SpringbootJAVAJava进阶之路

5、基于SpringBoot的文件上传

2019-03-26  本文已影响357人  Rebirth_914

文件上传的三种方法

SpringBoot文件上传示例——前后端不分离

1.创建upload模块项目
2.添加web、thymeleaf依赖

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

3.配置上传属性application.properties，指定上传文件大小限制等

#文件上传的配置
spring.servlet.multipart.max-file-size=100MB

4.编写Controller，通过java.nio实现稳健的上传

package com.springboot.upload.controller;

import org.springframework.stereotype.Controller;
import org.springframework.util.ResourceUtils;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.servlet.mvc.support.RedirectAttributes;

import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.UUID;

/**
 * 上传文件控制器
 * 直接上传到服务器
 *
 */
@Controller
public class UploadController {
    //指定一个临时路径作为上传目录
    //private static String UPLOAD_FOLDER = "C:\\Users\\Liuyu\\Desktop\\UPLOAD\\";

    //遇到http://localhost:8080，则跳转至upload.html页面
    @GetMapping("/")
    public String index() {
        return "upload";
    }

    @PostMapping("upload")
    public String fileUpload(@RequestParam("file")MultipartFile srcFile, RedirectAttributes redirectAttributes) {
        //前端没有选择文件，srcFile为空
        if(srcFile.isEmpty()) {
            redirectAttributes.addFlashAttribute("message", "请选择一个文件");
            return "redirect:upload_status";
        }
        //选择了文件，开始上传操作
        try {
            //构建上传目标路径，找到了项目的target的classes目录
            File destFile = new File(ResourceUtils.getURL("classpath:").getPath());
            if(!destFile.exists()) {
                destFile = new File("");
            }
            //输出目标文件的绝对路径
            System.out.println("file path:"+destFile.getAbsolutePath());
            //拼接子路径
            SimpleDateFormat sf_ = new SimpleDateFormat("yyyyMMddHHmmss");
            String times = sf_.format(new Date());
            File upload = new File(destFile.getAbsolutePath(), "static/"+times);
            //若目标文件夹不存在，则创建
            if(!upload.exists()) {
                upload.mkdirs();
            }
            System.out.println("完整的上传路径："+upload.getAbsolutePath()+"/"+srcFile);
            //根据srcFile大小，准备一个字节数组
            byte[] bytes = srcFile.getBytes();
            //拼接上传路径
            //Path path = Paths.get(UPLOAD_FOLDER + srcFile.getOriginalFilename());
            //通过项目路径，拼接上传路径
            Path path = Paths.get(upload.getAbsolutePath()+"/"+srcFile.getOriginalFilename());
            //** 开始将源文件写入目标地址
            Files.write(path, bytes);
            String uuid = UUID.randomUUID().toString().replaceAll("-", "");
// 获得文件原始名称
            String fileName = srcFile.getOriginalFilename();
// 获得文件后缀名称
            String suffixName = fileName.substring(fileName.lastIndexOf(".") + 1).toLowerCase();
// 生成最新的uuid文件名称
            String newFileName = uuid + "."+ suffixName;
            redirectAttributes.addFlashAttribute("message", "文件上传成功"+newFileName);
        } catch (IOException e) {
            e.printStackTrace();
        }
        return "redirect:upload_status";
    }

    //匹配upload_status页面
    @GetMapping("upload_status")
    public String uploadStatusPage() {
        return "upload_status";
    }
}

5.控制器配置好thymeleaf的页面跳转及信息显示

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Spring Boot文件上传页面</title>
</head>
<body>
<form method="post" action="/upload" enctype="multipart/form-data">
    <input type="file" name="file" >
    <input type="submit" value="上传">
</form>
</body>
</html>

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>文件上传状态显示</title>
</head>
<body>
<h2>SpringBoot文件上传状态</h2>
<div th:if="${message}">
    <h2 th:text="${message}"/>
</div>
</body>
</html>

6.运行项目，上传文件，观察结果


1.png 2.png
上一篇下一篇

猜你喜欢

热点阅读