Java後臺直接生成二維碼html
一、其實jquery也能夠直接生成二維碼的,但我測試的時候,二維碼生成後太模糊,難以識別。因此在這裏介紹在後來生成二維碼的方式。java
二、不善於文字描述,直接上代碼了。jquery
import java.awt.Graphics2D; import java.awt.geom.AffineTransform; import java.awt.image.BufferedImage; import java.io.File; import java.io.IOException; import java.io.OutputStream; import java.util.HashMap; import java.util.Hashtable; import java.util.Map; import javax.imageio.ImageIO; import javax.servlet.http.HttpServletResponse; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.google.zxing.BarcodeFormat; import com.google.zxing.Binarizer; import com.google.zxing.BinaryBitmap; import com.google.zxing.DecodeHintType; import com.google.zxing.EncodeHintType; import com.google.zxing.LuminanceSource; 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; /** * <p>Title:QRCodeUtil </p> * <p>Description: 二維碼生成工具類</p> * @author Administrator * @version * @since */ public final class QRCodeUtil extends LuminanceSource { private static final Logger logger = LoggerFactory.getLogger(QRCodeUtil.class); // 二維碼顏色 private static final int BLACK = 0xFF000000; // 二維碼顏色 private static final int WHITE = 0xFFFFFFFF; private final BufferedImage image; private final int left; private final int top; public QRCodeUtil(BufferedImage image) { this(image, 0, 0, image.getWidth(), image.getHeight()); } public QRCodeUtil(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 QRCodeUtil(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 QRCodeUtil(rotatedImage, top, sourceWidth - (left + width), getHeight(), width); } /** * @param matrix * @return */ private 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) ? BLACK : WHITE); } } return image; } /** * 生成二維碼圖片 * * @param matrix * @param format * @param file * @throws IOException */ public static void writeToFile(BitMatrix matrix, String format, File file) throws IOException { BufferedImage image = toBufferedImage(matrix); if (!ImageIO.write(image, format, file)) { throw new IOException("Could not write an image of format " + format + " to " + file); } } /** * 生成二維碼圖片流 * * @param matrix * @param format * @param stream * @throws IOException */ public static void writeToStream(BitMatrix matrix, String format, OutputStream stream) throws IOException { BufferedImage image = toBufferedImage(matrix); if (!ImageIO.write(image, format, stream)) { throw new IOException("Could not write an image of format " + format); } } /** * 根據內容,生成指定寬高、指定格式的二維碼圖片 * * @param text 內容 * @param width 寬 * @param height 高 * @param format 圖片格式 * @return 生成的二維碼圖片路徑 * @throws Exception */ private static String generateQRCode(String text, int width, int height, String format, String pathName) throws Exception { Hashtable<EncodeHintType, Object> hints = new Hashtable<EncodeHintType, Object>(); hints.put(EncodeHintType.CHARACTER_SET, "utf-8");// 指定編碼格式 hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.L);// 指定糾錯等級 hints.put(EncodeHintType.MARGIN, 1); // 白邊大小,取值範圍0~4 BitMatrix bitMatrix = new MultiFormatWriter().encode(text, BarcodeFormat.QR_CODE, width, height, hints); File outputFile = new File(pathName); writeToFile(bitMatrix, format, outputFile); return pathName; } /** * 輸出二維碼圖片流 * * @param text 二維碼內容 * @param width 二維碼寬 * @param height 二維碼高 * @param format 圖片格式eg: png, jpg, gif * @param response HttpServletResponse * @throws Exception */ public static void generateQRCode(String text, int width, int height, String format, HttpServletResponse response) throws Exception { Hashtable<EncodeHintType, Object> hints = new Hashtable<EncodeHintType, Object>(); hints.put(EncodeHintType.CHARACTER_SET, "utf-8");// 指定編碼格式 hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.L);// 指定糾錯等級 hints.put(EncodeHintType.MARGIN, 1); // 白邊大小,取值範圍0~4 BitMatrix bitMatrix = new MultiFormatWriter().encode(text, BarcodeFormat.QR_CODE, width, height, hints); writeToStream(bitMatrix, format, response.getOutputStream()); } /** * 解析指定路徑下的二維碼圖片 * * @param filePath 二維碼圖片路徑 * @return */ public static String parseQRCode(String filePath) { String content = ""; try { File file = new File(filePath); BufferedImage image = ImageIO.read(file); LuminanceSource source = new QRCodeUtil(image); Binarizer binarizer = new HybridBinarizer(source); BinaryBitmap binaryBitmap = new BinaryBitmap(binarizer); Map<DecodeHintType, Object> hints = new HashMap<DecodeHintType, Object>(); hints.put(DecodeHintType.CHARACTER_SET, "UTF-8"); MultiFormatReader formatReader = new MultiFormatReader(); Result result = formatReader.decode(binaryBitmap, hints); logger.info("result 爲:" + result.toString()); logger.info("resultFormat 爲:" + result.getBarcodeFormat()); logger.info("resultText 爲:" + result.getText()); // 設置返回值 content = result.getText(); } catch (Exception e) { logger.error(e.getMessage()); } return content; } public static void main(String[] args) { String text = "hello world!"; // 隨機生成驗證碼 System.out.println("隨機碼: " + text); int width = 100; // 二維碼圖片的寬 int height = 100; // 二維碼圖片的高 String format = "png"; // 二維碼圖片的格式 try { // 生成二維碼圖片,並返回圖片路徑 String pathName = generateQRCode(text, width, height, format, "D:/new.png"); System.out.println("生成二維碼的圖片路徑: " + pathName); String content = parseQRCode(pathName); System.out.println("解析出二維碼的圖片的內容爲: " + content); } catch (Exception e) { e.printStackTrace(); } } }
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<dependency>
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<groupId>com.google.zxing
</groupId>
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<artifactId>core
</artifactId>
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<version>3.3.0
</version>
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</dependency>