Java调用pyzbar解析base64二维码过程解析

package com.yang.springbootlucene.controller;

import lombok.Data;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.core.io.ClassPathResource;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;

/**
 * @author:yjx
 * @description:
 * @date:2019/11/28 15:29
 */
@Slf4j
@RestController
@RequestMapping("/user")
public class UserController {

  @Value("${pyzbar.script}")
  private String scriptPath;

  private static final String BASE_64_PREFIX = "data:image/png;base64,";

  /**
   * 这种方式在源码中成功调用，但达成jar包后，找不到脚本路径，所以脚本必须放在外面
   */
  @Deprecated
  private static String pyZbarScriptPath;
  /* static {
    ClassPathResource pathResource = new ClassPathResource("/script/my_py_zbar.py");
    try {
      pyZbarScriptPath = pathResource.getFile().getAbsolutePath();
    } catch (IOException e) {
      e.printStackTrace();
    }
  } */

  @RequestMapping("/cameraScanPyZbar")
  public Object cameraScanPyZbar(@RequestBody String base64) throws IOException {
    if (this.checkBase64Head(base64)) {
      //1.去掉base64字符的头部
      String base64Str = this.cutHead(base64);

      //2.创建临时文件（由于图片的base64字符太长，不支持直接以命令参数的形式传递，故将字符串写入临时文件，而后python程序读取临时文件内容）
      String tempPath = "./" + Thread.currentThread().getName();
      File tempFile = new File(tempPath);
      FileWriter fileWriter = new FileWriter(tempFile, false);
      fileWriter.write(base64Str);
      fileWriter.flush();
      fileWriter.close();

      //3.调用pyzbar解析base64字符串
      String plainText = PyZbarUtil.executePyzbar("python", scriptPath, tempFile.getAbsolutePath());

      //4.删除临时文件
      tempFile.delete();
      System.err.println("--------->" + plainText);
      return plainText;
    } else {
      return "参数格式错误";
    }
  }

  /**
   * 校验Base64值是否已规定的串开始
   *
   * @param base64
   * @return
   */
  private boolean checkBase64Head(String base64) {
    return base64.startsWith(BASE_64_PREFIX);
  }

  /**
   * Base64去头
   *
   * @param base64
   * @return
   */
  private String cutHead(String base64) {
    return base64.replaceAll(BASE_64_PREFIX, "");
  }
}

package com.yang.springbootlucene.controller;

import java.io.BufferedReader;
import java.io.InputStreamReader;

public final class PyZbarUtil {

  /**
   * 脚本执行工具类
   *
   * @param lang    命令语言
   * @param scriptPath 脚本绝对路劲
   * @param base64Path   base64文件绝对路径
   * @return
   */
  public static String executePyzbar(String lang, String scriptPath, String base64Path) {
    String[] arguments = new String[]{lang, scriptPath, base64Path};
    try {
      Process process = Runtime.getRuntime().exec(arguments);
      int re = process.waitFor();
      if (re == 0) {
        try (BufferedReader in = new BufferedReader(new InputStreamReader(process.getInputStream(), "GBK"));) {
          return in.readLine();
        }
      } else {
        System.err.println("脚本调用失败");
      }
    } catch (Exception e) {
      e.printStackTrace();
    }
    return null;
  }
}

# -*-coding:UTF-8-*-

import sys
import base64
from io import BytesIO
import pyzbar.pyzbar as pyzbar
from PIL import Image,ImageEnhance


'''将base64转换为字节流'''
def convert_base64_to_byte_stream(base64_str):
  # 1.解码Base64字符串
  img_data = base64.b64decode(base64_str)

  # 2.将节码结果转为字节流
  byte_stream = BytesIO(img_data)
  return byte_stream


'''从将字节流解析二维码'''
def parse_byte_stream_qr_code(byte_stream):
  # 3.打开字节流得到图片对象
  img = Image.open(byte_stream)

  img = ImageEnhance.Brightness(img).enhance(2.0) #增加亮度
  img = ImageEnhance.Contrast(img).enhance(4.0) #增加对比度
  # img = ImageEnhance.Sharpness(img).enhance(17.0) #锐利化
  # img = img.convert('L') #灰度化

  # img.show() # 播放图片，供测试用

  # 4.调用pyzbar解析图片中的二维码
  barcodes = pyzbar.decode(img)

  # 5.打印解析结果
  return barcodes[0].data.decode("utf-8")


def main(argv):
#  print(parse_byte_stream_qr_code(convert_base64_to_byte_stream(argv[1])))
  print(parse_byte_stream_qr_code(convert_base64_to_byte_stream(open(argv[1]).readline())))


if __name__ == "__main__":
  main(sys.argv)