java生成二维码

1,该文中的部分代码来自gitee上的开源项目,我只是整理了一下,使其更加规范且通用。

1.1首先引入对应的工具包。

    
        com.google.zxing
        core
        3.3.3
    
    
        org.projectlombok
        lombok
        1.16.10
        provided
    
    
        com.google.zxing
        javase
        3.3.3
    

1.2 基础的图片生成类,没有时间研究,就照抄了

package com.nchu.common.core.utils.qrcode;

import com.google.zxing.LuminanceSource;

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


/**
 * @Author LiuLaoLao
 * @Date 2021/12/3 15:34
 * @Version 1.0
 */
public 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);
	}

}

1.3 二维码生成的工具类

/**
 * @Author LiuLaoLao
 * @Date 2021/12/3 15:34
 * @Version 1.0
 */
@Slf4j
public class QRCodeUtil {

    /**
     * 创建二维码
     * @param charSet 编码方式
     * @param content 二维码内容
     * @param qrWidth 二维码长度
     * @param qrHeight 二维码高度
     * @return
     */
    public static BufferedImage createImage(String charSet,String content,int qrWidth,int qrHeight){
        Hashtable hints = new Hashtable();
        hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
        hints.put(EncodeHintType.CHARACTER_SET, charSet);
        hints.put(EncodeHintType.MARGIN, 1);
        BitMatrix bitMatrix = null;
        try {
            bitMatrix = new MultiFormatWriter().encode(content, BarcodeFormat.QR_CODE,qrWidth , qrHeight, // 修改二维码底部高度
                    hints);
        } catch (WriterException e) {
            e.printStackTrace();
        }
        int width = bitMatrix.getWidth();
        int height = bitMatrix.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, bitMatrix.get(x, y) ? 0xFF000000 : 0xFFFFFFFF);
            }
        }
       return image;
    }

    /**
     * 对已经生成好的二维码设置logo
     * @param source 二维码
     * @param logo logo图片
     * @param logoWidth logo宽度
     * @param logoHeight logo高度
     */
    public static void insertLogoImage(BufferedImage source,Image logo,int logoWidth,int logoHeight){
        Graphics2D graph = source.createGraphics();
        int qrWidth = source.getWidth();
        int qrHeight = source.getHeight();
        int x = (qrWidth - logoWidth) / 2;
        int y = (qrHeight - logoHeight) / 2;
        graph.drawImage(logo, x, y, logoWidth, logoHeight, null);
        Shape shape = new RoundRectangle2D.Float(x, y, logoWidth, logoHeight, 6, 6);
        graph.setStroke(new BasicStroke(3f));
        graph.draw(shape);
        graph.dispose();
    }

    /**
     * 缩小logo图片
     * @param logoPath
     * @param logoWidth
     * @param logoHeight
     * @return
     */
    public static Image compressLogo(String logoPath, int logoWidth, int logoHeight){
        File file = new File(logoPath);
        if (!file.exists()) {
            System.err.println("" + logoPath + "   该文件不存在!");
            return null;
        }
        Image original = null;
        try {
            original = ImageIO.read(new File(logoPath));
        } catch (IOException e) {
            e.printStackTrace();
        }
        int width = original.getWidth(null);
        int height = original.getHeight(null);
            if (width > logoWidth) {
                width = logoWidth;
            }
            if (height > logoHeight) {
                height = logoHeight;
            }
            Image image = original.getScaledInstance(width, height, Image.SCALE_SMOOTH);
            BufferedImage tag = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
            Graphics g = tag.getGraphics();
            g.drawImage(image, 0, 0, null); // 绘制缩小后的图
            g.dispose();
        return image;
    }

    /**
     * 增加底部的说明文字
     * @param source 二维码
     * @param text 说明内容
     * @param step
     */
    public static BufferedImage addBottomFont(BufferedImage source, String text,int step) {

        int qrWidth = source.getWidth();
        log.debug("二维码的宽度{}",qrWidth);
        int qrHeight = source.getHeight();
        log.debug("二维码的高度{}",qrHeight);
        BufferedImage textImage = textToImage(text, qrWidth, 20,16);
        Graphics2D graph = source.createGraphics();
        //开启文字抗锯齿
        graph.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);

        int width = textImage.getWidth(null);
        int height = textImage.getHeight(null);

        Image src = textImage;
        graph.drawImage(src, 0, qrHeight - (20 * step) - 10, width, height, null);
        graph.dispose();
        return  source;
    }

    /**
     * 将文明说明增加到二维码上
     * @param str
     * @param width
     * @param height
     * @param fontSize 字体大小
     * @return
     */
    public static BufferedImage textToImage(String str, int width, int height,int fontSize) {
        BufferedImage textImage = new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);
        Graphics2D g2 = (Graphics2D)textImage.getGraphics();
        //开启文字抗锯齿
        g2.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
        g2.setBackground(Color.WHITE);
        g2.clearRect(0, 0, width, height);
        g2.setPaint(Color.BLACK);
        FontRenderContext context = g2.getFontRenderContext();
        Font font = new Font("微软雅黑", Font.BOLD, fontSize);
        g2.setFont(font);
        LineMetrics lineMetrics = font.getLineMetrics(str, context);
        FontMetrics fontMetrics = FontDesignMetrics.getMetrics(font);
        float offset = (width - fontMetrics.stringWidth(str)) / 2;
        float y = (height + lineMetrics.getAscent() - lineMetrics.getDescent() - lineMetrics.getLeading()) / 2;
        g2.drawString(str, (int)offset, (int)y);
        return textImage;
    }

    /**
     * 顶部增加说明文字
     * @param source
     * @param text
     * @param step
     */
    public static void addUpFont(BufferedImage source, String text) {
        int qrWidth = source.getWidth();
        int qrHeight = source.getHeight();

        BufferedImage textImage = textToImage(text, qrWidth, 30,24);
        Graphics2D graph = source.createGraphics();
        //开启文字抗锯齿
        graph.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);

        int width = textImage.getWidth(null);
        int height = textImage.getHeight(null);

        Image src = textImage;
        graph.drawImage(src, 0, 30, width, height, null);
        graph.dispose();
    }

    /**
     * 生成二维码图片
     * @param charSet 二维码编码方式
     * @param content 内容
     * @param qrWidth 宽度
     * @param qrHeight 长度
     * @param formatName jpg等图片格式
     * @param imgPath 二维码存放路径
     */
    public static void encode(String charSet,String content,int qrWidth,int qrHeight,String formatName,String imgPath){
        BufferedImage image = QRCodeUtil.createImage(charSet,content,qrWidth,qrHeight);
        try {
            ImageIO.write(image, formatName, new File(imgPath));
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * 生成二维码图片流
     * @param charSet 二维码编码方式
     * @param content 内容
     * @param qrWidth 宽度
     * @param qrHeight 长度
     * @return
     */
    public static BufferedImage encode(String charSet,String content,int qrWidth,int qrHeight) {
        BufferedImage image = QRCodeUtil.createImage(charSet,content,qrWidth,qrHeight);
        return image;
    }

    public static void encode( BufferedImage image,String formatName,String imgPath){
        try {

            ImageIO.write(image, formatName, new File(imgPath));
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public static void mkdirs(String destPath) {
        File file = new File(destPath);
        // 当文件夹不存在时,mkdirs会自动创建多层目录,区别于mkdir.(mkdir如果父目录不存在则会抛出异常)
        if (!file.exists() && !file.isDirectory()) {
            file.mkdirs();
        }
    }

    /*
     * 解析二维码
     */
    public static String decode(File file,String cherSet) throws Exception {
        BufferedImage image;
        image = ImageIO.read(file);
        if (image == null) {
            return null;
        }
        BufferedImageLuminanceSource source = new BufferedImageLuminanceSource(image);
        BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));
        Result result;
        Hashtable hints = new Hashtable();
        hints.put(DecodeHintType.CHARACTER_SET, cherSet);
        result = new MultiFormatReader().decode(bitmap, hints);
        String resultStr = result.getText();
        return resultStr;
    }
}

说明应该足够的清晰了吧,这个的主要实现还是别人的功劳,我只是优化

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