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Jsp+Servlet实现文件上传下载 文件列表展示(二)_JSP编程_

2023-05-25 329人已围观

简介 Jsp+Servlet实现文件上传下载 文件列表展示(二)_JSP编程_

接着上一篇讲:
Jsp+Servlet实现文件上传下载(一)--文件上传

本章来实现一下上传文件列表展示,同时优化了一下第一章中的代码。

废话少说,上代码

mysql创建附件表

 DROP TABLE tbl_accessory; CREATE TABLE tbl_accessory ( id INT AUTO_INCREMENT PRIMARY KEY, file_name VARCHAR(500), file_size DOUBLE(10,2), file_ext_name VARCHAR(100), file_path VARCHAR(2000) ) ; SELECT * FROM tbl_accessory; DELETE FROM tbl_accessory; 

创建附件实体类

 package entity.upload; /** * 附件实体类 * * @author xusucheng * @create 2017-12-29 **/ public class EntityAccessory { private int id; private String fileName; private double fileSize; private String file_ext_name; private String filePath; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getFileName() { return fileName; } public void setFileName(String fileName) { this.fileName = fileName; } public double getFileSize() { return fileSize; } public void setFileSize(double fileSize) { this.fileSize = fileSize; } public String getFile_ext_name() { return file_ext_name; } public void setFile_ext_name(String file_ext_name) { this.file_ext_name = file_ext_name; } public String getFilePath() { return filePath; } public void setFilePath(String filePath) { this.filePath = filePath; } } 

创建DBUtil工具类

 package util; import java.sql.*; import java.io.InputStream; import java.util.Properties; /** * 数据库工具类 * * @author xusucheng * @create 2017-11-18 **/ public class DBUtil { //定义链接所需要的变量 private static Connection con = null; private static PreparedStatement ps = null; private static ResultSet rs = null; //定义链接数据库所需要的参数 private static String url = ""; private static String username = ""; private static String driver=""; private static String password=""; //定义读取配置文件所需要的变量 private static Properties pp = null; private static InputStream fis = null; /** * 加载驱动 */ static { try { //从dbinfo.properties配置文件中读取配置信息 pp = new Properties(); fis = DBUtil.class.getClassLoader().getResourceAsStream("db.properties"); pp.load(fis); url = pp.getProperty("url"); username = pp.getProperty("username"); driver=pp.getProperty("driver"); password=pp.getProperty("password"); //加载驱动 Class.forName(driver); } catch (Exception e) { System.out.println("驱动加载失败!"); e.printStackTrace(); } finally { try { fis.close(); } catch (Exception e) { e.printStackTrace(); } fis = null; //垃圾回收自动处理 } } /** * 得到Connection链接 * @return Connection */ public static Connection getConnection() { try { //建立连接 con = DriverManager.getConnection(url, username, password); } catch (Exception e) { System.out.println("数据库链接失败!"); e.printStackTrace(); } return con; } /*public DBUtil(String sql){ try { ps = getConnection().prepareStatement(sql);//准备执行语句 } catch (Exception e) { e.printStackTrace(); } } public void close() { try { con.close(); ps.close(); } catch (SQLException e) { e.printStackTrace(); } }*/ /** * 统一的资源关闭函数 * @param rs * @param ps * @param con */ public static void close(ResultSet rs,Statement ps, Connection con){ if(rs != null) { try { rs.close(); } catch (Exception e) { e.printStackTrace(); } } if(ps != null) { try { ps.close(); } catch (Exception e) { e.printStackTrace(); } } if(con != null) { try { con.close(); } catch (Exception e) { e.printStackTrace(); } } } } 

创建附件实体DAO类

 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 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(); } } } 

创建list.jsp列表页面

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

创建展示列表Servlet:listUploadedFilesServlet

 package servlet.upload; import dao.upload.AccessoryDao; import entity.upload.EntityAccessory; 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; import java.util.List; /** * 返回已上传文件列表 * * @author xusucheng * @create 2017-12-29 **/ @WebServlet("/listUploadedFiles") public class listUploadedFilesServlet extends HttpServlet { @Override protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //获取文件列表 List accessoryList = AccessoryDao.list(); request.setAttribute("accessoryList", accessoryList); request.getRequestDispatcher("pages/upload/list.jsp").forward(request, response); } @Override protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request, response); } } 

增加error.jsp显示上传失败信息

<%@ page contentType="text/html;charset=UTF-8" language="java" %><%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>上传错误页面

上传失败:

<%----%>

${errorMessage}

优化了第一章中的上传控制器

 package servlet.upload; import dao.upload.AccessoryDao; import entity.upload.EntityAccessory; import org.apache.commons.fileupload.FileItem; import org.apache.commons.fileupload.FileUploadBase; import org.apache.commons.fileupload.FileUploadException; import org.apache.commons.fileupload.ProgressListener; import org.apache.commons.fileupload.disk.DiskFileItemFactory; import org.apache.commons.fileupload.servlet.ServletFileUpload; 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.File; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.util.Calendar; import java.util.Iterator; import java.util.List; import java.util.UUID; /** * 处理文件上传 * * @author xusucheng * @create 2017-12-27 **/ @WebServlet("/UploadServlet") public class UploadServlet extends HttpServlet { @Override protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //设置文件上传基本路径 String savePath = this.getServletContext().getRealPath("/WEB-INF/uploadFiles"); //设置临时文件路径 String tempPath = this.getServletContext().getRealPath("/WEB-INF/tempFiles"); File tempFile = new File(tempPath); if (!tempFile.exists()) { tempFile.mkdir(); } //定义异常消息 String errorMessage = ""; //创建file items工厂 DiskFileItemFactory factory = new DiskFileItemFactory(); //设置缓冲区大小 factory.setSizeThreshold(1024 * 100); //设置临时文件路径 factory.setRepository(tempFile); //创建文件上传处理器 ServletFileUpload upload = new ServletFileUpload(factory); //监听文件上传进度 ProgressListener progressListener = new ProgressListener() { public void update(long pBytesRead, long pContentLength, int pItems) { System.out.println("正在读取文件: " + pItems); if (pContentLength == -1) { System.out.println("已读取: " + pBytesRead + " 剩余0"); } else { System.out.println("文件总大小:" + pContentLength + " 已读取:" + pBytesRead); } } }; upload.setProgressListener(progressListener); //解决上传文件名的中文乱码 upload.setHeaderEncoding("UTF-8"); //判断提交上来的数据是否是上传表单的数据 if (!Servlet
                
                

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