标签：文件下载和文件上传
项目介绍：
本项目主要完成文件的上传以及下载的功能的一个综合案例.
1.搭建环境...
导入jar包以及开发的工具类...
jar包:
提供俩个工具类..一个是IOUtils主要提供了输出流和输入流的对接，和关闭流资源的函数
一个是提供数据源的工具类DataSourceUtils
IOUtils:
package cn.itheima.utils;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
public class IOUtils {
private IOUtils(){
}
/**
* 读取流中的数据写到输出流中
* @param in
* @param out
* @throws IOException
*/
public static void In2Out(InputStream in,OutputStream out) throws IOException{
int len=0;
byte b[]=new byte[1024];
while((len=in.read(b))!=-1){
out.write(b, 0, len);
}
}
/**
* 关闭资源
* @param in
* @param out
*/
public static void closeIO(InputStream in,OutputStream out){
if(in!=null){
try {
in.close();
} catch (IOException e) {
e.printStackTrace();
}finally{
in=null;
}
}
if(out!=null){
try {
out.close();
} catch (IOException e) {
e.printStackTrace();
}finally{
out=null;
}
}
}
}
DataSourceUtils:
package cn.itheima.utils;
import java.sql.Connection;
import java.sql.SQLException;
import javax.sql.DataSource;
import com.mchange.v2.c3p0.ComboPooledDataSource;
public class DataSourceUtil {
private static DataSource source = new ComboPooledDataSource();
private DataSourceUtil() {
}
public static DataSource getSource(){
return source;
}
public static Connection getConn(){
try {
return source.getConnection();
} catch (SQLException e) {
e.printStackTrace();
throw new RuntimeException(e);
}
}
}
2.准备好数据库:
create database day15;
use day15;
create table netdisk(
id int primary key auto_increment,
uuidname varchar(255),
realname varchar(255),
savepath varchar(255),
ip varchar(100),
uploadtime timestamp,
description varchar(255)
);
配置文件c3p0-config.xml
<?xml version="1.0" encoding="UTF-8"?>
<c3p0-config>
<default-config>
<property name="driverClass">com.mysql.jdbc.Driver</property>
<property name="jdbcUrl">jdbc:mysql://localhost:3306/day15?generateSimpleParameterMetadata=true</property>
<property name="user">root</property>
<property name="password">169500</property>
</default-config>
</c3p0-config>package cn.itheima.domain;
import java.io.Serializable;
import java.sql.Timestamp;
public class Resource implements Serializable{
private int id;
private String uuidname;//上传文件的名称,文件的uuid名
private String realname;//文件上传的真实名称
private String savepath;//文件上传的位置
private Timestamp uploadtime;//文件上传的时间
private String ip;//上传文件者的ip地址
private String description;//文件的描述信息
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getUuidname() {
return uuidname;
}
public void setUuidname(String uuidname) {
this.uuidname = uuidname;
}
public String getRealname() {
return realname;
}
public void setRealname(String realname) {
this.realname = realname;
}
public String getSavepath() {
return savepath;
}
public void setSavepath(String savepath) {
this.savepath = savepath;
}
public Timestamp getUploadtime() {
return uploadtime;
}
public void setUploadtime(Timestamp uploadtime) {
this.uploadtime = uploadtime;
}
public String getIp() {
return ip;
}
public void setIp(String ip) {
this.ip = ip;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
}
4.搭建项目的主页面:主要提供两个超链接：文件上传的超链接-->upload.jsp,文件下载列表的超链接-->
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title></title>
<meta http-equiv=" pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
</head>
<body>
<a href="${pageContext.request.contextPath }/upload.jsp">文件上传</a>
<a href="${pageContext.request.contextPath }/servlet/DownLoadListServlet">文件列表</a>
</body>
</html>
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title></title>
<meta http-equiv=" pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
</head>
<body>
<h1>文件上传</h1>
<form action="${pageContext.request.contextPath }/servlet/UploadServlet" enctype="multipart/form-data" method="post">
描述信息：<input type="text" name="description"/><br>
文件上传：<input type="file" name="file1"/><br>
<input type="submit" value="提交"/><br>
</form>
</body>
</html>
6.开发servlet类UploadServlet(需要在WEB-INF目录下建立temp临时文件夹以及upload的上传文件所在的文件夹)
(1).上传文件的步骤
(2).将拿到的数据封装到Resource的一个对象中...这里使用的是BeanUtils..
(3).添加数据到数据库中...
(4).重定向到主页..
注意：
这里保存到数据库的路径不是全路径而是截取硬盘路径后的路径...
封装数据拿不到所有的数据，因此自己建立一个map类封装数据...
这里采用的是hashcode的文件夹存储...
package cn.itheima.web;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.UUID;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.sql.DataSource;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import com.sun.org.apache.commons.beanutils.BeanUtils;
import cn.itheima.domain.Resource;
import cn.itheima.utils.DataSourceUtil;
import cn.itheima.utils.IOUtils;
public class UploadServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
Map map=new HashMap();
String ip= request.getRemoteAddr();
map.put("ip", ip);
try {
// 1.文件上传的工厂类
DiskFileItemFactory factory = new DiskFileItemFactory();
factory.setSizeThreshold(1024 * 1024 * 10);
factory.setRepository(new File(this.getServletContext()
.getRealPath("WEB-INF/temp")));
// 2.文件上传用到的核心类
ServletFileUpload fileUpload = new ServletFileUpload(factory);
fileUpload.setFileSizeMax(1024 * 1024 * 100);// 设置单个文件的大小
fileUpload.setFileSizeMax(1024 * 1024 * 300);// 设置总的文件的大小
fileUpload.setHeaderEncoding("utf-8");// 解决中文乱码的问题
// 3.判断表单的类型
if (!fileUpload.isMultipartContent(request)) {
throw new RuntimeException("请使用正确的表单类型");
}
// --解析request
List<FileItem> list = fileUpload.parseRequest(request);
//--遍历
for(FileItem item:list){
if(item.isFormField()){//普通字段
String name = item.getFieldName();
String value = item.getString("utf-8");
map.put(name, value);
}else{//文件上传字段
String realname = item.getName();
map.put("realname", realname);
String uuidname=UUID.randomUUID()+"_"+realname;
map.put("uuidname", uuidname);
String str = Integer.toHexString(uuidname.hashCode());
String path=this.getServletContext().getRealPath("WEB-INF/upload");
String savepath = "/WEB-INF/upload";
for(char c:str.toCharArray()){
path+="/"+c;
savepath+="/"+c;
}
map.put("savepath",savepath);
//--创建文件夹
new File(path).mkdirs();
InputStream in=item.getInputStream();
OutputStream out=new FileOutputStream(new File(path,uuidname));
IOUtils.In2Out(in, out);
IOUtils.closeIO(in, out);
item.delete();//删除临时文件
}
}
//2.存到数据库中
//--封装数据
Resource r=new Resource();
BeanUtils.populate(r,map);
QueryRunner runner=new QueryRunner(DataSourceUtil.getSource());
String sql="insert into netdisk values(null,?,?,?,?,null,?)";
runner.update(sql,r.getUuidname(),r.getRealname(),r.getId(),r.getSavepath(),r.getDescription());
//3.重定向回主页
response.sendRedirect(request.getContextPath()+"/index.jsp");
} catch (Exception e) {
throw new RuntimeException();
}
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}
7.回归到主页...开发DownLoadListServlet
(1).数据库查询数据封装到list集合中
(2).把list放到request域中...用于在列表显示..
(3).请求转发到list.jsp
package cn.itheima.web;
import java.io.IOException;
import java.sql.SQLException;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.sql.DataSource;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import cn.itheima.domain.Resource;
import cn.itheima.utils.DataSourceUtil;
public class DownLoadListServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//1.查询数据库
QueryRunner runner=new QueryRunner(DataSourceUtil.getSource());
String sql="select * from netdisk ";
List list=null;
try {
list=runner.query(sql, new BeanListHandler<Resource>(Resource.class));
} catch (SQLException e) {
e.printStackTrace();
}
request.setAttribute("list", list);
request.getRequestDispatcher("/list.jsp").forward(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}
8.开发list.jsp遍历list中的数据...
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title></title>
<meta http-equiv=" pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
</head>
<body>
<h1>下载列表</h1>
<c:forEach items="${requestScope.list }" var="li">
文件名：${li.realname }<br>
上传者ip:${li.ip }<br>
上传时间：${li.uploadtime}<br>
文件描述：${li.description }<br>
<a href="${pageContext.request.contextPath }/servlet/DownLoadServlet?id=${li.id}">下载</a><br>
</c:forEach>
</body>
</html>
9.开发DownLoadServlet(要注意的是下载的路径要拼接..因为存放到数据库中的路径是WEB-INF/upload....)
(1).获取id
(2).通过id查询数据库...拿到javaBean
(3).按照下载的步骤写代码...
(4).重定向到下载列表页面
package cn.itheima.web;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URLEncoder;
import java.sql.SQLException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.sql.DataSource;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
import cn.itheima.domain.Resource;
import cn.itheima.utils.DataSourceUtil;
import cn.itheima.utils.IOUtils;
public class DownLoadServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//1.获取下载文件的id
String id = request.getParameter("id");
Resource r=null;
String sql="select * from netdisk where id=?";
QueryRunner runner=new QueryRunner(DataSourceUtil.getSource());
try {
r=runner.query(sql, new BeanHandler<Resource>(Resource.class),id);
response.setHeader("Content-Disposition", "attchment;filename="+URLEncoder.encode(r.getRealname(),"utf-8"));
response.setContentType(this.getServletContext().getMimeType(r.getRealname()));
String path=r.getSavepath();
String savepath=this.getServletContext().getRealPath(path+"/"+r.getUuidname());
InputStream in=new FileInputStream(savepath);
OutputStream out=response.getOutputStream();
IOUtils.In2Out(in, out);
IOUtils.closeIO(in, out);
response.sendRedirect(request.getContextPath()+"/list.jsp");
} catch (SQLException e) {
e.printStackTrace();
}
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}
版权声明：本文为博主原创文章，未经博主允许不得转载。
标签：文件下载和文件上传
原文地址：http://blog.csdn.net/u014010769/article/details/46822179
