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          Java如何實(shí)現(xiàn)二維碼?【附源碼】

          共 10559字,需瀏覽 22分鐘

           ·

          2020-08-20 21:59

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          來(lái)源:http://suo.im/5R6ewH



          步驟1

          第一步首先創(chuàng)建一個(gè)普通的 Maven 項(xiàng)目,然后要實(shí)現(xiàn)二維碼功能,我們肯定要使用別人提供好的 Jar 包,這里我用的是 google 提供的 jar,pom.xml 文件配置如下:

          <project xmlns="http://maven.apache.org/POM/4.0.0"         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">    <modelVersion>4.0.0modelVersion>
          <groupId>org.javaboygroupId> <artifactId>QRCodeartifactId> <version>1.0-SNAPSHOTversion>

          <dependencies> <dependency> <groupId>com.google.zxinggroupId> <artifactId>coreartifactId> <version>3.3.0version> dependency> dependencies>
          project>


          步驟2

          然后使用 google 提供的工具類,在項(xiàng)目根目錄下創(chuàng)建一個(gè) util 包,將所需要的工具類放進(jìn)去。

          工具類1 (BufferedImageLuminanceSource)

          不廢話,直接上代碼

          package org.javaboy.util;
          import java.awt.Graphics2D;import java.awt.geom.AffineTransform;import java.awt.image.BufferedImage;
          import com.google.zxing.LuminanceSource;
          /** * @author bai
          * @date 2020/7/1 9:27
          */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; }
          @Override 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; }
          @Override 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; }
          @Override public boolean isCropSupported() { return true; }
          @Override public LuminanceSource crop(int left, int top, int width, int height) { return new BufferedImageLuminanceSource(image, this.left + left, this.top + top, width, height); }
          @Override public boolean isRotateSupported() { return true; }
          @Override 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); }
          }


          工具類2 (QRCodeUtil)

          這里面可以修改一些參數(shù),例如二維碼的尺寸,寬高等等。

          package org.javaboy.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.OutputStream;import java.util.Hashtable;import javax.imageio.ImageIO;
          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.common.BitMatrix;import com.google.zxing.common.HybridBinarizer;import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
          /** * @author bai
          * @date 2020/7/1 9:29
          */public class QRCodeUtil { private static final String CHARSET = "utf-8"; private static final String FORMAT_NAME = "JPG"; // 二維碼尺寸 private static final int QRCODE_SIZE = 300; // LOGO寬度 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; } // 插入圖片 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 + " 該文件不存在!"); return; } Image src = ImageIO.read(new File(imgPath)); int width = src.getWidth(null); int height = src.getHeight(null); if (needCompress) { // 壓縮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); // 繪制縮小后的圖 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); // 當(dāng)文件夾不存在時(shí),mkdirs會(huì)自動(dòng)創(chuàng)建多層目錄,區(qū)別于mkdir.(mkdir如果父目錄不存在則會(huì)拋出異常) 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); } // 被注釋的方法 /* * 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)); }
          }


          啟動(dòng)類

          這一步就是調(diào)用方法,一般大家使用這種功能都是為了實(shí)現(xiàn)業(yè)務(wù),例如常見(jiàn)的掃描二維碼跳轉(zhuǎn)鏈接(頁(yè)面),掃描二維碼出現(xiàn)文字等等。有些二維碼中間還帶有 Logo 這種圖片,將需要嵌入二維碼的圖片路徑準(zhǔn)備好就沒(méi)有問(wèn)題。

          package org.javaboy;
          import org.javaboy.util.QRCodeUtil;
          /** * @author bai
          * @date 2020/7/1 9:31
          */public class QRCodeApplication { public static void main(String[] args) throws Exception { // 存放在二維碼中的內(nèi)容 // 二維碼中的內(nèi)容可以是文字,可以是鏈接等 String text = "http://www.baidu.com"; // 嵌入二維碼的圖片路徑 //String imgPath = "C:\\Users\\Administrator\\Pictures\\img\\dog.jpg"; // 生成的二維碼的路徑及名稱 String destPath = "C:\\Users\\bai\\Pictures\\img\\code" + System.currentTimeMillis() + ".jpg"; //生成二維碼 QRCodeUtil.encode(text, null, destPath, true); // 解析二維碼 String str = QRCodeUtil.decode(destPath); // 打印出解析出的內(nèi)容 System.out.println(str); }}


          效果截圖

          源碼奉上

          碼云:https://gitee.com/jian_bo_bai/QRCode


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