接著上一篇講：Jsp+Servlet實(shí)現(xiàn)文件上傳下載（二）--文件列表展示
本章來實(shí)現(xiàn)一下刪除已上傳文件，同時(shí)優(yōu)化了一下第一章中的代碼。
廢話少說，上代碼得意
1.調(diào)整列表頁面list.jsp
%@ page contentType="text/html;charset=UTF-8" language="java" %>
%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
html>
head>
title>上傳文件列表/title>
/head>
body>
h3>文件列表/h3>
table class="acclist_tab" border="1" bordercolor="#000000" cellspacing="0" cellpadding="2" style="border-collapse:collapse;">
tr>
th>文件名/th>
th>文件大?。↘B）/th>
th>操作/th>
/tr>
c:if test="${not empty accessoryList}">
c:forEach items="${accessoryList}" var="acc">
tr>
td>${acc.fileName}/td>
td>${acc.fileSize}/td>
td>a href="%=request.getContextPath()%>/removeUploadedFile?id=${acc.id}" rel="external nofollow" >刪除/a>/td>
/tr>
/c:forEach>
/c:if>
/table>
/body>
/html>
2.新增FileUtils工具類
package util;
import java.io.File;
/**
* 文件操作工具類
*
* @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("刪除失敗，文件："+path+"不存在！");
return false;
}
file.delete();
return true;
}
}
3.調(diào)整附件實(shí)體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;
/**
* 附件上傳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 ListEntityAccessory> list() {
Connection conn = DBUtil.getConnection();
String sql = "select id,file_name,file_size,file_ext_name,file_path from tbl_accessory";
ListEntityAccessory> 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默認(rèn)開啟了autocommit
DBUtil.close(null,ps,conn);
} catch (SQLException e) {
e.printStackTrace();
}
}
}
4.新增刪除文件處理器，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;
/**
* 刪除已上傳文件
*
* @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);
//刪除文件
FileUtils.delete(entity.getFilePath());
//刪除數(shù)據(jù)庫記錄
AccessoryDao.remove(fileId);
//跳回到文件列表頁
//request.getRequestDispatcher("listUploadedFiles").forward(request, response);
response.sendRedirect("listUploadedFiles");
}
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doPost(request, response);
}
}
5.測(cè)試效果截圖
刪除前：
刪除后：
6.下集預(yù)告
實(shí)現(xiàn)文件下載功能
以上就是本文的全部內(nèi)容，希望對(duì)大家的學(xué)習(xí)有所幫助，也希望大家多多支持腳本之家。
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