Jsp+Servlet实现文件上传下载 删除上传文件(三)

这篇文章主要为大家详细介绍了Jsp+Servlet实现文件上传下载功能的第三部分删除上传文件,具有一定的参考价值,感兴趣的小伙伴们可以参考一下

接着上一篇讲:Jsp+Servlet实现文件上传下载(二)--文件列表展示

本章来实现一下删除已上传文件,同时优化了一下第一章中的代码。

废话少说,上代码得意

1.调整列表页面list.jsp

 <%@ page contentType="text/html;charset=UTF-8" language="java" %><%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>  上传文件列表 

文件列表

文件名文件大小(KB)操作
${acc.fileName}${acc.fileSize}删除

2.新增FileUtils工具类

 package util; import java.io.File; /** * 文件操作工具类 * * @author xusucheng * @create 2017-12-30 **/ public class FileUtils { public static boolean delete(String path){ File file = new File(path); if(!file.isFile()){ System.out.println("删除失败,文件:"+path+"不存在!"); return false; } file.delete(); return true; } } 

3.调整附件实体DAO,新增load方法

 package dao.upload; import entity.upload.EntityAccessory; import util.DBUtil; import java.math.BigDecimal; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.util.ArrayList; import java.util.List; /** * 附件上传DAO * * @author xusucheng * @create 2017-12-29 **/ public class AccessoryDao { public static void add(EntityAccessory entity) { Connection conn = DBUtil.getConnection(); String sql = "insert into tbl_accessory(file_name,file_size,file_ext_name,file_path) values(?,?,?,?)"; try { PreparedStatement ps = conn.prepareStatement(sql); ps.setString(1, entity.getFileName()); ps.setDouble(2, entity.getFileSize()); ps.setString(3, entity.getFile_ext_name()); ps.setString(4, entity.getFilePath()); ps.execute(); //conn.commit(); DBUtil.close(null, ps, conn); } catch (SQLException e) { e.printStackTrace(); } } public static List list() { Connection conn = DBUtil.getConnection(); String sql = "select id,file_name,file_size,file_ext_name,file_path from tbl_accessory"; List accessoryList = new ArrayList<>(); try { PreparedStatement ps = conn.prepareStatement(sql); ResultSet rs = ps.executeQuery(); while (rs.next()) { EntityAccessory entity = new EntityAccessory(); entity.setId(rs.getInt("id")); entity.setFileName(rs.getString("file_name")); entity.setFileSize(new BigDecimal(rs.getDouble("file_size") / 1024).setScale(2, BigDecimal.ROUND_HALF_UP).doubleValue()); entity.setFile_ext_name(rs.getString("file_ext_name")); entity.setFilePath(rs.getString("file_path")); accessoryList.add(entity); } DBUtil.close(rs, ps, conn); } catch (SQLException e) { e.printStackTrace(); } return accessoryList; } public static EntityAccessory load(int id){ Connection conn = DBUtil.getConnection(); PreparedStatement ps=null; ResultSet rs=null; EntityAccessory entity = new EntityAccessory(); String sql = "select id, file_name,file_size,file_ext_name,file_path from tbl_accessory where id=?"; try { ps = conn.prepareStatement(sql); ps.setInt(1,id); rs = ps.executeQuery(); while (rs.next()){ entity.setId(rs.getInt("id")); entity.setFileName(rs.getString("file_name")); entity.setFileSize(rs.getDouble("file_size")); entity.setFile_ext_name(rs.getString("file_ext_name")); entity.setFilePath(rs.getString("file_path")); } } catch (SQLException e) { e.printStackTrace(); }finally { DBUtil.close(rs,ps,conn); } return entity; } public static void remove(int id) { Connection conn = DBUtil.getConnection(); String sql = "delete from tbl_accessory where id=?"; try { PreparedStatement ps = conn.prepareStatement(sql); ps.setInt(1,id); ps.execute(); //conn.commit(); mysql默认开启了autocommit DBUtil.close(null,ps,conn); } catch (SQLException e) { e.printStackTrace(); } } } 

4.新增删除文件处理器,removeUploadedFileServlet

 package servlet.upload; import dao.upload.AccessoryDao; import entity.upload.EntityAccessory; import util.FileUtils; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; /** * 删除已上传文件 * * @author xusucheng * @create 2017-12-30 **/ @WebServlet("/removeUploadedFile") public class removeUploadedFileServlet extends HttpServlet { @Override protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //String filePath = request.getParameter("filePath"); int fileId = Integer.valueOf(request.getParameter("id")); EntityAccessory entity = AccessoryDao.load(fileId); //删除文件 FileUtils.delete(entity.getFilePath()); //删除数据库记录 AccessoryDao.remove(fileId); //跳回到文件列表页 //request.getRequestDispatcher("listUploadedFiles").forward(request, response); response.sendRedirect("listUploadedFiles"); } @Override protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request, response); } } 

5.测试效果截图

删除前:

删除后:

6.下集预告

实现文件下载功能

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