Java生成二维码工具类

1. MatrixToImageWriter 谷歌提供

import com.google.zxing.common.BitMatrix;

import javax.imageio.ImageIO;
import java.io.File;
import java.io.OutputStream;
import java.io.IOException;
import java.awt.image.BufferedImage;

/**
 *  用于二维码的生成，由Google提供。
 *
 * Created by Eric on 2017/2/15.
 */
public final class MatrixToImageWriter {

    private static final int BLACK = 0xFF000000;
    private static final int WHITE = 0xFFFFFFFF;

    private MatrixToImageWriter() {
    }


    public static BufferedImage toBufferedImage(BitMatrix matrix) {
        int width = matrix.getWidth();
        int height = matrix.getHeight();
        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, matrix.get(x, y) ? BLACK : WHITE);
            }
        }
        return image;
    }


    public static void writeToFile(BitMatrix matrix, String format, File file)
            throws IOException {
        BufferedImage image = toBufferedImage(matrix);
        if (!ImageIO.write(image, format, file)) {
            throw new IOException("Could not write an image of format " + format + " to " + file);
        }
    }


    public static void writeToStream(BitMatrix matrix, String format, OutputStream stream)
            throws IOException {
        BufferedImage image = toBufferedImage(matrix);
        if (!ImageIO.write(image, format, stream)) {
            throw new IOException("Could not write an image of format " + format);
        }
    }
}

2. BufferedImageLuminanceSource 谷歌提供

import com.google.zxing.LuminanceSource;

import java.awt.Graphics2D;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;

/**
 * 用于二维码的解析，由Google提供。
 *
 * Created by Eric on 2017/2/15.
 */
public final class BufferedImageLuminanceSource extends LuminanceSource {

    private final BufferedImage image;
    private final int left;
    private final int top;

    public BufferedImageLuminanceSource(BufferedImage image) {
        this(image, 0, 0, image.getWidth(), image.getHeight());
    }

    public BufferedImageLuminanceSource(BufferedImage image, int left, int top, int width, int height) {
        super(width, height);

        int sourceWidth = image.getWidth();
        int sourceHeight = image.getHeight();
        if (left + width > sourceWidth || top + height > sourceHeight) {
            throw new IllegalArgumentException("Crop rectangle does not fit within image data.");
        }

        for (int y = top; y < top + height; y++) {
            for (int x = left; x < left + width; x++) {
                if ((image.getRGB(x, y) & 0xFF000000) == 0) {
                    image.setRGB(x, y, 0xFFFFFFFF); // = white
                }
            }
        }

        this.image = new BufferedImage(sourceWidth, sourceHeight, BufferedImage.TYPE_BYTE_GRAY);
        this.image.getGraphics().drawImage(image, 0, 0, null);
        this.left = left;
        this.top = top;
    }

    @Override
    public byte[] getRow(int y, byte[] row) {
        if (y < 0 || y >= getHeight()) {
            throw new IllegalArgumentException("Requested row is outside the image: " + y);
        }
        int width = getWidth();
        if (row == null || row.length < width) {
            row = new byte[width];
        }
        image.getRaster().getDataElements(left, top + y, width, 1, row);
        return row;
    }

    @Override
    public byte[] getMatrix() {
        int width = getWidth();
        int height = getHeight();
        int area = width * height;
        byte[] matrix = new byte[area];
        image.getRaster().getDataElements(left, top, width, height, matrix);
        return matrix;
    }

    @Override
    public boolean isCropSupported() {
        return true;
    }

    @Override
    public LuminanceSource crop(int left, int top, int width, int height) {
        return new BufferedImageLuminanceSource(image, this.left + left, this.top + top, width, height);
    }

    @Override
    public boolean isRotateSupported() {
        return true;
    }

    @Override
    public LuminanceSource rotateCounterClockwise() {

        int sourceWidth = image.getWidth();
        int sourceHeight = image.getHeight();

        AffineTransform transform = new AffineTransform(0.0, -1.0, 1.0, 0.0, 0.0, sourceWidth);

        BufferedImage rotatedImage = new BufferedImage(sourceHeight, sourceWidth, BufferedImage.TYPE_BYTE_GRAY);

        Graphics2D g = rotatedImage.createGraphics();
        g.drawImage(image, transform, null);
        g.dispose();

        int width = getWidth();
        return new BufferedImageLuminanceSource(rotatedImage, top, sourceWidth - (left + width), getHeight(), width);
    }

}

3. QRCodeUtil 生成二维码工具类

import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.common.BitMatrix;

import java.io.File;
import java.util.Hashtable;

public class QRCodeUtil {
    // 二维码宽度
    private static Integer width = 400;
    // 二维码高度
    private static Integer height = 400;
    // 获取二维码 fileName图片路径，如"E:/temp/images"
    public static String getQRCoder(String text,String fileName){
        try {
            Hashtable<EncodeHintType, Object> hints = new Hashtable<>();
            hints.put(EncodeHintType.CHARACTER_SET, "utf-8");
            BitMatrix bitMatrix = new MultiFormatWriter().encode(text, BarcodeFormat.QR_CODE, width, height, hints);
            File outputFile = new File(fileName);
            MatrixToImageWriter.writeToFile(bitMatrix, "png", outputFile);
            return "已生成商户二维码";
        } catch (Exception e) {
            e.printStackTrace();
        }
        return "商户二维码生成失败";
    }
}