SpringBoot项目（百度AI整合）——如何在Springboot中使用文字识别OCR入门

前言

前言：本系列博客尝试结合官网案例，阐述百度 AI 开放平台里的组件使用方式，核心是如何在spring项目中快速上手应用。

本文介绍如何在Springboot中使用百度AI的文字识别OCR

其他相关的使用百度AI的文章列表如下：

如何在Springboot中使用语音文件识别 & ffmpeg的安装和使用

引出

---

1.从官网demo到idea中使用；
2.如何阅读官网的说明文档，小经验分享；

小经验：如何使用官方文档

https://ai.baidu.com/ai-doc/index/OCR

https://ai.baidu.com/ai-doc/OCR/Ek3h7xypm

1.API文档的使用

万里长征第一步，Ctrl c + v，复制粘贴

2.HTTP-SDK文档的使用

网络请求SDK案例

基于官网案例demo的实现

从官网的案例到spring项目整合

1.使用AipOcr客户端

BaiduOcrPro实体类

package com.tianju.config.baidu;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.PropertySource;
import org.springframework.stereotype.Component;

/**
 * OCR相关的配置
 */

@Component
@ConfigurationProperties(prefix = "baidu.ocr")
@PropertySource("classpath:config/baiduAip.properties")

@Data
@NoArgsConstructor
@AllArgsConstructor
public class BaiduOcrPro {
    
    
    private String appId;
    private String apiKey;
    private String secretKey;
}

初始化AipOcr，放到spring容器中

package com.tianju.config.baidu;

import com.baidu.aip.ocr.AipOcr;
import com.baidu.aip.speech.AipSpeech;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

/**
 * 百度相关的配置文件
 */
@Configuration
public class BaiduConfig {
    
    

    @Autowired
    private BaiduOcrPro baiduOcrPro;

    /**
     * 图像相关的 AipOcr
     * @return AipOcr 放容器中
     */
    @Bean
    public AipOcr aipOcr(){
    
    
        AipOcr aipOcr = new AipOcr(baiduOcrPro.getAppId(),
                baiduOcrPro.getApiKey(),
                baiduOcrPro.getSecretKey());
        // 可选：设置网络连接参数
        aipOcr.setConnectionTimeoutInMillis(2000);
        aipOcr.setSocketTimeoutInMillis(60000);
        return aipOcr;
    }

}

controller层进行调用

package com.tianju.config.controller;

import com.baidu.aip.ocr.AipOcr;
import com.tianju.config.resp.HttpResp;
import com.tianju.config.util.baidu.Base64Util;
import com.tianju.config.util.baidu.FileUtil;
import com.tianju.config.util.baidu.HttpUtil;
import org.json.JSONArray;
import org.json.JSONObject;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.net.URLEncoder;
import java.util.HashMap;


@RestController
@RequestMapping("/api/baidu/ocr")
public class BaiduOCRController {
    
    

    @Autowired
    private AipOcr aipOcr;

    // http://124.70.138.34:9000/hello/1.jpg
    @GetMapping("/imgUrl")
    public HttpResp ocrFromImgUrl(String imgUrl){
    
    

        // 传入可选参数调用接口
        HashMap<String, String> options = new HashMap<String, String>();
        options.put("language_type", "CHN_ENG");
        options.put("detect_direction", "true");
        options.put("detect_language", "true");
        options.put("probability", "true");

        /**
         * 网络图像
         */
        JSONObject res = aipOcr.basicGeneralUrl(
                imgUrl,
                options
        );

        /**
         * {"words_result":
         * [{"probability":{"average":0.9994496107,"min":0.9990026355,"variance":1.469044975E-7},
         *  "words":"爱我中华"}],
         * "log_id":1705920508293856573,"words_result_num":1,"language":3,"direction":0}
         */

        JSONArray wordsResult = (org.json.JSONArray)res.get("words_result");
        JSONObject o = (JSONObject) wordsResult.get(0);
        Object words = o.get("words");
        System.out.println(words);

        System.out.println("######################");
        System.out.println(res.toString(2));
        return HttpResp.success(words);
    }

}

2.使用官网的HttpUtil工具类

package com.tianju.config.controller;

import com.baidu.aip.ocr.AipOcr;
import com.tianju.config.resp.HttpResp;
import com.tianju.config.util.baidu.Base64Util;
import com.tianju.config.util.baidu.FileUtil;
import com.tianju.config.util.baidu.HttpUtil;
import org.json.JSONArray;
import org.json.JSONObject;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.net.URLEncoder;
import java.util.HashMap;


@RestController
@RequestMapping("/api/baidu/ocr")
public class BaiduOCRController {
    
    

    /**
     * 以下为官网的案例,token的方式
     * https://ai.baidu.com/ai-doc/OCR/zk3h7xz52
     */
    public static String generalBasic() {
    
    
        // 请求url
        String url = "https://aip.baidubce.com/rest/2.0/ocr/v1/general_basic";
        try {
    
    
            // 本地文件路径
            String filePath = "D:\\Myprogram\\springboot-workspace\\spring-project\\baidu-api\\src\\main\\resources\\static\\ocr_test.jpg";
            byte[] imgData = FileUtil.readFileByBytes(filePath);
            String imgStr = Base64Util.encode(imgData);
            String imgParam = URLEncoder.encode(imgStr, "UTF-8");

            String param = "image=" + imgParam;
            System.out.println(param);

            // 注意这里仅为了简化编码每一次请求都去获取access_token，线上环境access_token有过期时间， 客户端可自行缓存，过期后重新获取。
            String accessToken = "24.2f4d3e23a805ba89627472c38addcdcd.2592000.1698147302.282335-38781099";

            String result = HttpUtil.post(url, accessToken, param);
            System.out.println(result);
            return result;
        } catch (Exception e) {
    
    
            e.printStackTrace();
        }
        return null;
    }

    public static void main(String[] args) {
    
    
        generalBasic();
    }
}

附录：官网的工具类

1.Base64Util图片编码工具

package com.tianju.config.util.baidu;

/**
 * Base64 工具类
 */
public class Base64Util {
    
    
    private static final char last2byte = (char) Integer.parseInt("00000011", 2);
    private static final char last4byte = (char) Integer.parseInt("00001111", 2);
    private static final char last6byte = (char) Integer.parseInt("00111111", 2);
    private static final char lead6byte = (char) Integer.parseInt("11111100", 2);
    private static final char lead4byte = (char) Integer.parseInt("11110000", 2);
    private static final char lead2byte = (char) Integer.parseInt("11000000", 2);
    private static final char[] encodeTable = new char[]{
    
    'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/'};

    public Base64Util() {
    
    
    }

    public static String encode(byte[] from) {
    
    
        StringBuilder to = new StringBuilder((int) ((double) from.length * 1.34D) + 3);
        int num = 0;
        char currentByte = 0;

        int i;
        for (i = 0; i < from.length; ++i) {
    
    
            for (num %= 8; num < 8; num += 6) {
    
    
                switch (num) {
    
    
                    case 0:
                        currentByte = (char) (from[i] & lead6byte);
                        currentByte = (char) (currentByte >>> 2);
                    case 1:
                    case 3:
                    case 5:
                    default:
                        break;
                    case 2:
                        currentByte = (char) (from[i] & last6byte);
                        break;
                    case 4:
                        currentByte = (char) (from[i] & last4byte);
                        currentByte = (char) (currentByte << 2);
                        if (i + 1 < from.length) {
    
    
                            currentByte = (char) (currentByte | (from[i + 1] & lead2byte) >>> 6);
                        }
                        break;
                    case 6:
                        currentByte = (char) (from[i] & last2byte);
                        currentByte = (char) (currentByte << 4);
                        if (i + 1 < from.length) {
    
    
                            currentByte = (char) (currentByte | (from[i + 1] & lead4byte) >>> 4);
                        }
                }

                to.append(encodeTable[currentByte]);
            }
        }

        if (to.length() % 4 != 0) {
    
    
            for (i = 4 - to.length() % 4; i > 0; --i) {
    
    
                to.append("=");
            }
        }

        return to.toString();
    }
}

2.FileUtil读取文件工具类

package com.tianju.config.util.baidu;

import java.io.*;

/**
 * 文件读取工具类
 */
public class FileUtil {
    
    

    /**
     * 读取文件内容，作为字符串返回
     */
    public static String readFileAsString(String filePath) throws IOException {
    
    
        File file = new File(filePath);
        if (!file.exists()) {
    
    
            throw new FileNotFoundException(filePath);
        } 

        if (file.length() > 1024 * 1024 * 1024) {
    
    
            throw new IOException("File is too large");
        } 

        StringBuilder sb = new StringBuilder((int) (file.length()));
        // 创建字节输入流  
        FileInputStream fis = new FileInputStream(filePath);  
        // 创建一个长度为10240的Buffer
        byte[] bbuf = new byte[10240];  
        // 用于保存实际读取的字节数  
        int hasRead = 0;  
        while ( (hasRead = fis.read(bbuf)) > 0 ) {
    
      
            sb.append(new String(bbuf, 0, hasRead));  
        }  
        fis.close();  
        return sb.toString();
    }

    /**
     * 根据文件路径读取byte[] 数组
     */
    public static byte[] readFileByBytes(String filePath) throws IOException {
    
    
        File file = new File(filePath);
        if (!file.exists()) {
    
    
            throw new FileNotFoundException(filePath);
        } else {
    
    
            ByteArrayOutputStream bos = new ByteArrayOutputStream((int) file.length());
            BufferedInputStream in = null;

            try {
    
    
                in = new BufferedInputStream(new FileInputStream(file));
                short bufSize = 1024;
                byte[] buffer = new byte[bufSize];
                int len1;
                while (-1 != (len1 = in.read(buffer, 0, bufSize))) {
    
    
                    bos.write(buffer, 0, len1);
                }

                byte[] var7 = bos.toByteArray();
                return var7;
            } finally {
    
    
                try {
    
    
                    if (in != null) {
    
    
                        in.close();
                    }
                } catch (IOException var14) {
    
    
                    var14.printStackTrace();
                }

                bos.close();
            }
        }
    }
}

3.基于Google的gson的Json工具类

/*
 * Copyright (C) 2017 Baidu, Inc. All Rights Reserved.
 */
package com.tianju.config.util.baidu;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.JsonParseException;

import java.lang.reflect.Type;

/**
 * Json工具类.
 */
public class GsonUtils {
    
    
    private static Gson gson = new GsonBuilder().create();

    public static String toJson(Object value) {
    
    
        return gson.toJson(value);
    }

    public static <T> T fromJson(String json, Class<T> classOfT) throws JsonParseException {
    
    
        return gson.fromJson(json, classOfT);
    }

    public static <T> T fromJson(String json, Type typeOfT) throws JsonParseException {
    
    
        return (T) gson.fromJson(json, typeOfT);
    }
}

4.Http请求发起和获得响应工具类

package com.tianju.config.util.baidu;

import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.List;
import java.util.Map;

/**
 * http 工具类
 */
public class HttpUtil {
    
    

    public static String post(String requestUrl, String accessToken, String params)
            throws Exception {
    
    
        String contentType = "application/x-www-form-urlencoded";
        return HttpUtil.post(requestUrl, accessToken, contentType, params);
    }

    public static String post(String requestUrl, String accessToken, String contentType, String params)
            throws Exception {
    
    
        String encoding = "UTF-8";
        if (requestUrl.contains("nlp")) {
    
    
            encoding = "GBK";
        }
        return HttpUtil.post(requestUrl, accessToken, contentType, params, encoding);
    }

    public static String post(String requestUrl, String accessToken, String contentType, String params, String encoding)
            throws Exception {
    
    
        String url = requestUrl + "?access_token=" + accessToken;
        return HttpUtil.postGeneralUrl(url, contentType, params, encoding);
    }

    public static String postGeneralUrl(String generalUrl, String contentType, String params, String encoding)
            throws Exception {
    
    
        URL url = new URL(generalUrl);
        // 打开和URL之间的连接
        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
        connection.setRequestMethod("POST");
        // 设置通用的请求属性
        connection.setRequestProperty("Content-Type", contentType);
        connection.setRequestProperty("Connection", "Keep-Alive");
        connection.setUseCaches(false);
        connection.setDoOutput(true);
        connection.setDoInput(true);

        // 得到请求的输出流对象
        DataOutputStream out = new DataOutputStream(connection.getOutputStream());
        out.write(params.getBytes(encoding));
        out.flush();
        out.close();

        // 建立实际的连接
        connection.connect();
        // 获取所有响应头字段
        Map<String, List<String>> headers = connection.getHeaderFields();
        // 遍历所有的响应头字段
        for (String key : headers.keySet()) {
    
    
            System.err.println(key + "--->" + headers.get(key));
        }
        // 定义 BufferedReader输入流来读取URL的响应
        BufferedReader in = null;
        in = new BufferedReader(
                new InputStreamReader(connection.getInputStream(), encoding));
        String result = "";
        String getLine;
        while ((getLine = in.readLine()) != null) {
    
    
            result += getLine;
        }
        in.close();
        System.err.println("result:" + result);
        return result;
    }
}

---

总结

1.从官网demo到idea中使用；
2.如何阅读官网的说明文档，小经验分享；