代码

base64Url 不能有前缀data:image/jpeg;base64,或者data:image/png;base64,
里面没用的字符要替换干净，比如像 \n、[“、”]、这些都是无用字符串，需要清除。

@Api("测试base64Url转存本地")
@RestController
@Slf4j
public class TestController {
    @PostMapping("/test")
    public void getBase64Url(@RequestBody String base64Url) {
        String url = "/Users/super0/Desktop/1.png";
//        String newUrl = "/home/op/project/file/leerhuo-business-server/1.png";
        String newBase64Url = base64Url.replace("\\n", "").replace("[\"", "").replace("\"]", "");
        log.info("新地址：" + newBase64Url);
        BASE64Decoder decoder = new BASE64Decoder();
        try {
            // Base64解码
            byte[] b = decoder.decodeBuffer(newBase64Url);
            for (int i = 0; i < b.length; ++i) {
                if (b[i] < 0) {
                    b[i] += 256;
                }
            }
            OutputStream out = new FileOutputStream(url);
            out.write(b);
            out.flush();
            out.close();
        } catch (Exception ignored) {
        }
    }
}