How to Elegantly Perform OCR in Spring Boot 3 Using Tess4J

1. OCR workflow

OCR (Optical Character Recognition) converts printed or handwritten text in documents, PDFs, or images into editable, searchable text. The typical workflow consists of:

Image preprocessing – acquisition, binarization, denoising, rotation correction, segmentation.

Text detection – locating lines, words or character boundaries.

Feature extraction – extracting visual features for recognition.

Character recognition – matching features against known character patterns.

Post‑processing – proofreading, formatting and layout analysis.

2. Tesseract OCR and Tess4J

Tesseract OCR is an open‑source engine originally developed by HP and now maintained by Google. Tess4J is a Java wrapper for Tesseract that provides a simple API, cross‑platform support and access to all major Tesseract features, including multilingual recognition and custom training.

3. Download traineddata files

https://github.com/tesseract-ocr/tessdata

For Chinese use chi_sim.traineddata; for English use eng.traineddata. The file names (without the .traineddata suffix) are the language codes required by the Java API.

4. Integrate Tess4J into a Spring Boot project

4.1 Maven dependency

<dependency>
    <groupId>net.sourceforge.tess4j</groupId>
    <artifactId>tess4j</artifactId>
    <version>4.1.1</version>
</dependency>

4.2 Application properties (application.yml)

server:
  port: 11014

tess4j:
  data-path: F:/HeiMaTouTiao/tessdata
  chinese-train-data: chi_sim
  english-train-data: eng

4.3 Configuration class

import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Configuration;

@Configuration
@ConfigurationProperties(prefix = "tess4j")
public class Tess4jConfiguration {
    private String dataPath;
    private String chineseTrainData;
    private String englishTrainData;
    // getters and setters omitted for brevity
}

5. Test image recognition

5.1 Chinese

import cn.edu.scau.config.Tess4jConfiguration;
import net.sourceforge.tess4j.ITesseract;
import net.sourceforge.tess4j.Tesseract;
import net.sourceforge.tess4j.TesseractException;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import java.io.File;

@SpringBootTest
public class Tess4jApplicationTests {
    @Autowired
    private Tess4jConfiguration tess4jConfiguration;

    @Test
    public void testChinese() throws TesseractException {
        long start = System.currentTimeMillis();
        ITesseract iTesseract = new Tesseract();
        iTesseract.setDatapath(tess4jConfiguration.getDataPath());
        iTesseract.setLanguage(tess4jConfiguration.getChineseTrainData());
        File file = new File("F:/HeiMaTouTiao/tessdata/CaiXuKun-Chinese.png");
        String result = iTesseract.doOCR(file);
        long end = System.currentTimeMillis();
        System.err.println("耗时：" + (end - start) + "ms");
        System.out.println(result);
    }
}

5.2 English

@Test
public void testEnglish() throws TesseractException {
    long start = System.currentTimeMillis();
    ITesseract iTesseract = new Tesseract();
    iTesseract.setDatapath(tess4jConfiguration.getDataPath());
    iTesseract.setLanguage(tess4jConfiguration.getEnglishTrainData());
    File file = new File("F:/HeiMaTouTiao/tessdata/CaiXuKun-English.png");
    String result = iTesseract.doOCR(file);
    long end = System.currentTimeMillis();
    System.err.println("耗时：" + (end - start) + "ms");
    System.out.println(result);
}

5.3 Mixed Chinese‑English

When the image contains both Chinese and English, the Chinese language data must be used.

@Test
public void testChineseAndEnglish() throws TesseractException {
    long start = System.currentTimeMillis();
    ITesseract iTesseract = new Tesseract();
    iTesseract.setDatapath(tess4jConfiguration.getDataPath());
    iTesseract.setLanguage(tess4jConfiguration.getChineseTrainData());
    File file = new File("F:/HeiMaTouTiao/tessdata/ParagraphWithChineseAndEnglish.png");
    String result = iTesseract.doOCR(file);
    long end = System.currentTimeMillis();
    System.err.println("耗时：" + (end - start) + "ms");
    System.out.println(result);
}

6. Important notes

The traineddata files must retain the .traineddata suffix, and the filename prefix (e.g., chi_sim or eng) must match the language code supplied to setLanguage in the Java code.