在SpringBoot中实现文件上传-编程知识

在SpringBoot中实现文件上传

1.创建一个SpringBoot的项目，需要导入spring-boot-starter-web的依赖

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

2.编写文件的核心配置application.properties

server.port=2100
#文件的保存地址
file-save-path=D:/a/f/picture/#是否开启文件上传支持，默认为true。
spring.servlet.multipart.enabled=true 
#文件写入磁盘的阈值，默认为0。
spring.servlet.multipart.file-size-threshold=0
#上传文件的临时保存位置。
spring.servlet.multipart.location=D:/1javaweb/b
#上传的单个文件的最大大小，默认为1MB。
spring.servlet.multipart.max-file-size=30MB
#多文件上传时文件的总大小，默认为10MB。
spring.servlet.multipart.max-request-size=10MB
#文件是否延迟解析，默认为false。
spring.servlet.multipart.resolve-lazily=false

3.编写控制层

import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;
import javax.servlet.http.HttpServletRequest;
import java.io.File;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.UUID;@RestController
public class FileUploadController {@Value("${file-save-path}")private String fileSavePath;SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd/");@RequestMapping("/upload")public String upload(MultipartFile uploadFile, HttpServletRequest req) {String filePath = "";String format = sdf.format(new Date());File folder = new File(fileSavePath + format);if (!folder.isDirectory()) {folder.mkdirs();String oldName = uploadFile.getOriginalFilename();String newName = UUID.randomUUID().toString() +oldName.substring(oldName.lastIndexOf("."), oldName.length());try {uploadFile.transferTo(new File(folder, newName));filePath = req.getScheme() + "://" + req.getServerName() + ":" +req.getServerPort() + "/uploadFile/" + format + newName;} catch (IOException e) {return "上传失败! ";}}String oldName = uploadFile.getOriginalFilename();String newName = UUID.randomUUID().toString().replace("-","") +oldName.substring(oldName.lastIndexOf("."), oldName.length());try {uploadFile.transferTo(new File(folder, newName));filePath = req.getScheme() + "://" + req.getServerName() + ":" +req.getServerPort() + "/uploadFile/" + format + newName;} catch (IOException e) {return "上传失败! ";}return filePath;}
}

4.在resources下创建static目录，然后创建update.html页面

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><title>Title</title></head>
<body><!--enctype 属性规定在发送到服务器之前应该如何对表单数据进行编码。-->
<form action="/upload" method="post" enctype="multipart/form-data"><input type="file" name="uploadFile" value="请选择文件" required><input type="submit" value="上传">
</form>
</body>
</html>

5.如果想要在缓存中查询刚刚上传的文件或图片，需要添加以下配置类

import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;@Configuration
public class WebConfig implements WebMvcConfigurer {@Value("${file-save-path}")private String fileSavePath;@Overridepublic void addResourceHandlers(ResourceHandlerRegistry registry) {registry.addResourceHandler("/uploadFile/**").addResourceLocations("file:"+fileSavePath);}
}

6.如果想要任何ip都能访问，需要添加以下配置类

import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.CorsRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;@Configuration
public class CarsConfig implements WebMvcConfigurer {@Overridepublic void addCorsMappings(CorsRegistry registry) {registry.addMapping("/**")//所有的都配置跨域.allowedOrigins("*")//所有的请求可以访问跨域的资源.allowedHeaders("*")//所有的请求头都可以访问.allowedMethods("GET","POST","PUT","DELETE","HEAD","OPTION")//什么类型的请求都可以访问后端资源.maxAge(3600)//服务端存储相关信息的时间      秒;}
}

7.启动我们的SpringBoot项目，访问该地址