springboot+web文件上传和下载

一、首先安装mysql数据库，开启web服务器。

二、pom.xml文件依赖包配置如下：

<?xml version="1.0" encoding="UTF-8"?>
<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>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.1.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <groupId>com.weChat</groupId>
    <artifactId>SmallProject</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>SmallProject</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.38</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <optional>true</optional>
        </dependency>

        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>3.8.1</version>
            <scope>test</scope>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

二、使用IDE建立springboot+web工程，连接数据库的application.properties配置如下：

 1 #服务器端口设置
 2 server.port=8080
 3 #必须包含项目名称
 4 #server.servlet.context-path=/demo
 5 #数据库配置信息
 6 spring.datasource.driver-class-name=com.mysql.jdbc.Driver
 7 spring.datasource.url=jdbc:mysql://localhost:3306/demo?useUnicode=true&characterEncoding=utf8&useSSL=false
 8 spring.datasource.username=root
 9 spring.datasource.password=******
10 #设置单个上传文件的大小
11 spring.servlet.multipart.max-file-size=200GB
12 #设置一次请求上传文件的总量
13 spring.servlet.multipart.max-request-size=200GB
14 spring.jpa.hibernate.ddl-auto=update
15 spring.jpa.show-sql=true

三、建立数据库表格的Test.java内容如下：

 package com.wechat.smallproject.dataBaseTable;

 import javax.persistence.Column;
 import javax.persistence.Entity;
 import javax.persistence.Id;
 import javax.persistence.Table;
 import java.util.Date;

 /**
  * @Author CFF
  * @Date:Created in 16:25 2019/1/10
  */
 @Table(name = "picture_info")
 @Entity
 public class Test {
     @Id
     /**
      * 主键ID
      */
     @Column(length = 32)
     private Integer Id;
     /**
      * 图片名称
      */
     private String pictureName;
     /**
      * 图片格式
      */
     private String pictureFormat;
     /**
      * 图片上传存放地址
      */
     private String picturePath;
     /**
      * 图片上传大小
      */
     private long pictureSize;
     /**
      * 上传图片时间
      */
     private Date uploadPictureTime;

     public Integer getId() {
         return Id;
     }

     public void setId(Integer id) {
         Id = id;
     }

     public String getPictureName() {
         return pictureName;
     }

     public void setPictureName(String pictureName) {
         this.pictureName = pictureName;
     }

     public String getPictureFormat() {
         return pictureFormat;
     }

     public void setPictureFormat(String pictureFormat) {
         this.pictureFormat = pictureFormat;
     }

     public String getPicturePath() {
         return picturePath;
     }

     public void setPicturePath(String picturePath) {
         this.picturePath = picturePath;
     }

     public long getPictureSize() {
         return pictureSize;
     }

     public void setPictureSize(long pictureSize) {
         this.pictureSize = pictureSize;
     }

     public Date getUploadPictureTime() {
         return uploadPictureTime;
     }

     public void setUploadPictureTime(Date uploadPictureTime) {
         this.uploadPictureTime = uploadPictureTime;
     }

 }

四、建立TestDao.java接口，用来保存数据库表信息：

 package com.wechat.smallproject.dao;

 import com.wechat.smallproject.dataBaseTable.Test;
 import org.springframework.data.jpa.repository.JpaRepository;

 /**
  * @Author CFF
  * @Date:Created in 16:45 2019/1/10
  */
 public interface TestDao extends JpaRepository<Test,Integer> {
 }

五、建立TestController.java，编写文件上传和下载方法。

 package com.wechat.smallproject.controller;

 import com.wechat.smallproject.dao.TestDao;
 import com.wechat.smallproject.dataBaseTable.Test;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.web.bind.annotation.*;
 import org.springframework.web.multipart.MultipartFile;
 import org.springframework.web.multipart.support.StandardMultipartHttpServletRequest;

 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import java.io.*;
 import java.text.SimpleDateFormat;
 import java.util.*;

 /**
  * @Author CFF
  * @Date:Created in 16:47 2019/1/10
  */
 @RestController
 public class TestController {
     @Autowired
     TestDao testDao;

     public String pictureName=null ;
     public String picturePath=null ;

     @RequestMapping(value = "/upload")
     public void uploadPicture(HttpServletRequest request) throws Exception {
         //获取文件需要上传到的路径
         picturePath = "C:\\Users\\CFF\\Desktop\\Project\\PicturesPath\\";

         // 判断存放上传文件的目录是否存在（不存在则创建）
         File dir = new File(picturePath);
         if (!dir.exists()) {
             dir.mkdir();
         }
         try {
             StandardMultipartHttpServletRequest req = (StandardMultipartHttpServletRequest) request;
             //获取formdata的值
             Iterator<String> iterator = req.getFileNames();
             while (iterator.hasNext()) {
                 MultipartFile file=req.getFile(iterator.next());
                 //获取文件后缀名
                 String fileSuffixName=file.getOriginalFilename().substring(86);
                 //真正写到磁盘上
                 //全球唯一id
                 String uuid= UUID.randomUUID().toString().replace("-","");
                 pictureName=uuid+fileSuffixName;
                 //将文件信息存入数据库中
                 Test test =new Test();
                 if(new Date().hashCode()<0){
                     test.setId(-new Date().hashCode());
                 }
                 else{
                     test.setId(new Date().hashCode());
                 }
                 test.setUploadPictureTime(new Date());
                 test.setPictureName(uuid);
                 test.setPicturePath(picturePath+pictureName);
                 test.setPictureSize(file.getSize());
                 test.setPictureFormat(file.getContentType());
                 testDao.save(test);

                 File file1=new File(picturePath+pictureName);
                 OutputStream out=new FileOutputStream(file1);
                 out.write(file.getBytes());
                 out.close();
                 System.out.println("图片上传成功！");
             }
         } catch (Exception e) {
             System.out.println(e);
         }
     }
     //文件下载相关代码
     @RequestMapping("/download")
     public void fileDownload( HttpServletResponse response){
         File file = new File(picturePath+pictureName);
         if (pictureName != null) {
             if (file.exists()) {
                 response.setContentType("application/force-download");// 设置强制下载不打开
                 Date currentTime = new Date();
                 SimpleDateFormat dateFormat = new SimpleDateFormat("yyyyMMddHHmmss");
                 String dataTime=dateFormat.format(currentTime);
                 //文件重新命名
                 String pictureNewName = dataTime+pictureName.substring(pictureName.indexOf("."));
                 response.addHeader("Content-Disposition",
                         "attachment;fileName=" + pictureNewName);// 设置文件名
                 byte[] buffer = new byte[1024];
                 FileInputStream fis = null;
                 BufferedInputStream bis = null;
                 try {
                     fis = new FileInputStream(file);
                     bis = new BufferedInputStream(fis);
                     OutputStream os = response.getOutputStream();
                     int i = bis.read(buffer);
                     while (i != -1) {
                         os.write(buffer, 0, i);
                         i = bis.read(buffer);
                     }
                     System.out.println(pictureNewName+"下载成功！！！");
                 } catch (Exception e) {
                     e.printStackTrace();
                     System.out.println(pictureNewName+"下载失败！！！"+e);
                 } finally {
                     if (bis != null) {
                         try {
                             bis.close();
                         } catch (IOException e) {
                             e.printStackTrace();
                         }
                     }
                     if (fis != null) {
                         try {
                             fis.close();
                         } catch (IOException e) {
                             e.printStackTrace();
                         }
                     }
                 }
             }
         }
     }
 }

六、upload.html如下：

 <!DOCTYPE html>
 <html lang="en">
 <head>
     <title>上传图片</title>
     <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
 </head>
 <body>
 <form action="/upload" method="post" enctype="multipart/form-data">
     文件：<input type="file" name="filename"/>
     <input type="submit" value="提交"/>
 </form>
 <a href="/download">下载</a>
 </body>
 </html>