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" %> <html> <head> <title>上传文件列表</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>文件大小（KB）</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" >删除</a></td> </tr> </c:forEach> </c:if> </table> </body> </html>
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<EntityAccessory> list() {
Connection conn = DBUtil.getConnection();
String sql = "select id,file_name,file_size,file_ext_name,file_path from tbl_accessory";
List<EntityAccessory> 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
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。
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