Java实现生成加密后的二维码和解析扫码后的密文

为了实现一个用Java生成和解析二维码的代码，并包含加密和解密步骤，我们可以使用ZXing库来处理二维码的生成和解析，使用AES加密算法来加密和解密数据。以下是完整的示例代码：

Java生成和解析二维码，包含加解密

1. 添加依赖

如果使用Maven进行项目管理，首先在pom.xml中添加ZXing库的依赖：

<dependency>
    <groupId>com.google.zxing</groupId>
    <artifactId>core</artifactId>
    <version>3.4.1</version>
</dependency>
<dependency>
    <groupId>com.google.zxing</groupId>
    <artifactId>javase</artifactId>
    <version>3.4.1</version>
</dependency>

2. AES加密和解密

import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import java.util.Base64;

public class AESUtil {

    private static final String ALGORITHM = "AES";

    public static String encrypt(String data, String key) throws Exception {
        SecretKeySpec secretKeySpec = new SecretKeySpec(key.getBytes(), ALGORITHM);
        Cipher cipher = Cipher.getInstance(ALGORITHM);
        cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec);
        byte[] encryptedData = cipher.doFinal(data.getBytes("UTF-8"));
        return Base64.getEncoder().encodeToString(encryptedData);
    }

    public static String decrypt(String encryptedData, String key) throws Exception {
        SecretKeySpec secretKeySpec = new SecretKeySpec(key.getBytes(), ALGORITHM);
        Cipher cipher = Cipher.getInstance(ALGORITHM);
        cipher.init(Cipher.DECRYPT_MODE, secretKeySpec);
        byte[] decodedData = Base64.getDecoder().decode(encryptedData);
        byte[] decryptedData = cipher.doFinal(decodedData);
        return new String(decryptedData, "UTF-8");
    }
}

3. 生成二维码

import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.WriterException;
import com.google.zxing.client.j2se.MatrixToImageWriter;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.qrcode.QRCodeWriter;

import java.io.IOException;
import java.nio.file.FileSystems;
import java.nio.file.Path;
import java.util.HashMap;
import java.util.Map;

public class QRCodeGenerator {

    public static void generateQRCode(String data, String filePath) throws WriterException, IOException {
        QRCodeWriter qrCodeWriter = new QRCodeWriter();
        Map<EncodeHintType, Object> hints = new HashMap<>();
        hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");

        BitMatrix bitMatrix = qrCodeWriter.encode(data, BarcodeFormat.QR_CODE, 300, 300, hints);
        Path path = FileSystems.getDefault().getPath(filePath);
        MatrixToImageWriter.writeToPath(bitMatrix, "PNG", path);
        System.out.println("二维码已生成并保存到 " + filePath);
    }
}

4. 解析二维码

import com.google.zxing.*;
import com.google.zxing.client.j2se.BufferedImageLuminanceSource;
import com.google.zxing.common.HybridBinarizer;

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

public class QRCodeReader {

    public static String readQRCode(String filePath) throws Exception {
        BufferedImage bufferedImage = ImageIO.read(new File(filePath));
        LuminanceSource source = new BufferedImageLuminanceSource(bufferedImage);
        BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));

        Map<DecodeHintType, Object> hints = new HashMap<>();
        hints.put(DecodeHintType.CHARACTER_SET, "UTF-8");

        Result result = new MultiFormatReader().decode(bitmap, hints);
        return result.getText();
    }
}

5. 主程序

public class Main {
    public static void main(String[] args) {
        try {
            String originalData = "Hello, World!";
            String key = "1234567890123456"; // 16-byte key for AES-128

            // 加密数据
            String encryptedData = AESUtil.encrypt(originalData, key);
            System.out.println("加密后的数据: " + encryptedData);

            // 生成二维码
            String filePath = "encrypted_qrcode.png";
            QRCodeGenerator.generateQRCode(encryptedData, filePath);

            // 解析二维码（模拟扫码）
            String readData = QRCodeReader.readQRCode(filePath);
            System.out.println("从二维码读取的数据: " + readData);

            // 解密数据
            String decryptedData = AESUtil.decrypt(readData, key);
            System.out.println("解密后的数据: " + decryptedData);

        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}