tess4j:
  datapath: D:/tmp

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>springboot-demo</artifactId>
        <groupId>com.et</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>Tess4j</artifactId>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-autoconfigure</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <!-- tess4j -->
        <dependency>
            <groupId>net.sourceforge.tess4j</groupId>
            <artifactId>tess4j</artifactId>
            <version>4.5.4</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
    </dependencies>
</project>

package com.et.tess4j.controller;

import com.et.tess4j.service.OcrService;
import lombok.AllArgsConstructor;
import net.sourceforge.tess4j.TesseractException;
import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

@RestController
@AllArgsConstructor

public class HelloWorldController {
    @RequestMapping("/hello")
    public Map<String, Object> showHelloWorld(){
        Map<String, Object> map = new HashMap<>();
        map.put("msg", "HelloWorld");
        return map;
    }
   private final OcrService ocrService;

   @PostMapping(value = "/recognize", consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
   public String recognizeImage(@RequestParam("file") MultipartFile file) throws TesseractException, IOException {

      return ocrService.recognizeText(file);
   }
}

package com.et.tess4j.service;

import lombok.AllArgsConstructor;
import net.sourceforge.tess4j.*;
import org.springframework.stereotype.Service;
import org.springframework.web.multipart.MultipartFile;

import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;

@Service
@AllArgsConstructor
public class OcrService {

    private final Tesseract tesseract;

  
    public String recognizeText(MultipartFile imageFile) throws TesseractException, IOException {

        InputStream sbs = new ByteArrayInputStream(imageFile.getBytes());
        BufferedImage bufferedImage = ImageIO.read(sbs);

        return tesseract.doOCR(bufferedImage);
    }
}

package com.et.tess4j.config;

import net.sourceforge.tess4j.Tesseract;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;


@Configuration
public class TesseractOcrConfiguration {

   @Value("${tess4j.datapath}")
   private String dataPath;

   @Bean
   public Tesseract tesseract() {

      Tesseract tesseract = new Tesseract();
      tesseract.setDatapath(dataPath);
      tesseract.setLanguage("chi_sim");
      return tesseract;
   }
}