Jsp+Servlet实现文件上传下载 删除上传文件（三）
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2022-04-28 22:48:37
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...
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。