小程序UniApp上传图片格式为Base64，后台如何接收,前端如何传Base64请求

电玩女神 2023-10-05 14:50 14阅读 0赞

**工具类**

package com.muyi.psi.rest.modular.auth.util;
    
    import org.springframework.web.multipart.MultipartFile;
    import sun.misc.BASE64Decoder;
     
    import java.io.*;
     
    /**
     * @Author: AppleSugar
     * @Description:base64解析类
     * @Date: Created in 19:14 2020/6/11
     * @Modified By:
     */
    public class BASE64DecodedMultipartFile implements MultipartFile{
        
        private final byte[] imgContent;
        private final String header;
     
        public BASE64DecodedMultipartFile(byte[] imgContent, String header) {
        
            this.imgContent = imgContent;
            this.header = header.split(";")[0];
        }
     
        @Override
        public String getName() {
        
            return System.currentTimeMillis() + Math.random() + "." + header.split("/")[1];
        }
     
        @Override
        public String getOriginalFilename() {
        
            return System.currentTimeMillis() + (int) Math.random() * 10000 + "." + header.split("/")[1];
        }
     
        @Override
        public String getContentType() {
        
            return header.split(":")[1];
        }
     
        @Override
        public boolean isEmpty() {
        
            return imgContent == null || imgContent.length == 0;
        }
     
        @Override
        public long getSize() {
        
            return imgContent.length;
        }
     
        @Override
        public byte[] getBytes() throws IOException {
        
            return imgContent;
        }
     
        @Override
        public InputStream getInputStream() throws IOException {
        
            return new ByteArrayInputStream(imgContent);
        }
     
        @Override
        public void transferTo(File dest) throws IOException, IllegalStateException {
        
            new FileOutputStream(dest).write(imgContent);
        }
     
        public static MultipartFile base64ToMultipart(String base64) {
        
            try {
        
                String[] baseStrs = base64.split(",");
     
                BASE64Decoder decoder = new BASE64Decoder();
                byte[] b = new byte[0];
                b = decoder.decodeBuffer(baseStrs[1]);
     
                for (int i = 0; i < b.length; ++i) {
        
                    if (b[i] < 0) {
        
                        b[i] += 256;
                    }
                }
                return new BASE64DecodedMultipartFile(b, baseStrs[0]);
            } catch (IOException e) {
        
                e.printStackTrace();
                return null;
            }
        }
    }

**base64 是公共接口 先调用公共的上传图片接口！ 然后前端回显存入服务器的图片URL ， 在把URL从添加的接口 添加数据库里！**

/**
         * base64接受图片
         * @param base
         * @param request
         * @return
         */
        @PostMapping("/base64")
        @ResponseBody
        public Object  base(String base,HttpServletRequest request){
        
            MultipartFile  file= BASE64DecodedMultipartFile.base64ToMultipart(base);
            String url = uploadFile(request, file);
            return  url;
        }
    
    
    //   //上传文件
    //    @PostMapping("/multipart")
    //    @ResponseBody
        public String uploadFile(HttpServletRequest request, MultipartFile mediaFile) {
        
            String result = "false";
            if (!mediaFile.isEmpty()&&!mediaFile.getOriginalFilename().equals("null")) {
        
                File targetFile = null;
                String url = "";//返回存储路径
                String fileName = mediaFile.getOriginalFilename();
                if (fileName != null && fileName != "") {
        
                    String fileF = fileName.substring(fileName.lastIndexOf("."), fileName.length());//文件后缀
                    fileName = new Date().getTime() + "_" + new Random().nextInt(1000) + fileF;//新的文件名
                    //先判断文件是否存在
                    SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd");
                    String fileAdd = sdf.format(new Date());
                    //获取文件夹路径
                    File file1 = new File(path + "/" + fileAdd);
                    //如果文件夹不存在则创建
                    if (!file1.exists() && !file1.isDirectory()) {
        
                        file1.mkdirs();
                    }
                    //将图片存入文件夹
                    targetFile = new File(file1, fileName);
                    try {
        
                        //将上传的文件写到服务器上指定的文件。
                        mediaFile.transferTo(targetFile);
                        url = returnUrl + fileAdd + "/" + fileName;
                        return url;
                    } catch (Exception e) {
        
                        e.printStackTrace();
                        return "false";
                    }
                }
            }
            return result;
        }

这个是前端调用的请求方式

imglist_msg(e){
        
         console.log(e)
         uni.request({
        
             url: 'https://xxx.com/base64', //仅为示例，并非真实接口地址。
             data: {
        
                 base: e[0]
             },
          method:'POST',
             header: {
        
                 'Content-Type': "application/x-www-form-urlencoded", //自定义请求头信息
             },
             success: (res) => {
        
                 console.log(res);
                 // this.text = 'request success';
             }
         });
        },

如果前端传的图片值是base64加密的 就需要后台方法接收 解密

/**
         * Base64解密
         */
        private static String decodeBase64(String str) throws UnsupportedEncodingException {
        
            byte[] decoded = Base64.getDecoder().decode(str);
            String decodeStr =  new String(decoded);
            return URLDecoder.decode(decodeStr,"utf-8");
        }