springmvc 图片上传、展示及下载

1、需要添加在pom.xml中添加

<dependency>
    <groupId>commons-fileupload</groupId>
    <artifactId>commons-fileupload</artifactId>
    <version>1.3.1</version>
</dependency>

2、需要在spring.xml配置文件中设置文件可上传的最大文件

<!-- 配置文件上传 -->
<bean id="multipartResolver"
      class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
    <!-- 配置文件上传的最大体积 30M -->
    <property name="maxUploadSize" value="30720000"></property>
</bean>

3、上传文件类

package com.tn.controller;

import com.tn.entity.po.UploadPO;
import com.tn.result.Result;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.util.UUID;

/**
 * @author ：abel.he
 * @date ：Created in 2021/12/22 14:09
 * @description：文件上传
 * @modified By：
 */
@RestController
@Slf4j
public class UploadController {

    @Value("${file.upload.path}")
    private String fileUploadPath;

    @PostMapping("upload")
    public Result upload(MultipartFile file) {
        // 原始文件名
        String originalFileName = file.getOriginalFilename();
        // 获取图片后缀
        String suffix = originalFileName.substring(originalFileName.lastIndexOf("."));
        // 生成图片存储的名称，UUID 避免相同图片名冲突，并加上图片后缀
        String fileName = UUID.randomUUID().toString() + suffix;
        // 图片存储路径
        String filePath = fileUploadPath + fileName;
        File saveFile = new File(filePath);
        try {
            // 将上传的文件保存到服务器文件系统
            file.transferTo(saveFile);
            // 记录服务器文件系统图片名称
        } catch (IOException e) {
            log.error(e.getMessage(), e);
        }

        UploadPO uploadPO = new UploadPO();
        uploadPO.setFilePath(filePath);
        uploadPO.setFileName(originalFileName);
        uploadPO.setSaveFilePath("");
        return Result.success(uploadPO);
    }

    /**
     * 处理图片显示请求
     * @param fileName
     */
    @RequestMapping("/showPic/{fileName}.{suffix}")
    public void showPicture(@PathVariable("fileName") String fileName,
                            @PathVariable("suffix") String suffix,
                            HttpServletResponse response){
        File imgFile = new File(fileUploadPath + fileName + "." + suffix);
        responseFile(response, imgFile);
    }

    /**
     * 处理图片下载请求
     * @param fileName
     * @param response
     */
    @GetMapping("/downloadPic/{fileName}.{suffix}")
    public void downloadPicture(@PathVariable("fileName") String fileName,
                                @PathVariable("suffix") String suffix,
                                HttpServletResponse response){
        // 设置下载的响应头信息
        response.setHeader("Content-Disposition",
                "attachment;fileName=" + "headPic.jpg");
        File imgFile = new File(fileUploadPath + fileName + "." + suffix);
        responseFile(response, imgFile);
    }

    /**
     * 响应输出图片文件
     * @param response
     * @param imgFile
     */
    private void responseFile(HttpServletResponse response, File imgFile) {
        try(InputStream is = new FileInputStream(imgFile);
            OutputStream os = response.getOutputStream();){
            byte [] buffer = new byte[1024];
            while(is.read(buffer) != -1){
                os.write(buffer);
            }
            os.flush();
        } catch (IOException ioe){
            ioe.printStackTrace();
        }
    }

}

 

参考资料：

https://www.jianshu.com/p/5fc5b10fc8dc