web文件上传与下载综合案例（数据库） 刺骨的言语ヽ痛彻心扉 2022-05-20 07:16 62阅读 0赞 > 之前发布了有关于文件上传和下载的一些知识，今天我结合数据库使用SpringMvc技术做了一个web版本的比较使用的上传与下载案例。步骤如下： > > 一、准备环境 > > (1)创建一个web工程 > > (2)准备工程需要的jar包(在这里我多导入了一些，防止因为缺少jar包，出现错误) ![70][] > (3)编写application.xml和springmvc.xml，代码如下： > > application.xml: > > <?xml version="1.0" encoding="UTF-8"?> > <beans xmlns="http://www.springframework.org/schema/beans" > xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" > xmlns:mvc="http://www.springframework.org/schema/mvc" > xmlns:context="http://www.springframework.org/schema/context" > xmlns:aop="http://www.springframework.org/schema/aop" > xmlns:tx="http://www.springframework.org/schema/tx" > xsi:schemaLocation="http://www.springframework.org/schema/beans > http://www.springframework.org/schema/beans/spring-beans-3.2.xsd > http://www.springframework.org/schema/mvc > http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd > http://www.springframework.org/schema/context > http://www.springframework.org/schema/context/spring-context-3.2.xsd > http://www.springframework.org/schema/aop > http://www.springframework.org/schema/aop/spring-aop-3.2.xsd > http://www.springframework.org/schema/tx > http://www.springframework.org/schema/tx/spring-tx-3.2.xsd "> > > <!-- 配置数据源 --> > <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"> > <property name="driverClassName" value="com.mysql.jdbc.Driver"/> > <property name="url" value="jdbc:mysql://localhost:3306/webuploadanddown?useUnicode=true&characterEncoding=utf8"/> > <property name="username" value="root"/> > <property name="password" value="410923"/> > </bean> > > <!-- 配置SqlSessionFactory --> > <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> > <property name="dataSource" ref="dataSource"/> > <property name="mapperLocations" value="classpath:com/nyist/cn/Dao/Impl/UpfileDao.xml"/> > </bean> > > <!-- 配置mapper扫描器 --> > <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> > <property name="sqlSessionFactory" ref="sqlSessionFactory"/> > <property name="basePackage" value="com.nyist.cn.Dao"/> > </bean> > > </beans> > > > > springmvc.xml: > > <?xml version="1.0" encoding="UTF-8"?> > <beans xmlns="http://www.springframework.org/schema/beans" > xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" > xmlns:mvc="http://www.springframework.org/schema/mvc" > xmlns:context="http://www.springframework.org/schema/context" > xmlns:aop="http://www.springframework.org/schema/aop" > xmlns:tx="http://www.springframework.org/schema/tx" > xsi:schemaLocation="http://www.springframework.org/schema/beans > http://www.springframework.org/schema/beans/spring-beans-3.2.xsd > http://www.springframework.org/schema/mvc > http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd > http://www.springframework.org/schema/context > http://www.springframework.org/schema/context/spring-context-3.2.xsd > http://www.springframework.org/schema/aop > http://www.springframework.org/schema/aop/spring-aop-3.2.xsd > http://www.springframework.org/schema/tx > http://www.springframework.org/schema/tx/spring-tx-3.2.xsd "> > > <!-- 配置组件扫描 --> > <context:component-scan base-package="com.nyist.cn"></context:component-scan> > > <!-- 配置mvc注解驱动 --> > <mvc:annotation-driven></mvc:annotation-driven> > > <!-- 配置视图解析器 --> > <!-- 配置sprigmvc视图解析器：解析逻辑试图，前缀+逻辑试图+后缀====/WEB-INF/jsps/xxx.jsp --> > <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> > <property name="prefix" value="/WEB-INF/pages/"/> > <property name="suffix" value=".jsp"/> > </bean> > > > </beans> > > > > (4)修改web.xml，配置控制器，加载以上两个配置文件，web.xml代码如下： > > <?xml version="1.0" encoding="UTF-8"?> > <web-app version="3.0" > xmlns="http://java.sun.com/xml/ns/javaee" > xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" > xsi:schemaLocation="http://java.sun.com/xml/ns/javaee > http://java.sun.com/xml/ns/javaee/web-app\_3\_0.xsd"> > > <!-- 配置字符编码过滤器 --> > <filter> > <filter-name>CharacterEncoding</filter-name> > <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class> > <init-param> > <param-name>encoding</param-name> > <param-value>UTF-8</param-value> > </init-param> > </filter> > <filter-mapping> > <filter-name>CharacterEncoding</filter-name> > <url-pattern>/\*</url-pattern> > </filter-mapping> > > > <!-- 配置自动装载配置文件的监听器ContenLoaderListener,自动装载配置文件 --> > <listener> > <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> > </listener> > > <!-- 加载spring配置文件，当spring的配置文件在classpath下时，需要配置以下内容以供web容器进行加载 --> > <!-- 如果不配置的时候，默认的路径是/WEB-INF/applicationContext.xml --> > <context-param> > <param-name>contextConfigLocation</param-name> > <param-value>classpath:application.xml</param-value> > </context-param> > > <!-- 配置控制器 --> > <servlet> > <servlet-name>UploadAndDownload</servlet-name> > <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> > <init-param> > <param-name>contextConfigLocation</param-name> > <param-value>classpath:springmvc.xml</param-value> > </init-param> > </servlet> > <servlet-mapping> > <servlet-name>UploadAndDownload</servlet-name> > <url-pattern>\*.apex</url-pattern> > </servlet-mapping> > > </web-app> > > > > (5)测试数据源能否获得 > > package com.nyist.cn.Test; > > > import org.junit.Test; > import org.springframework.context.support.ClassPathXmlApplicationContext; > > > public class TestDataSource \{ > > @Test > public void test1()\{ > ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("application.xml"); > Object obj = context.getBean("sqlSessionFactory"); > System.out.println("Connection:"+obj); > \} > > \} > > > > 运行结果：Connection:org.apache.ibatis.session.defaults.DefaultSqlSessionFactory@3349e9bb > > > > 二、ORM映射 > > (1)第一步Object，建实体Upfile.java，代码如下： > > package com.nyist.cn.model; > > //实体 > public class Upfile \{ > private String id; //文件ID > private String uuidname; //uuid文件名称 > private String filename; //文件的真实名称 > private String savepath; //文件的保存路径 > private String uptime; //文件上传时间 > private String description; //文件的描述 > private String username; //上传的用户 > > public String getDescription() \{ > return description; > \} > public void setDescription(String description) \{ > this.description = description; > \} > public String getId() \{ > return id; > \} > public void setId(String id) \{ > this.id = id; > \} > public String getUuidname() \{ > return uuidname; > \} > public void setUuidname(String uuidname) \{ > this.uuidname = uuidname; > \} > public String getFilename() \{ > return filename; > \} > public void setFilename(String filename) \{ > this.filename = filename; > \} > public String getSavepath() \{ > return savepath; > \} > public void setSavepath(String savepath) \{ > this.savepath = savepath; > \} > public String getUptime() \{ > return uptime; > \} > public void setUptime(String uptime) \{ > this.uptime = uptime; > \} > public String getUsername() \{ > return username; > \} > public void setUsername(String username) \{ > this.username = username; > \} > public Upfile() \{ > super(); > \} > public Upfile(String id, String uuidname, String filename, String savepath, String uptime,String description, String username) \{ > super(); > this.id = id; > this.uuidname = uuidname; > this.filename = filename; > this.savepath = savepath; > this.uptime = uptime; > this.description = description; > this.username = username; > \} > @Override > public String toString() \{ > return "upfile \[id=" + id + ", uuidname=" + uuidname + ", filename=" + filename + ", savepath=" + savepath > \+ ", uptime=" + uptime + ",description="+description+", username=" + username + "\]"; > \} > \} > > (2)第二部R,Relational,即数据库的关系表 > > ①创建数据库 > > //创建一个字符编码为UTF-8并且带有校对规则的数据库 > > create database webUploadAndDownload character set utf8 collate utf8\_general\_ci; > > ②创建数据表 > > create table upfile( > > id varhcar(40) primary key, > > uuidname varchar(100) not null, > > filename varchar(100) not null, > > savepath varchar(255) not null, > > uptime datetime not null, > > description varchar(255), > > username varchar(40) not null > > ); > > > > (3)第三步M,Mapping映射，使用Mybatis 的配置文件将Java对象映射到数据库表中 > > 示例： > > <insert id="addfile" parameterType="com.nyist.cn.model.Upfile"> > insert into upfile(id,uuidname,filename,savepath,uptime,description,username) values(\#\{id\},\#\{uuidname\},\#\{filename\},\#\{savepath\},\#\{uptime\},\#\{description\},\#\{username\}) > > </insert> > > > > (4)编写Dao层，为了是数据库和程序持久化，我们在配置文件中创建了Bean工厂，在实现Dao接口时，我采用配置配置文件来实现Dao中的方法 > > UpfileDao.java 如下： > > package com.nyist.cn.Dao; > > > import java.util.List; > > > import com.nyist.cn.model.Upfile; > > > public interface UpfileDao \{ > > //添加文件 > public void addfile(Upfile upfile); > > \} > > > > UpfileDaoImpl.xml如下： > > <?xml version="1.0" encoding="UTF-8"?> > <!DOCTYPE mapper > PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" > "http://mybatis.org/dtd/mybatis-3-mapper.dtd"> > > > <mapper namespace="com.nyist.cn.Dao.UpfileDao"> > <insert id="addfile" parameterType="com.nyist.cn.model.Upfile"> > insert into upfile(id,uuidname,filename,savepath,uptime,description,username) values(\#\{id\},\#\{uuidname\},\#\{filename\},\#\{savepath\},\#\{uptime\},\#\{description\},\#\{username\}) > </insert> > > <select id="getAllFile" resultType="com.nyist.cn.model.Upfile"> > select \* from upfile order by uptime desc > </select> > > <select id="findUpfile" parameterType="java.lang.String" resultType="com.nyist.cn.model.Upfile"> > select \* from upfile where id = \#\{id\} > </select> > > <delete id="deleteupfile" parameterType="java.lang.String"> > delete from upfile where id = \#\{id\} > </delete> > > </mapper> > > (5)编写UpfileService接口和UpfileServiceImpl.java > > UpfileService 接口如下： > > package com.nyist.cn.Service; > > > import java.util.List; > > > import com.nyist.cn.model.Upfile; > > > public interface UpfileService \{ > //添加文件 > public void addfile(Upfile upfile); > > \} > > UpfileServiceImpl.java如下： > > package com.nyist.cn.Service.Impl; > > > import java.util.List; > > > import org.springframework.beans.factory.annotation.Autowired; > import org.springframework.stereotype.Service; > > > import com.nyist.cn.Dao.UpfileDao; > import com.nyist.cn.Service.UpfileService; > import com.nyist.cn.model.Upfile; > > > @Service > public class UpfileServiceImpl implements UpfileService\{ > > > @Autowired > private UpfileDao upfileDao ; > > @Override > public void addfile(Upfile upfile) \{ > upfileDao.addfile(upfile); > > \} > > \} > > (6)编写Controller > > 代码如下: > > package com.nyist.cn.Controller; > > > import java.io.File; > import java.io.FileInputStream; > import java.io.FileNotFoundException; > import java.io.IOException; > import java.io.OutputStream; > import java.lang.reflect.InvocationTargetException; > import java.net.URLEncoder; > import java.util.List; > > > import javax.servlet.ServletException; > import javax.servlet.http.HttpServletRequest; > import javax.servlet.http.HttpServletResponse; > > > import org.apache.commons.fileupload.servlet.ServletFileUpload; > import org.springframework.beans.factory.annotation.Autowired; > import org.springframework.stereotype.Controller; > import org.springframework.web.bind.annotation.RequestMapping; > > > import com.nyist.cn.Service.UpfileService; > import com.nyist.cn.Utils.WebUtils; > import com.nyist.cn.model.Upfile; > @Controller > public class UpfileController \{ > > @Autowired > private UpfileService upfileService ; > /\*\* > \* 后台 jsp 页面访问 > \* @return > \*/ > @RequestMapping("index") > public String index()\{ > return "index"; > \} > > @RequestMapping("message") > public String message()\{ > return "message"; > \} > > @RequestMapping("head") > public String head()\{ > return "head"; > \} > > @RequestMapping("upload") > public String upload()\{ > return "upload"; > \} > > @RequestMapping("showdownload") > public String showdownload()\{ > return "showdownload"; > \} > > > @RequestMapping("UploadAction") > public void Upload(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException, IllegalAccessException, InvocationTargetException\{ > //拿到前台传进来的数据 首先判断是否为mutipart/form-data提交方式 > if(!ServletFileUpload.isMultipartContent(request))\{ > request.setAttribute("message","上传的不是为有效的数据类型"); > request.getRequestDispatcher("/message.apex").forward(request, response); > return ; > \} > //得到保存文件 的目录 > String path = request.getSession().getServletContext().getRealPath("/WEB-INF/upload"); > //制作WebUtils 工具类 封装request 和 savepath > Upfile upfile = WebUtils.doUpload(request,path); > upfileService.addfile(upfile); > System.out.println("Upfile:"+upfile); > request.setAttribute("message","上传成功！"); > request.getRequestDispatcher("/message.apex").forward(request, response); > \} > > @RequestMapping("listfileAction") > public void listfile(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException\{ > String method = request.getMethod(); > if("GET".equals(method))\{ > List<Upfile> list = upfileService.getAllFile(); > request.setAttribute("list",list); > request.getRequestDispatcher("/showdownload.apex").forward(request, response); > return ; > \} > \} > > @RequestMapping("DownLoadAction") > public void DownLoad(HttpServletRequest request,HttpServletResponse response) throws IOException, ServletException\{ > //拿到前台数据 > String id = request.getParameter("id"); > Upfile upfile = upfileService.findUpfile(id); > System.out.println("Upfile:"+upfile); > File file = new File(upfile.getSavepath()+File.separator+upfile.getUuidname()); > System.out.println("File:"+file); > if(!file.exists())\{ > request.setAttribute("message","下载资源已被删除"); > request.getRequestDispatcher("/message.apex").forward(request, response); > return ; > \} > response.setHeader("content-disposition","attachment;filename="+URLEncoder.encode(upfile.getFilename(),"UTF-8")); > try \{ > FileInputStream in = new FileInputStream(file); > OutputStream out = response.getOutputStream(); > int len =0; > byte buffer\[\] = new byte\[1024\]; > while((len = in.read(buffer))>0)\{ > out.write(buffer, 0, len); > \} > in.close(); > \} catch(FileNotFoundException e) \{ > e.printStackTrace(); > throw new RuntimeException(e); > \} > \} > > \} > > > > (7)测试运行结果如下 > > ![70 1][] [70]: /images/20220520/f3727d43a9cf4b66ab0adbdf5f8e2fce.png [70 1]: /images/20220520/ebf52040d4034d778ec4594a59403074.png
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