在Spring Boot项目中整合ZXing库来生成条形码在特定行业也是一个常见需求。

ZXing是google开源的一个功能强大的Java库，专门用于二维码/条形码等的生成与解析。它不仅能够生成QR码/条形码，还能解析包括QR码/条形码在内的多种格式.

1. 添加zxing的依赖

<dependency>
    <groupId>com.google.zxing</groupId>
    <artifactId>core</artifactId>
    <version>3.5.2</version>
</dependency>
<dependency>
    <groupId>com.google.zxing</groupId>
    <artifactId>javase</artifactId>
    <version>3.5.2</version>
</dependency>

2. 生成条形码

import com.google.zxing.BarcodeFormat;
import com.google.zxing.WriterException;
import com.google.zxing.client.j2se.MatrixToImageWriter;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.oned.Code128Writer;
import org.springframework.stereotype.Service;


import java.io.IOException;
import java.nio.file.FileSystems;
import java.nio.file.Path;


@Service
public class BarcodeService {


    /**
     * 生成条形码并保存到指定路径
     * @param content 条形码内容
     * @param path 保存路径
     * @param width 条形码宽度
     * @param height 条形码高度
     */
    public void generateBarcodeImage(String content, String path, int width, int height) {
        Code128Writer barcodeWriter = new Code128Writer();
        BitMatrix bitMatrix = null;
        try {
            bitMatrix = barcodeWriter.encode(content, BarcodeFormat.CODE_128, width, height);
            Path filePath = FileSystems.getDefault().getPath(path);
            MatrixToImageWriter.writeToPath(bitMatrix, "PNG", filePath);
        } catch (WriterException | IOException e) {
            e.printStackTrace();
        }
    }
}

3. 调用条形码服务

最后，在Spring Boot的中调用这个服务生成条形码：

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;


@RestController
public class BarcodeController {


    @Autowired
    private BarcodeService barcodeService;


    @GetMapping("/generate-barcode")
    public String generateBarcode(@RequestParam String content, @RequestParam String path, @RequestParam int width, @RequestParam int height) {
        barcodeService.generateBarcodeImage(content, path, width, height);
        return "Barcode generated successfully at " + path;
    }
}

现在，当访问/generate-barcode端点并传递相应的参数时，将生成一个条形码并将其保存到指定的路径。如：

http://localhost:8080/generate-barcode?content=123456789&path=/path/to/barcode.png&width=300&height=100

这将生成一个内容为123456789、宽度为300像素、高度为100像素的条形码，并将其保存到/path/to/barcode.png路径下。

4. 返回条形码

如果需要将条形码直接返回,简单修改一下就好。

先修改BarcodeService以返回一个byte[]数组：

import com.google.zxing.*;
import com.google.zxing.client.j2se.MatrixToImageConfig;
import com.google.zxing.client.j2se.MatrixToImageWriter;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.oned.Code128Writer;
import org.springframework.stereotype.Service;


import java.io.ByteArrayOutputStream;
import java.io.IOException;


@Service
public class BarcodeService {


    /**
     * 生成条形码的字节数据
     * @param content 条形码内容
     * @param width 条形码宽度
     * @param height 条形码高度
     * @return 条形码的字节数据
     */
    public byte[] generateBarcodeImage(String content, int width, int height) {
        Code128Writer barcodeWriter = new Code128Writer();
        BitMatrix bitMatrix = null;
        try {
            bitMatrix = barcodeWriter.encode(content, BarcodeFormat.CODE_128, width, height);
            ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
            MatrixToImageConfig config = new MatrixToImageConfig(MatrixToImageConfig.BLACK, MatrixToImageConfig.WHITE);
            MatrixToImageWriter.writeToStream(bitMatrix, "PNG", outputStream, config);
            return outputStream.toByteArray();
        } catch (WriterException | IOException e) {
            e.printStackTrace();
            return null;
        }
    }
}

然后，修改BarcodeController以返回图片的字节数据：

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;


@RestController
public class BarcodeController {


    @Autowired
    private BarcodeService barcodeService;


    @GetMapping("/generate-barcode")
    public ResponseEntity<byte[]> generateBarcode(@RequestParam String content, @RequestParam int width, @RequestParam int height) {
        byte[] barcodeImage = barcodeService.generateBarcodeImage(content, width, height);
        if (barcodeImage != null) {
            HttpHeaders headers = new HttpHeaders();
            headers.setContentType(MediaType.IMAGE_PNG);
            return new ResponseEntity<>(barcodeImage, headers, HttpStatus.OK);
        } else {
            return new ResponseEntity<>(null, HttpStatus.INTERNAL_SERVER_ERROR);
        }
    }
}

现在，当访问/generate-barcode端点并传递相应的参数时，它将生成一个条形码并将其作为PNG图片的字节数据返回。