springboot怎么生成条形码

在 Spring Boot 中生成条形码，可以使用第三方库 Zxing。以下是生成条形码的示例代码：

1. 添加依赖

在 pom.xml 文件中添加以下依赖：

<dependency>
   <groupId>com.google.zxing</groupId>
   <artifactId>core</artifactId>
   <version>3.3.0</version>
</dependency>
<dependency>
   <groupId>com.google.zxing</groupId>
   <artifactId>javase</artifactId>
   <version>3.3.0</version>
</dependency>

2. 编写生成条形码的代码

import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import javax.imageio.ImageIO;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.WriterException;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;

@Controller
@RequestMapping("/barcode")
public class BarcodeController {

    @GetMapping("/generate")
    @ResponseBody
    public String generateBarcode(@RequestParam("code") String code) {
        try {
            int width = 200;
            int height = 50;
            String format = "png";
            Map<EncodeHintType, Object> hints = new HashMap<>();
            hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
            hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.M);
            hints.put(EncodeHintType.MARGIN, 2);
            BitMatrix bitMatrix = new MultiFormatWriter().encode(code, BarcodeFormat.CODE_128, width, height, hints);
            BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
            for (int x = 0; x < width; x++) {
                for (int y = 0; y < height; y++) {
                    image.setRGB(x, y, bitMatrix.get(x, y) ? 0xFF000000 : 0xFFFFFFFF);
                }
            }
            File file = new File("barcode." + format);
            ImageIO.write(image, format, file);
            return "Barcode generated successfully!";
        } catch (WriterException | IOException e) {
            e.printStackTrace();
            return "Error generating barcode!";
        }
    }
}

3. 测试

启动 Spring Boot 应用，访问 http://localhost:8080/barcode/generate?code=123456，将会在项目根目录下生成名为 barcode.png 的条形码图片。

注意：本示例中生成的是 CODE_128 格式的条形码，你可以根据自己的需求选择不同的格式。