当根据需要,我们需要在页面上生成动态可变的二维码的时候,可以根据本例做为参考,本例使用Servlet做范例,使用的是Google的zxing二维码工具。
更新代码:2016-10-19
1.重构了重载
2.现在二维码是彩色的!
首先,我们需要写两个工具类,外加一个Servlet,总共三个类。
第一个:BufferedImageLuminanceSource.java
package com.againfly.qrcode; import java.awt.Graphics2D; import java.awt.geom.AffineTransform; import java.awt.image.BufferedImage; import com.google.zxing.LuminanceSource; 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; } 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; } 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; } public boolean isCropSupported() { return true; } public LuminanceSource crop(int left, int top, int width, int height) { return new BufferedImageLuminanceSource(image, this.left + left, this.top + top, width, height); } public boolean isRotateSupported() { return true; } 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); } }
第二个:QRCodeUtil.java
package com.againfly.qrcode; import java.awt.BasicStroke; import java.awt.Color; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.Image; import java.awt.Shape; import java.awt.geom.RoundRectangle2D; 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.common.BitMatrix; import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel; public class QRCodeUtil { public static void main(String[] args) throws IOException { String charset = "utf-8"; String text = "http://www.againfly.com/"; String insertImg = "D://q.png"; BufferedImage qr = null; try { QRCodeUtil.CHARSET = charset; qr = QRCodeUtil.createImage(text, 300, insertImg, 62); } catch (Exception e) { e.printStackTrace(); } ImageIO.write(qr, "png", new File("D://q.jpg")); } private static String CHARSET = "utf-8"; // 二维码尺寸 private static final int QRCODE_SIZE = 300; public static BufferedImage createImage(String content) throws Exception{ return createImage(content, ""); } public static BufferedImage createImage(String content, String logoPath) throws Exception{ File logoFile = new File(logoPath); return createImage(content, QRCODE_SIZE, logoFile); } public static BufferedImage createImage(String content, File logoFile) throws Exception{ return createImage(content, QRCODE_SIZE, logoFile); } public static BufferedImage createImage(String content, int size, File logoFile) throws Exception{ return createImage(content, size, logoFile, (int)(size / 5)); } public static BufferedImage createImage(String content, int size, String logoPath, int logoSize) throws Exception { return createImage(content, size, new File(logoPath), logoSize); } public static BufferedImage createImage(String content, int size, File logoFile, int logoSize) throws Exception { Map<EncodeHintType, Object> hints = new HashMap<EncodeHintType, Object>(); hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.Q); hints.put(EncodeHintType.CHARACTER_SET, CHARSET); hints.put(EncodeHintType.MARGIN, 1); BitMatrix bitMatrix = new MultiFormatWriter().encode(content, BarcodeFormat.QR_CODE, size, size, hints); 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++) { //自定义二维码颜色和背景颜色 int num1 = (int) (50 - (50.0 - 13.0) / bitMatrix.getHeight() * (y + 1)); int num2 = (int) (165 - (165.0 - 72.0) / bitMatrix.getHeight() * (y + 1)); int num3 = (int) (162 - (162.0 - 107.0) / bitMatrix.getHeight() * (y + 1)); Color color = new Color(num1, num2, num3); int colorInt = color.getRGB(); //image.setRGB(x, y, bitMatrix.get(x, y) ? 0xFF000000 : 0xFFFFFFFF); image.setRGB(x, y, bitMatrix.get(x, y) ? colorInt : 0xFFFFFFFF); } } // 插入logo图片 if (null != logoFile) { QRCodeUtil.insertImage(image, size, logoFile, logoSize); } return image; } private static void insertImage(BufferedImage source, int size, File logoFile, int logoSize) throws Exception { if (!logoFile.exists()) { System.err.println("" + logoFile +" 该文件不存在!"); return; } Image src = ImageIO.read(logoFile); int width = src.getWidth(null); int height = src.getHeight(null); { // 压缩LOGO if (width > logoSize) { width = logoSize; } if (height > logoSize) { height = logoSize; } Image image = src.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(); src = image; } Graphics2D graph = source.createGraphics();// 插入LOGO int x = (size - width) / 2; int y = (size - height) / 2; graph.drawImage(src, x, y, width, height, null); Shape shape = new RoundRectangle2D.Float(x, y, width, width, 6, 6); graph.setStroke(new BasicStroke(3f)); graph.draw(shape); graph.dispose(); } }
第三个Servlet:QRDemo.java
package com.againfly.demo; import java.awt.image.BufferedImage; import java.io.IOException; import javax.imageio.ImageIO; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import com.againfly.qrcode.QRCodeUtil; public class QRDemo extends HttpServlet { @Override protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("image/png"); response.setHeader("Pragma", "no-cache");//禁止图像缓存。 response.setHeader("Cache-Control", "no-cache"); response.setDateHeader("Expires", 0); String formatName = "PNG"; String charset = "utf-8"; String text = "http://www.againfly.com"; String insertImg = "/MYOTee.JPG"; BufferedImage qr = null; try { qr = QRCodeUtil.createImage(text, insertImg); } catch (Exception e) { e.printStackTrace(); } ImageIO.write(qr, formatName, response.getOutputStream()); } }
////////////////////////////////////////////_/
这是彩色的图:
效果图:
2016-10-19
补充内容:从webroot下获取File文件
public static File getRootFile(String src) { ClassLoader classLoader = Thread.currentThread().getContextClassLoader(); if (classLoader == null) { classLoader = ClassLoader.getSystemClassLoader(); } java.net.URL url = classLoader.getResource(""); String ROOT_CLASS_PATH = url.getPath() + "/"; File rootFile = new File(ROOT_CLASS_PATH); String WEB_INFO_DIRECTORY_PATH = rootFile.getParent() + "/"; File webInfoDir = new File(WEB_INFO_DIRECTORY_PATH); String SERVLET_CONTEXT_PATH = webInfoDir.getParent() + "/"; // 这里 SERVLET_CONTEXT_PATH 就是WebRoot的路径 String path = SERVLET_CONTEXT_PATH + "/" + src; path = path.replaceAll("%20", " "); return new File(path); }
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