type: 'file', success(res) { wx.uploadFile({ url: 'http://192.168.x.xxx:8080/GraduateDesign/StuUploadPaper', filePath: res.tempFiles[0].path, name: 'file', header: { 'content-type': 'multipart/form-data' }, formData:{ fileName:fileName, account:account }, success(res) { if(res.data==1) wx.showToast({ title: '上传成功', }) else{ wx.showToast({ title: '文件已存在', }) } } }) } }) } } })

.json

{ "navigationBarTitleText": "提交论文" }

.wxss

input{ border: 1px solid #ccc; height: 40px; margin-left: 10px; margin-right: 10px; } .button{ margin-top: 10px; margin-left: 10px; } .weui-uploader__input-box{ margin-bottom: 40px; margin-left: 100px; width:120px; height: 120px; } .br{ width: 20px; height: 20px; }

后台

（只贴了关键部分）

package GraduateDesign.servlet; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.io.Writer; import java.text.SimpleDateFormat; import java.util.Date; import java.util.List; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.commons.fileupload.FileItem; import org.apache.commons.fileupload.FileUploadException; import org.apache.commons.fileupload.disk.DiskFileItemFactory; import org.apache.commons.fileupload.servlet.ServletFileUpload; import GraduateDesign.domain.StuFile; import GraduateDesign.service.StuFileService; public class StuUploadPaper extends HttpServlet { private static final long serialVersionUID = 1L; public StuUploadPaper() { super(); // TODO Auto-generated constructor stub } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub request.setCharacterEncoding("utf-8"); response.setContentType("text/html;charset=utf-8"); response.setHeader("Access-Control-Allow-Origin", "*"); response.setHeader("Access-Control-Allow-Methods", "GET,POST"); String fname=null; //前台传过来的文件名（不带后缀） String account=null; //教师工号 String value=null; //前台传的formdata中的值，有两个：file、account，要遍历取出 String fileName=null; //最终的文件名称(带后缀) String destPath=null; //上传的文件的完整地址 String path ="D:/eclipse-workspace/GraduateDesign/WebContent/WEB-INF/paper"; //这是我在磁盘上存放文件的地址 File dir = new File(path); /*如果指定目录不存在就创建*/ if (!dir.exists()) { dir.mkdir(); } DiskFileItemFactory factory=new DiskFileItemFactory(); factory.setRepository(dir); //设置缓存的大小，当上传文件的容量超过该缓存时，直接放到暂时存储室 factory.setSizeThreshold(1024 * 1024); //高水平的API文件上传处理 ServletFileUpload upload=new ServletFileUpload(factory); upload.setHeaderEncoding("utf-8");//解决前台传过来的值乱码问题 try { List<FileItem> list=upload.parseRequest(request); FileItem file=null; for(FileItem item : list){ if (item.isFormField()) { //获取用户具体输入的字符串,分别取出文件名fname和学生学号account value = item.getString("utf-8"); if(fname==null){ fname=value; continue; } if(account==null){ account=value; } } else { file = item; } } fileName = account+"-"+fname + ".doc"; destPath = path + "/" + fileName; //真正写到磁盘上 //System.out.println(destPath); File f = new File(destPath); OutputStream out = new FileOutputStream(f); InputStream in = file.getInputStream(); int length = 0; byte[] buf = new byte[1024]; // in.read(buf) 每次读到的数据存放在buf 数组中 while ((length = in.read(buf)) != -1) { //在buf数组中取出数据写到（输出流）磁盘上 out.write(buf, 0, length); } in.close(); out.close(); } catch (FileUploadException e) { // TODO Auto-generated catch block e.printStackTrace(); } /*更新数据库中记录*/ Date date=new Date(); SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); String time=df.format(date); StuFile sf=new StuFile(); sf.setFileName(fileName); sf.setFileUrl(destPath); sf.setSno(account); sf.setDate(time); StuFileService sfs=new StuFileService(); boolean b=sfs.upload(sf); /*向前台返回是否成功标志位*/ String flag; if(b==true) flag="1"; else flag="0"; Writer out = response.getWriter(); out.write(flag); out.flush(); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } }

3、运行结果

数据库中记录
本地磁盘记录

附：
两个jar包（io包、fileupload包），百度网盘https://pan.baidu.com/s/1-xdFZSsCJo7Ai3f
提取码:8mvg