How to Integrate Tess4j OCR into a Spring Boot 3 Application

What is Tess4j

OCR

Optical Character Recognition (OCR) converts printed, handwritten, or image‑based text into editable and searchable digital formats.

Tesseract OCR

Tesseract is an open‑source OCR engine originally developed by HP and now maintained by Google. It is one of the most accurate and widely used OCR tools.

Tess4j

Tess4j is a Java wrapper for the Tesseract engine, providing a simple API for Java applications to perform OCR.

Easy integration : Simple API for Java projects.

Cross‑platform : Runs on any OS that supports Java (Windows, macOS, Linux).

Rich functionality : Supports all major Tesseract features such as multi‑language recognition and custom training.

Active community : Ongoing support and updates from the open‑source community.

Download language data files

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

Download chi_sim.traineddata for Chinese and eng.traineddata for English. Place the files in a directory referenced by the application, for example F:/HeiMaTouTiao/tessdata.

Integrate Tess4j into a Spring Boot project

Add Maven dependency

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

Configure application.yml

server:
  port: 11014

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

Create 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;

    public String getDataPath() { return dataPath; }
    public void setDataPath(String dataPath) { this.dataPath = dataPath; }
    public String getChineseTrainData() { return chineseTrainData; }
    public void setChineseTrainData(String chineseTrainData) { this.chineseTrainData = chineseTrainData; }
    public String getEnglishTrainData() { return englishTrainData; }
    public void setEnglishTrainData(String englishTrainData) { this.englishTrainData = englishTrainData; }
}

Test image recognition

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("Time elapsed: " + (end - start) + "ms");
        System.out.println(result);
    }
}

Result: OCR on the Chinese image succeeds; execution time is logged.

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("Time elapsed: " + (end - start) + "ms");
    System.out.println(result);
}

Result: English OCR produces the expected text with similar performance.

Mixed Chinese and English

@Test
public void testChineseAndEnglish() throws TesseractException {
    long start = System.currentTimeMillis();
    ITesseract iTesseract = new Tesseract();
    iTesseract.setDatapath(tess4jConfiguration.getDataPath());
    // Use Chinese trained data for mixed content
    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("Time elapsed: " + (end - start) + "ms");
    System.out.println(result);
}

Result: When both languages appear, the Chinese trained data must be used to correctly recognize the mixed text.

Precautions

The language data files must have the .traineddata suffix, and the file name prefix (e.g., chi_sim, eng) must match the language identifier used in the Java code.