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Java二维码生成案例怎么实现

wen java案例 26

本文目录导读：

Java二维码生成案例怎么实现

  1. 方法一：使用ZXing库（推荐）
  2. 方法二：带Logo的二维码
  3. 方法三：使用qrcode库
  4. 方法四：Web接口生成二维码
  5. 二维码转Base64（用于前端展示）
  6. 使用示例
  7. 注意事项

我来介绍几种Java生成二维码的常用实现方法：

使用ZXing库（推荐）

添加Maven依赖

<dependency>
    <groupId>com.google.zxing</groupId>
    <artifactId>core</artifactId>
    <version>3.5.1</version>
</dependency>
<dependency>
    <groupId>com.google.zxing</groupId>
    <artifactId>javase</artifactId>
    <version>3.5.1</version>
</dependency>

基本二维码生成代码

import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.client.j2se.MatrixToImageWriter;
import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.OutputStream;
import java.util.HashMap;
import java.util.Map;
public class QRCodeGenerator {
    /**
     * 生成二维码到文件
     */
    public static void generateQRCodeToFile(String content, String filePath, 
                                           int width, int height) throws Exception {
        // 设置二维码参数
        Map<EncodeHintType, Object> hints = new HashMap<>();
        hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
        hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H); // 纠错等级
        hints.put(EncodeHintType.MARGIN, 1); // 边距
        // 生成二维码矩阵
        MultiFormatWriter writer = new MultiFormatWriter();
        BitMatrix bitMatrix = writer.encode(content, BarcodeFormat.QR_CODE, width, height, hints);
        // 写入文件
        File outputFile = new File(filePath);
        MatrixToImageWriter.writeToPath(bitMatrix, "png", outputFile.toPath());
    }
    /**
     * 生成二维码到输出流
     */
    public static void generateQRCodeToStream(String content, OutputStream outputStream,
                                             int width, int height) 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, 1);
        MultiFormatWriter writer = new MultiFormatWriter();
        BitMatrix bitMatrix = writer.encode(content, BarcodeFormat.QR_CODE, width, height, hints);
        MatrixToImageWriter.writeToStream(bitMatrix, "png", outputStream);
    }
    /**
     * 生成二维码为BufferedImage
     */
    public static BufferedImage generateQRCodeImage(String content, int width, int height) 
            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, 1);
        MultiFormatWriter writer = new MultiFormatWriter();
        BitMatrix bitMatrix = writer.encode(content, BarcodeFormat.QR_CODE, width, height, hints);
        return MatrixToImageWriter.toBufferedImage(bitMatrix);
    }
}

带Logo的二维码

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.geom.RoundRectangle2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.net.URL;
public class QRCodeWithLogoGenerator {
    /**
     * 生成带Logo的二维码
     */
    public static BufferedImage generateQRCodeWithLogo(String content, String logoPath,
                                                      int width, int height) throws Exception {
        // 先生成普通二维码
        BufferedImage qrImage = QRCodeGenerator.generateQRCodeImage(content, width, height);
        // 读取Logo图片
        BufferedImage logoImage;
        if (logoPath.startsWith("http")) {
            logoImage = ImageIO.read(new URL(logoPath));
        } else {
            logoImage = ImageIO.read(new File(logoPath));
        }
        // 计算Logo大小（二维码的20%）
        int logoSize = Math.min(width, height) / 5;
        int logoX = (width - logoSize) / 2;
        int logoY = (height - logoSize) / 2;
        // 创建画板
        Graphics2D graphics = qrImage.createGraphics();
        // 绘制Logo背景（白色圆角矩形）
        graphics.setComposite(AlphaComposite.SrcOver);
        graphics.setRenderingHint(RenderingHints.KEY_ANTIALIASING, 
                                  RenderingHints.VALUE_ANTIALIAS_ON);
        graphics.setColor(Color.WHITE);
        graphics.fillRoundRect(logoX - 2, logoY - 2, logoSize + 4, logoSize + 4, 15, 15);
        // 绘制Logo
        graphics.drawImage(logoImage, logoX, logoY, logoSize, logoSize, null);
        // 绘制Logo边框
        graphics.setColor(Color.LIGHT_GRAY);
        graphics.drawRoundRect(logoX - 2, logoY - 2, logoSize + 4, logoSize + 4, 15, 15);
        graphics.dispose();
        qrImage.flush();
        return qrImage;
    }
}

使用qrcode库

添加依赖

<dependency>
    <groupId>com.google.zxing</groupId>
    <artifactId>qrcode</artifactId>
    <version>3.5.1</version>
</dependency>

简单实现

import com.google.zxing.qrcode.QRCodeWriter;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
public class SimpleQRCodeGenerator {
    public static void main(String[] args) {
        try {
            String content = "https://www.example.com";
            String filePath = "qrcode.png";
            // 生成二维码
            QRCodeGenerator.generateQRCodeToFile(content, filePath, 300, 300);
            System.out.println("二维码生成成功：" + filePath);
            // 生成带Logo的二维码
            BufferedImage qrWithLogo = QRCodeWithLogoGenerator.generateQRCodeWithLogo(
                content, "logo.png", 300, 300
            );
            ImageIO.write(qrWithLogo, "png", new File("qrcode_with_logo.png"));
            System.out.println("带Logo的二维码生成成功");
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

Web接口生成二维码

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import javax.servlet.http.HttpServletResponse;
@RestController
public class QRCodeController {
    @GetMapping("/generateQRCode")
    public void generateQRCode(@RequestParam String content,
                              @RequestParam(defaultValue = "300") int width,
                              @RequestParam(defaultValue = "300") int height,
                              HttpServletResponse response) {
        try {
            response.setContentType("image/png");
            QRCodeGenerator.generateQRCodeToStream(content, response.getOutputStream(), 
                                                     width, height);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

二维码转Base64（用于前端展示）

import java.util.Base64;
import javax.imageio.ImageIO;
import java.io.ByteArrayOutputStream;
public class QRCodeToBase64 {
    public static String generateQRCodeBase64(String content, int width, int height) 
            throws Exception {
        BufferedImage qrImage = QRCodeGenerator.generateQRCodeImage(content, width, height);
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        ImageIO.write(qrImage, "png", baos);
        byte[] imageBytes = baos.toByteArray();
        return Base64.getEncoder().encodeToString(imageBytes);
    }
}

使用示例

public class Main {
    public static void main(String[] args) {
        try {
            // 1. 基本二维码
            QRCodeGenerator.generateQRCodeToFile(
                "https://www.example.com", 
                "output/basic_qrcode.png", 
                300, 300
            );
            // 2. 带Logo二维码
            BufferedImage logoQR = QRCodeWithLogoGenerator.generateQRCodeWithLogo(
                "https://www.example.com",
                "logo.png",
                300, 300
            );
            ImageIO.write(logoQR, "png", new File("output/logo_qrcode.png"));
            // 3. 生成Base64
            String base64 = QRCodeToBase64.generateQRCodeBase64(
                "Hello World", 200, 200
            );
            System.out.println("Base64: " + base64);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

注意事项

  1. 字符编码：一定要设置UTF-8编码，避免中文乱码
  2. 纠错等级：建议使用H级（最高），可以包含更多信息但二维码会更复杂
  3. 大小设置：根据实际应用场景设置合适的尺寸
  4. Logo大小：Logo过大会影响二维码识别，建议不超过二维码的20%
  5. 性能优化：频繁生成二维码时可以考虑缓存机制

这些代码可以直接复制使用,根据你的具体需求选择合适的实现方式。

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