使用hibernate+srpingmvc实现文件(图片)上传和下载

需求:
文件上传，可以选择文件，上传者的名字。保存到数据库中
上传成功显示列表，上传的所有记录，显示上传者的名字，上传时间，附带连接，点击下载此文件。

配置:使用hibernate,所以要有hibernate.cfg.xml和生成表的xx.hbm.xml文件.
hibernate.cfg.xml配置:

<?xml version="1.0" encoding="UTF-8"?><hibernate-configuration>    <session-factory>        <!-- 基本配置：数据库连接信息(4个)+1(方言)+(1)创建表策略 +(2)sql语句输出 -->        <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>        <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/up_load</property>        <property name="hibernate.connection.username">root</property>        <property name="hibernate.connection.password">123</property>        <!-- 数据库方言 -->        <property name="hibernate.dialect">org.hibernate.dialect.MySQL5InnoDBDialect</property>        <property name="hibernate.hbm2ddl.auto">update</property>        <property name="hibernate.format_sql">true</property>        <property name="hibernate.show_sql">true</property>        <!-- getCurrentSession()调用必须有该配置 -->        <property name="current_session_context_class">thread</property>        <!-- 映射文件：目录 -->        <mapping resource="com/lm/pojo/fold.hbm.xml" />    </session-factory></hibernate-configuration>  

xx.hbm.xml文件配置:

<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE hibernate-mapping PUBLIC     "-//Hibernate/Hibernate Mapping DTD 3.0//EN"    "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"><hibernate-mapping package="com.lm.pojo">   <class name="Fold" table="fold">      <id name="id" >         <generator class="native"></generator>       </id>      <property name="person"></property>        <property name="time"></property>      <property name="path"  ></property>   </class></hibernate-mapping>

因为要使用springmvc,所以要有 springmvc的xml配置文件,因为上传的是文件,所以有 < bean id=”multipartResolver”>

<?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"    xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.1.xsd        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.1.xsd">    <!-- 扫描  -->    <context:component-scan base-package="com.lm.controller" />    <!--  配置映射解析器 -->    <bean id="internalResourceViewResolver"        class="org.springframework.web.servlet.view.InternalResourceViewResolver">        <!-- jsp文件存放在web-inf下，目的是为了强制用户必须先经过控制器，然后转发的jsp 因为在web-inf下的资源只能通过转发的方式访问到资源 -->        <property name="prefix" value="/WEB-INF/views/" />        <property name="suffix" value=".jsp" />    </bean>    <!-- 添加对文件上传功能的需求  -->    <bean id="multipartResolver"        class="org.springframework.web.multipart.commons.CommonsMultipartResolver">        <property name="defaultEncoding" value="UTF-8"></property>        <property name="maxUploadSize" value="1024000"></property>    </bean></beans>

pom.xml:

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">    <modelVersion>4.0.0</modelVersion>    <groupId>com.lm</groupId>    <artifactId>test13</artifactId>    <version>0.0.1-SNAPSHOT</version>    <dependencies>        <!-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc -->        <dependency>            <groupId>javax.servlet</groupId>            <artifactId>jstl</artifactId>            <version>1.2</version>        </dependency>        <dependency>            <groupId>org.springframework</groupId>            <artifactId>spring-webmvc</artifactId>            <version>4.3.10.RELEASE</version>        </dependency>        <!-- https://mvnrepository.com/artifact/javax/javaee-api -->        <dependency>            <groupId>javax</groupId>            <artifactId>javaee-api</artifactId>            <version>7.0</version>            <scope>provided</scope>        </dependency>        <dependency>            <groupId>commons-fileupload</groupId>            <artifactId>commons-fileupload</artifactId>            <version>1.3.1</version>        </dependency>        <!-- 数据库 -->        <dependency>            <groupId>org.hibernate</groupId>            <artifactId>hibernate-core</artifactId>            <version>5.1.0.Final</version>        </dependency>        <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->        <!-- mysql的connector包 -->        <dependency>            <groupId>mysql</groupId>            <artifactId>mysql-connector-java</artifactId>            <version>5.1.24</version>        </dependency>    </dependencies></project>

Controller类:

package com.lm.controller;import java.io.File;import java.io.IOException;import java.net.URLEncoder;import java.util.List;import java.util.UUID;import org.apache.commons.io.FileUtils;import org.springframework.core.serializer.support.SerializingConverter;import org.springframework.http.HttpHeaders;import org.springframework.http.HttpStatus;import org.springframework.http.MediaType;import org.springframework.http.ResponseEntity;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestParam;import org.springframework.web.context.WebApplicationContext;import org.springframework.web.context.support.WebApplicationContextUtils;import org.springframework.web.multipart.MultipartFile;import org.springframework.web.servlet.ModelAndView;import com.lm.dao.FileAddDao;import com.lm.pojo.Fold;@Controllerpublic class UpController {    @RequestMapping("/up")    public ModelAndView up(@RequestParam("file") MultipartFile multipartFile,String person) throws IllegalStateException, IOException {        //文件的名字        //String fileName = multipartFile.getOriginalFilename();        UUID name1 =  UUID.randomUUID();        String fileName = name1.toString()+".jpg";              System.out.println(fileName+"--"+person);        File file  = new File("D:\\picture\\"+fileName);        //String path1 = file.getPath();        //文件存在本地磁盘        multipartFile.transferTo(file);        Fold fold = new Fold();        fold.setPerson(person);        fold.setPath("/lm/"+fileName);        FileAddDao fileAddDao = new FileAddDao();        fileAddDao.addDao(fold);        FileAddDao fileAddDao1 = new FileAddDao();        List<Fold> list = fileAddDao1.findAll();        ModelAndView modelAndView = new ModelAndView("list");        modelAndView.addObject("list",list);        return modelAndView;    }    @RequestMapping("/load")    public ResponseEntity<byte[]> load(String path) throws IOException {        System.out.println("这是path---"+path);        //组装返回数据        //path.lastIndexOf("/")  找/ 最后一次出现的位置        //  path.substring(path.lastIndexOf("/")); 从/最后一次出现的位置 开始截取         String string = path.substring(path.lastIndexOf("/"));         File file = new File("D:\\picture\\"+string);         System.out.println(file.getPath());         byte[] files = FileUtils.readFileToByteArray(file);         //组装头部         HttpHeaders headers = new HttpHeaders();         headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);         headers.setContentDispositionFormData("attachment", URLEncoder.encode(file.getName(),"UTF-8"));        return new ResponseEntity<byte[]>(files,headers,HttpStatus.OK);    }}

dao层:

package com.lm.dao;import java.util.List;import org.hibernate.Query;import org.hibernate.Session;import org.hibernate.Transaction;import com.lm.pojo.Fold;import com.lm.utils.HibernateUtils;public class FileAddDao {    public void addDao(Fold fold) {        Session session = HibernateUtils.getCurrentSession();        Transaction transaction = session.beginTransaction();        try {            session.save(fold);            transaction.commit();        }catch(Exception e) {            System.out.println("事务回滚了");            transaction.rollback();        }     }    public List<Fold> findAll() {        Session session = HibernateUtils.getCurrentSession();        Transaction transaction = session.beginTransaction();        List<Fold> list =   session.createQuery("from Fold").list();        System.out.println("发的顺丰到付"+list);        return list;    }    /*public Fold findById(int id) {        Session session = HibernateUtils.getCurrentSession();        Transaction transaction = session.beginTransaction();        Fold fold = new Fold();        Query query = session.createQuery("from Fold where id = :id");        fold = (Fold) query.setParameter("id", id).uniqueResult();        System.out.println("这是fold  "+fold);        return fold;    }    */}

上传的jsp:

显示所有数据的jsp, 这个jsp是放在webcontent/web-inf/views目录下的,

总结:敲代码的过程中遇到了两个问题,1. 图片不能在浏览器进行显示 2.图片能显示之后不能下载(因为路径不对)

图片不能在浏览器进行显示:要在三个地方设置虚拟路径,
1.在Servers项目的server.xml的host的标签中加:< Context docBase=”D:\picture” path=”/lm/” debug=”0” reloadable=”true” />
2.在tomcat的安装目录下面,D:\software\tomcat\apache-tomcat-8.5.16\backup下面的server.xml做与上面同样的操作.
3.在D:\software\tomcat\apache-tomcat-8.5.16\conf下面的server.xml做与上面同样的操作.

这样直接获取虚拟路径在浏览器页面进行显示了,但是因为数据库存的是文件的虚拟路径,这样是下载不了文件的,所以将文件的名字和固定的存放上传文件的路径进行拼接,这样就获取到真实的文件路径了.

File file = new File(“D:\picture\”+string); new出来的是路径是由 \符号组成的,不是 /