如何用Java实现二维码生成 Java二维码创建方法和工具

<dependency>
    <groupId>com.google.zxing</groupId>
    <artifactId>core</artifactId>
    <version>3.5.3</version>
</dependency>
<dependency>
    <groupId>com.google.zxing</groupId>
    <artifactId>javase</artifactId>
    <version>3.5.3</version>
</dependency>

import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.client.j2se.MatrixToImageWriter;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;

import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.File;
import java.nio.file.Path;
import java.util.HashMap;
import java.util.Map;

public class QRCodeGenerator {

    public static void generateQRCode(String content, int width, int height, String filePath) throws Exception {
        Map<EncodeHintType, Object> hints = new HashMap<>();
        // 设置编码字符集，非常重要，尤其是内容包含中文时
        hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
        // 设置二维码的纠错级别，L, M, Q, H，级别越高，容错能力越强，但二维码密度也越大
        hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
        // 设置二维码边距，白边
        hints.put(EncodeHintType.MARGIN, 2);

        try {
            BitMatrix bitMatrix = new MultiFormatWriter().encode(
                    content, BarcodeFormat.QR_CODE, width, height, hints
            );

            // 将位矩阵转换为BufferedImage
            BufferedImage image = MatrixToImageWriter.toBufferedImage(bitMatrix);

            // 保存为文件
            File outputFile = new File(filePath);
            ImageIO.write(image, "PNG", outputFile);
            System.out.println("二维码生成成功，保存至: " + filePath);

        } catch (Exception e) {
            System.err.println("生成二维码时发生错误: " + e.getMessage());
            throw e;
        }
    }

    public static void main(String[] args) {
        String content = "https://www.example.com/your-awesome-content?id=123&name=测试中文";
        int width = 300; // 宽度
        int height = 300; // 高度
        String filePath = "my_qrcode.png"; // 保存路径

        try {
            generateQRCode(content, width, height, filePath);
        } catch (Exception e) {
            // 处理异常
        }
    }
}

import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.client.j2se.MatrixToImageWriter;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletResponse;
import java.awt.image.BufferedImage;
import java.io.OutputStream;
import java.util.HashMap;
import java.util.Map;

@RestController
public class QRCodeController {

    @GetMapping(value = "/qrcode", produces = MediaType.IMAGE_PNG_VALUE)
    public void generateQrCodeImage(
            @RequestParam("content") String content,
            @RequestParam(defaultValue = "300") int width,
            @RequestParam(defaultValue = "300") int height,
            HttpServletResponse response) throws Exception {

        Map<EncodeHintType, Object> hints = new HashMap<>();
        hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
        hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
        hints.put(EncodeHintType.MARGIN, 2);

        try {
            BitMatrix bitMatrix = new MultiFormatWriter().encode(
                    content, BarcodeFormat.QR_CODE, width, height, hints
            );

            BufferedImage image = MatrixToImageWriter.toBufferedImage(bitMatrix);

            response.setContentType(MediaType.IMAGE_PNG_VALUE); // 设置响应类型
            OutputStream os = response.getOutputStream();
            ImageIO.write(image, "PNG", os); // 将图片写入输出流
            os.flush();
            os.close();

        } catch (Exception e) {
            // 实际项目中需要更完善的错误处理
            response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
            System.err.println("生成二维码时发生错误: " + e.getMessage());
            throw e; // 抛出异常让Spring处理或自定义异常
        }
    }
}