生成二维码的两种方式
今天项目上做了一个二维码的功能，在此记录一下。
功能描述
点击一个超链接，弹出展示二维码的弹出框。
准备
首先下载好生成二维码需要使用到的jar包，下载地址：http://central.maven.org/maven2/com/google/zxing/core/3.3.2/core-3.3.2.jar
将下载好的jar包导入项目，将以下工具类放到项目中：
package com.util; 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); } }
package com.util; import java.awt.BasicStroke; 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.io.OutputStream; import java.util.Hashtable; import java.util.Random; import javax.imageio.ImageIO; import javax.servlet.http.HttpServletResponse; import com.google.zxing.BarcodeFormat; import com.google.zxing.BinaryBitmap; import com.google.zxing.DecodeHintType; import com.google.zxing.EncodeHintType; import com.google.zxing.MultiFormatReader; import com.google.zxing.MultiFormatWriter; import com.google.zxing.Result; import com.google.zxing.WriterException; import com.google.zxing.common.BitMatrix; import com.google.zxing.common.HybridBinarizer; import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel; public class QRCodeUtil { private static final String CHARSET = "utf-8"; private static final String FORMAT_NAME = "JPG"; // 二维码尺寸 private static final int QRCODE_SIZE = 300; // LOGO宽度 private static final int WIDTH = 60; // LOGO高度 private static final int HEIGHT = 60; private static BufferedImage createImage(String content, String imgPath, boolean needCompress) throws Exception { Hashtable hints = new Hashtable(); hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H); hints.put(EncodeHintType.CHARACTER_SET, CHARSET); hints.put(EncodeHintType.MARGIN, 1); BitMatrix bitMatrix = new MultiFormatWriter().encode(content, BarcodeFormat.QR_CODE, QRCODE_SIZE, QRCODE_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++) { image.setRGB(x, y, bitMatrix.get(x, y) ? 0xFF000000 : 0xFFFFFFFF); } } if (imgPath == null || "".equals(imgPath)) { return image; } // 插入图片 QRCodeUtil.insertImage(image, imgPath, needCompress); return image; } private static void insertImage(BufferedImage source, String imgPath, boolean needCompress) throws Exception { File file = new File(imgPath); if (!file.exists()) { System.err.println("" + imgPath + " 该文件不存在！"); return; } Image src = ImageIO.read(new File(imgPath)); int width = src.getWidth(null); int height = src.getHeight(null); if (needCompress) { // 压缩LOGO if (width > WIDTH) { width = WIDTH; } if (height > HEIGHT) { height = HEIGHT; } 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; } // 插入LOGO Graphics2D graph = source.createGraphics(); int x = (QRCODE_SIZE - width) / 2; int y = (QRCODE_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(); } public static void encode(String content, String imgPath, String destPath, boolean needCompress) throws Exception { BufferedImage image = QRCodeUtil.createImage(content, imgPath, needCompress); mkdirs(destPath); // String file = new Random().nextInt(99999999)+".jpg"; // ImageIO.write(image, FORMAT_NAME, new File(destPath+"/"+file)); ImageIO.write(image, FORMAT_NAME, new File(destPath)); } public static BufferedImage encode(String content, String imgPath, boolean needCompress) throws Exception { BufferedImage image = QRCodeUtil.createImage(content, imgPath, needCompress); return image; } 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(); } } public static void encode(String content, String imgPath, String destPath) throws Exception { QRCodeUtil.encode(content, imgPath, destPath, false); } // 被注释的方法 /* * public static void encode(String content, String destPath, boolean * needCompress) throws Exception { QRCodeUtil.encode(content, null, destPath, * needCompress); } */ public static void encode(String content, String destPath) throws Exception { QRCodeUtil.encode(content, null, destPath, false); } public static void encode(String content, String imgPath, OutputStream output, boolean needCompress) throws Exception { BufferedImage image = QRCodeUtil.createImage(content, imgPath, needCompress); ImageIO.write(image, FORMAT_NAME, output); } public static void encode(String content, OutputStream output) throws Exception { QRCodeUtil.encode(content, null, output, false); } public static String decode(File file) 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, CHARSET); result = new MultiFormatReader().decode(bitmap, hints); String resultStr = result.getText(); return resultStr; } public static String decode(String path) throws Exception { return QRCodeUtil.decode(new File(path)); } public static void creatRrCode(String contents, int width, int height,HttpServletResponse response) { Hashtable hints = new Hashtable(); hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H); //容错级别最高 hints.put(EncodeHintType.CHARACTER_SET, "utf-8"); //设置字符编码 hints.put(EncodeHintType.MARGIN, 1); //二维码空白区域,最小为0也有白边,只是很小,最小是6像素左右 try { BitMatrix bitMatrix = new MultiFormatWriter().encode(contents, BarcodeFormat.QR_CODE, width, height, hints); // 1、读取文件转换为字节数组 // ByteArrayOutputStream out = new ByteArrayOutputStream(); BufferedImage image = toBufferedImage(bitMatrix); //转换成png格式的IO流 ImageIO.write(image, "png", response.getOutputStream()); // byte[] bytes = out.toByteArray(); // // 2、将字节数组转为二进制 // BASE64Encoder encoder = new BASE64Encoder(); // binary = encoder.encodeBuffer(bytes).trim(); } catch (WriterException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } } /** * image流数据处理 * * @author ianly */ public static BufferedImage toBufferedImage(BitMatrix matrix) { int width = matrix.getWidth(); int height = matrix.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, matrix.get(x, y) ? 0xFF000000 : 0xFFFFFFFF); } } return image; } }
1.后台生成二维码图片并保存图片
超链接以及js代码如下：
[<a href="#" onclick="showCode('<%=barcode%>')" class="unline">二维码</a>]
//生成二维码方法
function showCode(barcode){
top.layer.open({
type: 2,
title:'',
cancel: function(){
},
area: ['300px', '300px'],
fixed: false, //不固定
maxmin: false,
Boolean: false,
content: '<%=request.getContextPath()%>/frame/showCode.do?barcode='+barcode
});
}
后台生成二维码的代码：
/** * 生成二维码 */ public String showCode() { try { String barcode = request.getParameter("barcode"); request.setAttribute("barcode", barcode); log.info("barcode-------------"+barcode); // 存放在二维码中的内容 String text = "http://127.0.0.1:8080/扫描后需要调用的地址?barcode="+barcode; // 嵌入二维码的图片路径 String imgPath = "D:/md5file/20191119181532.jpg"; // 生成的二维码的路径及名称 String destPath = "D:/md5file/"+barcode+".jpg"; //生成二维码 QRCodeUtil.encode(text, imgPath, destPath, true); // 解析二维码 String str = QRCodeUtil.decode(destPath); // 打印出解析出的内容 System.out.println(str); } catch (Exception e) { e.printStackTrace(); } return "showCode"; }
展示二维码的容器：
<!-- 存放二维码的容器 --> <img src="二维码图片保存的地址"/>
2.页面实时生成二维码展示
超链接以及点击事件方法：
[<a href="#" onclick="showCode('<%=mywork.getFormcode()%>')" class="unline">二维码</a>]
//展示二维码
function showCode(barcode){
top.layer.open({
type: 2,
title:'',
cancel: function(){
},
area: ['300px', '300px'],
fixed: false, //不固定
maxmin: false,
Boolean: false,
content: '<%=request.getContextPath()%>/jsp/frame/mywork/showCode.jsp?barcode='+barcode
});
}
此处是点击超链接直接跳到弹框页面，在弹框页面上调后台生成二维码：
public void qrcode() { String barcode = request.getParameter("barcode"); String content = 扫描二维码需要调用的后台地址?barcode="+barcode; //调用工具类，生成二维码 QRCodeUtil.creatRrCode(content, 300,300,response); //300为图片高度和宽度 }
弹框页面代码：
<% String barcode = request.getParameter("barcode"); request.setAttribute("barcode", barcode); %> <body> <input type="hidden" name="barcode" id="barcode" value="${barcode}"> <!-- 存放二维码的容器 --> <img src="<%=request.getContextPath()%>/frame/qrcode.do?barcode=${barcode}"/> </body>
