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.ModelAndVi
e5cb
ew;

import com.lm.dao.FileAddDao;
import com.lm.pojo.Fold;

@Controller
public 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 /