add QrSVG

hutool-extra/src/main/java/cn/hutool/extra/qrcode/QrConfig.java

@@ -30,7 +30,7 @@ public class QrConfig {
 	/** 高度 */
 	protected int height;
 	/** 前景色（二维码颜色） */
-	protected int foreColor = BLACK;
+	protected Integer foreColor = BLACK;
 	/** 背景色，默认白色，null表示透明 */
 	protected Integer backColor = WHITE;
 	/** 边距0~4 */
@@ -134,7 +134,9 @@ public class QrConfig {
 	 * @since 5.1.1
 	 */
 	public QrConfig setForeColor(final Color foreColor) {
-		if(null != foreColor){
+		if(null == foreColor){
+			this.foreColor = null;
+		} else {
 			this.foreColor = foreColor.getRGB();
 		}
 		return this;

hutool-extra/src/main/java/cn/hutool/extra/qrcode/QrSVG.java

@@ -0,0 +1,85 @@
+package cn.hutool.extra.qrcode;
+
+import cn.hutool.core.text.StrUtil;
+import cn.hutool.swing.img.ImgUtil;
+import com.google.zxing.common.BitMatrix;
+
+import java.awt.Color;
+import java.awt.Image;
+
+/**
+ * 二维码的SVG表示
+ *
+ * @author Tom Xin
+ */
+public class QrSVG {
+
+	private final BitMatrix matrix;
+	private final QrConfig qrConfig;
+
+	public QrSVG(BitMatrix matrix, QrConfig qrConfig) {
+		this.matrix = matrix;
+		this.qrConfig = qrConfig;
+	}
+
+	@Override
+	public String toString() {
+		final Image logoImg = qrConfig.img;
+		final Integer foreColor = qrConfig.foreColor;
+		final Integer backColor = qrConfig.backColor;
+		final int ratio = qrConfig.ratio;
+
+		final StringBuilder sb = new StringBuilder();
+		int qrWidth = matrix.getWidth();
+		int qrHeight = matrix.getHeight();
+		int moduleHeight = (qrHeight == 1) ? qrWidth / 2 : 1;
+		for (int y = 0; y < qrHeight; y++) {
+			for (int x = 0; x < qrWidth; x++) {
+				if (matrix.get(x, y)) {
+					sb.append(" M").append(x).append(",").append(y).append("h1v").append(moduleHeight).append("h-1z");
+				}
+			}
+		}
+		qrHeight *= moduleHeight;
+		String logoBase64 = "";
+		int logoWidth = 0;
+		int logoHeight = 0;
+		int logoX = 0;
+		int logoY = 0;
+		if (logoImg != null) {
+			logoBase64 = ImgUtil.toBase64DataUri(logoImg, "png");
+			// 按照最短的边做比例缩放
+			if (qrWidth < qrHeight) {
+				logoWidth = qrWidth / ratio;
+				logoHeight = logoImg.getHeight(null) * logoWidth / logoImg.getWidth(null);
+			} else {
+				logoHeight = qrHeight / ratio;
+				logoWidth = logoImg.getWidth(null) * logoHeight / logoImg.getHeight(null);
+			}
+			logoX = (qrWidth - logoWidth) / 2;
+			logoY = (qrHeight - logoHeight) / 2;
+
+		}
+
+		StringBuilder result = StrUtil.builder();
+		result.append("<svg width=\"").append(qrWidth).append("\" height=\"").append(qrHeight).append("\" \n");
+		if (backColor != null) {
+			Color back = new Color(backColor, true);
+			result.append("style=\"background-color:rgba(").append(back.getRed()).append(",").append(back.getGreen()).append(",").append(back.getBlue()).append(",").append(back.getAlpha()).append(")\"\n");
+		}
+		result.append("viewBox=\"0 0 ").append(qrWidth).append(" ").append(qrHeight).append("\" \n");
+		result.append("xmlns=\"http://www.w3.org/2000/svg\" \n");
+		result.append("xmlns:xlink=\"http://www.w3.org/1999/xlink\" >\n");
+		result.append("<path d=\"").append(sb).append("\" ");
+		if (foreColor != null) {
+			Color fore = new Color(foreColor, true);
+			result.append("stroke=\"rgba(").append(fore.getRed()).append(",").append(fore.getGreen()).append(",").append(fore.getBlue()).append(",").append(fore.getAlpha()).append(")\"");
+		}
+		result.append(" /> \n");
+		if (StrUtil.isNotBlank(logoBase64)) {
+			result.append("<image xlink:href=\"").append(logoBase64).append("\" height=\"").append(logoHeight).append("\" width=\"").append(logoWidth).append("\" y=\"").append(logoY).append("\" x=\"").append(logoX).append("\" />\n");
+		}
+		result.append("</svg>");
+		return result.toString();
+	}
+}