java呼叫pyzbar解析base64型的二維碼實踐優化
阿新 • • 發佈:2020-08-11
- Java程式碼
UserController.java
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,"; /** * 這種方式在原始碼中成功呼叫,但達成jar包後,找不到指令碼路徑,所以指令碼必須放在外面 */ @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字元的頭部 String base64Str = this.cutHead(base64); //2.建立臨時檔案(由於圖片的base64字元太長,不支援直接以命令引數的形式傳遞,故將字串寫入臨時檔案,而後python程式讀取臨時檔案內容) String tempPath = "./" + Thread.currentThread().getName(); File tempFile = new File(tempPath); FileWriter fileWriter = new FileWriter(tempFile, false); fileWriter.write(base64Str); fileWriter.flush(); fileWriter.close(); //3.呼叫pyzbar解析base64字串 String plainText = PyZbarUtil.executePyzbar("python", scriptPath, tempFile.getAbsolutePath()); //4.刪除臨時檔案 tempFile.delete(); System.err.println("--------->" + plainText); return plainText; } else { return "引數格式錯誤"; } } /** * 校驗Base64值是否已規定的串開始 * * @param base64 * @return */ private boolean checkBase64Head(String base64) { return base64.startsWith(BASE_64_PREFIX); } /** * Base64去頭 * * @param base64 * @return */ private String cutHead(String base64) { return base64.replaceAll(BASE_64_PREFIX, ""); } }
PyZbarUtil.java
package com.yang.springbootlucene.controller; import java.io.BufferedReader; import java.io.InputStreamReader; public final class PyZbarUtil { /** * 指令碼執行工具類 * * @param lang 命令語言 * @param scriptPath 指令碼絕對路勁 * @param base64Path base64檔案絕對路徑 * @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("指令碼呼叫失敗"); } } catch (Exception e) { e.printStackTrace(); } return null; } }
- python指令碼my_py_zbar.py
# -*-coding:UTF-8-*- import sys import base64 from io import BytesIO import pyzbar.pyzbar as pyzbar from PIL import Image,ImageEnhance '''將base64轉換為位元組流''' def convert_base64_to_byte_stream(base64_str): # 1.解碼Base64字串 img_data = base64.b64decode(base64_str) # 2.將節碼結果轉為位元組流 byte_stream = BytesIO(img_data) return byte_stream '''從將位元組流解析二維碼''' def parse_byte_stream_qr_code(byte_stream): # 3.開啟位元組流得到圖片物件 img = Image.open(byte_stream) img = ImageEnhance.Brightness(img).enhance(2.0) #增加亮度 img = ImageEnhance.Contrast(img).enhance(4.0) #增加對比度 # img = ImageEnhance.Sharpness(img).enhance(17.0) #銳利化 # img = img.convert('L') #灰度化 # img.show() # 播放圖片,供測試用 # 4.呼叫pyzbar解析圖片中的二維碼 barcodes = pyzbar.decode(img) # 5.列印解析結果 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)
- yaml配置項
pyzbar:
script: 'C:\Users\Tyrael\Desktop\pypy\script\my_py_zbar.py'
- 坑點:
- 圖片轉base64後,得到的字串太長,不能直接以命令引數的形式傳遞,所以必須將其寫入臨時檔案,然後python指令碼讀取臨時檔案進行解析
- 若將python指令碼放在專案中,專案打成jar包後,無法定位指令碼路徑,導致執行失敗,所以必須將指令碼放在jar包外,以配置的形式將路徑傳遞給java專案