In Java version: moved QrCode.toSvgString() out of the library and into the runnable demo program, slightly adapted some code, updated documentation comments.

java/src/main/java/io/nayuki/qrcodegen/QrCode.java

@@ -284,40 +284,6 @@ public final class QrCode {
 	}
 	
 	
-	/**
-	 * Returns a string of SVG code for an image depicting this QR Code, with the specified number
-	 * of border modules. The string always uses Unix newlines (\n), regardless of the platform.
-	 * @param border the number of border modules to add, which must be non-negative
-	 * @return a string representing this QR Code as an SVG XML document
-	 * @throws IllegalArgumentException if the border is negative
-	 */
-	public String toSvgString(int border) {
-		if (border < 0)
-			throw new IllegalArgumentException("Border must be non-negative");
-		long brd = border;
-		StringBuilder sb = new StringBuilder()
-			.append("<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n")
-			.append("<!DOCTYPE svg PUBLIC \"-//W3C//DTD SVG 1.1//EN\" \"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd\">\n")
-			.append(String.format("<svg xmlns=\"http://www.w3.org/2000/svg\" version=\"1.1\" viewBox=\"0 0 %1$d %1$d\" stroke=\"none\">\n",
-				size + brd * 2))
-			.append("\t<rect width=\"100%\" height=\"100%\" fill=\"#FFFFFF\"/>\n")
-			.append("\t<path d=\"");
-		for (int y = 0; y < size; y++) {
-			for (int x = 0; x < size; x++) {
-				if (getModule(x, y)) {
-					if (x != 0 || y != 0)
-						sb.append(" ");
-					sb.append(String.format("M%d,%dh1v1h-1z", x + brd, y + brd));
-				}
-			}
-		}
-		return sb
-			.append("\" fill=\"#000000\"/>\n")
-			.append("</svg>\n")
-			.toString();
-	}
-	
-	
 	
 	/*---- Private helper methods for constructor: Drawing function modules ----*/
 	

java/src/main/java/io/nayuki/qrcodegen/QrCodeGeneratorDemo.java

@@ -62,7 +62,7 @@ public final class QrCodeGeneratorDemo {
 		File imgFile = new File("hello-world-QR.png");   // File path for output
 		ImageIO.write(img, "png", imgFile);              // Write image to file
 		
-		String svg = qr.toSvgString(4);                  // Convert to SVG XML code
+		String svg = toSvgString(qr, 4);                 // Convert to SVG XML code
 		File svgFile = new File("hello-world-QR.svg");   // File path for output
 		Files.write(svgFile.toPath(),                    // Write image to file
 			svg.getBytes(StandardCharsets.UTF_8));
@@ -204,4 +204,41 @@ public final class QrCodeGeneratorDemo {
 		ImageIO.write(img, "png", new File(filepath));
 	}
 	
+	
+	/**
+	 * Returns a string of SVG code for an image depicting the specified QR Code, with the specified
+	 * number of border modules. The string always uses Unix newlines (\n), regardless of the platform.
+	 * @param qr the QR Code to render (not {@code null})
+	 * @param border the number of border modules to add, which must be non-negative
+	 * @return a string representing the QR Code as an SVG XML document
+	 * @throws NullPointerException if the QR Code is {@code null}
+	 * @throws IllegalArgumentException if the border is negative
+	 */
+	private static String toSvgString(QrCode qr, int border) {
+		Objects.requireNonNull(qr);
+		if (border < 0)
+			throw new IllegalArgumentException("Border must be non-negative");
+		long brd = border;
+		StringBuilder sb = new StringBuilder()
+			.append("<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n")
+			.append("<!DOCTYPE svg PUBLIC \"-//W3C//DTD SVG 1.1//EN\" \"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd\">\n")
+			.append(String.format("<svg xmlns=\"http://www.w3.org/2000/svg\" version=\"1.1\" viewBox=\"0 0 %1$d %1$d\" stroke=\"none\">\n",
+				qr.size + brd * 2))
+			.append("\t<rect width=\"100%\" height=\"100%\" fill=\"#FFFFFF\"/>\n")
+			.append("\t<path d=\"");
+		for (int y = 0; y < qr.size; y++) {
+			for (int x = 0; x < qr.size; x++) {
+				if (qr.getModule(x, y)) {
+					if (x != 0 || y != 0)
+						sb.append(" ");
+					sb.append(String.format("M%d,%dh1v1h-1z", x + brd, y + brd));
+				}
+			}
+		}
+		return sb
+			.append("\" fill=\"#000000\"/>\n")
+			.append("</svg>\n")
+			.toString();
+	}
+	
 }

java/src/main/java/io/nayuki/qrcodegen/package-info.java

@@ -10,7 +10,7 @@
  *   <li><p>Available in 6 programming languages, all with nearly equal functionality: Java, TypeScript/JavaScript, Python, Rust, C++, C</p></li>
  *   <li><p>Significantly shorter code but more documentation comments compared to competing libraries</p></li>
  *   <li><p>Supports encoding all 40 versions (sizes) and all 4 error correction levels, as per the QR Code Model 2 standard</p></li>
- *   <li><p>Output formats: Raw modules/pixels of the QR symbol, SVG XML string</p></li>
+ *   <li><p>Output format: Raw modules/pixels of the QR symbol</p></li>
  *   <li><p>Encodes numeric and special-alphanumeric text in less space than general text</p></li>
  *   <li><p>Open source code under the permissive MIT License</p></li>
  * </ul>