涉及两方面的知识:
1.QR code的基础,参见大牛的作品http://coolshell.cn/articles/10590.html
2.java图形库image、Graphics2D等
基本思路是先使用zxing生成的二维码图片,然后读取图片,在其中插入图标,然后整个输出图片。
网上还看到另外一种做法,先生成二维码图片,然后把图标直接覆盖在二维码上,这样会丢失一部分数据,但是由于二维码的纠错能力,扫描器能够把丢失的信息找回来。
废话不说,直接上代码:
/** * */ package barcode; import java.awt.Color; import java.awt.Graphics2D; import java.awt.Image; import java.awt.geom.AffineTransform; import java.awt.image.AffineTransformOp; import java.awt.image.BufferedImage; import java.io.File; import java.io.IOException; import java.util.HashMap; import java.util.Map; import javax.imageio.ImageIO; import com.google.zxing.BarcodeFormat; import com.google.zxing.EncodeHintType; import com.google.zxing.MultiFormatWriter; import com.google.zxing.WriterException; import com.google.zxing.common.BitMatrix; import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel; /** * @author lichunxi * */ public class BarcodeFactory { // 图片宽度的一般 private static final int IMAGE_WIDTH = 80; private static final int IMAGE_HEIGHT = 80; private static final int IMAGE_HALF_WIDTH = IMAGE_WIDTH / 2; private static final int FRAME_WIDTH = 2; // 二维码写码器 private static MultiFormatWriter mutiWriter = new MultiFormatWriter(); public static void encode(String content, int width, int height, String srcImagePath, String destImagePath) { try { ImageIO.write(genBarcode(content, width, height, srcImagePath), "jpg", new File(destImagePath)); } catch (IOException e) { e.printStackTrace(); } catch (WriterException e) { e.printStackTrace(); } } private static BufferedImage genBarcode(String content, int width, int height, String srcImagePath) throws WriterException, IOException { // 读取源图像 BufferedImage scaleImage = scale(srcImagePath, IMAGE_WIDTH, IMAGE_HEIGHT, true); int[][] srcPixels = new int[IMAGE_WIDTH][IMAGE_HEIGHT]; for (int i = 0; i < scaleImage.getWidth(); i++) { for (int j = 0; j < scaleImage.getHeight(); j++) { srcPixels[i][j] = scaleImage.getRGB(i, j); } } Map<EncodeHintType, Object> hint = new HashMap<EncodeHintType, Object>(); hint.put(EncodeHintType.CHARACTER_SET, "utf-8"); hint.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H); // 生成二维码 BitMatrix matrix = mutiWriter.encode(content, BarcodeFormat.QR_CODE, width, height, hint); // 二维矩阵转为一维像素数组 int halfW = matrix.getWidth() / 2; int halfH = matrix.getHeight() / 2; int[] pixels = new int[width * height]; for (int y = 0; y < matrix.getHeight(); y++) { for (int x = 0; x < matrix.getWidth(); x++) { // 读取图片 if (x > halfW - IMAGE_HALF_WIDTH && x < halfW + IMAGE_HALF_WIDTH && y > halfH - IMAGE_HALF_WIDTH && y < halfH + IMAGE_HALF_WIDTH) { pixels[y * width + x] = srcPixels[x - halfW + IMAGE_HALF_WIDTH][y - halfH + IMAGE_HALF_WIDTH]; } // 在图片四周形成边框 else if ((x > halfW - IMAGE_HALF_WIDTH - FRAME_WIDTH && x < halfW - IMAGE_HALF_WIDTH + FRAME_WIDTH && y > halfH - IMAGE_HALF_WIDTH - FRAME_WIDTH && y < halfH + IMAGE_HALF_WIDTH + FRAME_WIDTH) || (x > halfW + IMAGE_HALF_WIDTH - FRAME_WIDTH && x < halfW + IMAGE_HALF_WIDTH + FRAME_WIDTH && y > halfH - IMAGE_HALF_WIDTH - FRAME_WIDTH && y < halfH + IMAGE_HALF_WIDTH + FRAME_WIDTH) || (x > halfW - IMAGE_HALF_WIDTH - FRAME_WIDTH && x < halfW + IMAGE_HALF_WIDTH + FRAME_WIDTH && y > halfH - IMAGE_HALF_WIDTH - FRAME_WIDTH && y < halfH - IMAGE_HALF_WIDTH + FRAME_WIDTH) || (x > halfW - IMAGE_HALF_WIDTH - FRAME_WIDTH && x < halfW + IMAGE_HALF_WIDTH + FRAME_WIDTH && y > halfH + IMAGE_HALF_WIDTH - FRAME_WIDTH && y < halfH + IMAGE_HALF_WIDTH + FRAME_WIDTH)) { pixels[y * width + x] = 0xfffffff; } else { // 此处可以修改二维码的颜色,可以分别制定二维码和背景的颜色; pixels[y * width + x] = matrix.get(x, y) ? 0xff000000 : 0xfffffff; } } } BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); image.getRaster().setDataElements(0, 0, width, height, pixels); return image; } /** * 把传入的原始图像按高度和宽度进行缩放,生成符合要求的图标 * * @param srcImageFile * 源文件地址 * @param height * 目标高度 * @param width * 目标宽度 * @param hasFiller * 比例不对时是否需要补白:true为补白; false为不补白; * @throws IOException */ private static BufferedImage scale(String srcImageFile, int height, int width, boolean hasFiller) throws IOException { double ratio = 0.0; // 缩放比例 File file = new File(srcImageFile); BufferedImage srcImage = ImageIO.read(file); Image destImage = srcImage.getScaledInstance(width, height, BufferedImage.SCALE_SMOOTH); // 计算比例 if ((srcImage.getHeight() > height) || (srcImage.getWidth() > width)) { if (srcImage.getHeight() > srcImage.getWidth()) { ratio = (new Integer(height)).doubleValue() / srcImage.getHeight(); } else { ratio = (new Integer(width)).doubleValue() / srcImage.getWidth(); } AffineTransformOp op = new AffineTransformOp( AffineTransform.getScaleInstance(ratio, ratio), null); destImage = op.filter(srcImage, null); } if (hasFiller) {// 补白 BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); Graphics2D graphic = image.createGraphics(); graphic.setColor(Color.white); graphic.fillRect(0, 0, width, height); if (width == destImage.getWidth(null)) graphic.drawImage(destImage, 0, (height - destImage.getHeight(null)) / 2, destImage.getWidth(null), destImage.getHeight(null), Color.white, null); else graphic.drawImage(destImage, (width - destImage.getWidth(null)) / 2, 0, destImage.getWidth(null), destImage.getHeight(null), Color.white, null); graphic.dispose(); destImage = image; } return (BufferedImage) destImage; } public static void main(String[] args) { BarcodeFactory .encode("http://coolshell.cn/articles/10590.html", 300, 300, "F:\\2013.jpg", "F:\\2013-01.jpg"); } }
依赖的jar包:
<dependency> <groupId>com.google.zxing</groupId> <artifactId>core</artifactId> <version>2.2</version> </dependency>