Java后台直接生成二维码

1、其实jquery也可以直接生成二维码的，但我测试的时候，二维码生成后太模糊，难以识别。所以在这里介绍在后来生成二维码的方式。

2、不善于文字描述，直接上代码了。

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: 二维码生成工具类</p>* @author Administrator* @version * @since */
public final class QRCodeUtil extends LuminanceSource {private static final Logger logger = LoggerFactory.getLogger(QRCodeUtil.class);// 二维码颜色private static final int BLACK = 0xFF000000;// 二维码颜色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;}@Overridepublic 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;}@Overridepublic 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;}@Overridepublic boolean isCropSupported() {return true;}@Overridepublic LuminanceSource crop(int left, int top, int width, int height) {return new QRCodeUtil(image, this.left + left, this.top + top, width, height);}@Overridepublic boolean isRotateSupported() {return true;}@Overridepublic 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;}/*** 生成二维码图片* * @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);}}/*** 生成二维码图片流* * @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);}}/*** 根据内容，生成指定宽高、指定格式的二维码图片** @param text   内容* @param width  宽* @param height 高* @param format 图片格式* @return 生成的二维码图片路径* @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");// 指定编码格式hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.L);// 指定纠错等级hints.put(EncodeHintType.MARGIN, 1); // 白边大小，取值范围0~4BitMatrix bitMatrix = new MultiFormatWriter().encode(text, BarcodeFormat.QR_CODE, width, height, hints);File outputFile = new File(pathName);writeToFile(bitMatrix, format, outputFile);return pathName;}/*** 输出二维码图片流* * @param text 二维码内容* @param width 二维码宽* @param height 二维码高* @param format 图片格式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");// 指定编码格式hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.L);// 指定纠错等级hints.put(EncodeHintType.MARGIN, 1); // 白边大小，取值范围0~4BitMatrix bitMatrix = new MultiFormatWriter().encode(text, BarcodeFormat.QR_CODE, width, height, hints);writeToStream(bitMatrix, format, response.getOutputStream());}/*** 解析指定路径下的二维码图片** @param filePath 二维码图片路径* @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 为：" + result.toString());logger.info("resultFormat 为：" + result.getBarcodeFormat());logger.info("resultText 为：" + result.getText());// 设置返回值content = result.getText();} catch (Exception e) {logger.error(e.getMessage());}return content;}public static void main(String[] args) {String text = "hello world!"; // 随机生成验证码System.out.println("随机码： " + text);int width = 100; // 二维码图片的宽int height = 100; // 二维码图片的高String format = "png"; // 二维码图片的格式try {// 生成二维码图片，并返回图片路径String pathName = generateQRCode(text, width, height, format, "D:/new.png");System.out.println("生成二维码的图片路径： " + pathName);String content = parseQRCode(pathName);System.out.println("解析出二维码的图片的内容为： " + content);} catch (Exception e) {e.printStackTrace();}}}