Java实现二维码技术探讨。

Java生成二维码方法有三种：

1： 使用SwetakeQRCode在Java项目中生成二维码 

http://swetake.com/qr/ 下载地址 

或着http://sourceforge.jp/projects/qrcode/downloads/28391/qrcode.zip 

这个是日本人写的，生成的是我们常见的方形的二维码 

能够用中文 如：5677777ghjjjjj 



2： 使用BarCode4j生成条形码和二维码 

BarCode4j网址：http://sourceforge.net/projects/barcode4j/ 



barcode4j是使用datamatrix的二维码生成算法，为支持qr的算法 

datamatrix是欧美的标准。qr为日本的标准， 

barcode4j一般生成出来是长方形的



如：88777alec000yan 

这个博客这方面说的挺清楚的： 

http://baijinshan.iteye.com/blog/1004554

3、如今具体介绍第三种也是经常使用的方式：利用Zxing生成二维码

Zxing是Google提供的关于条码（一维码、二维码）的解析工具，提供了二维码的生成与解析的方法，如今我简介一下使用Java利用Zxing生成与解析二维码。

第一步:将Zxing-core.jar 包增加项目中。

第二步 加入下面三个Java文件，三个文件功能例如以下：

MatrixToImageWriter.java  生成二维码图片。

BufferedImageLuminanceSource.java   解析二维码图片。

BarcodeFactory.java  生成带头像的二维码。

MatrixToImageWriter.java

import com.google.zxing.BarcodeFormat;

import com.google.zxing.EncodeHintType;

import com.google.zxing.MultiFormatWriter;

import com.google.zxing.common.BitMatrix;

import javax.imageio.ImageIO;

import java.io.File;

import java.io.OutputStream;

import java.io.IOException;

import java.util.Hashtable;

import java.awt.image.BufferedImage;

public final class MatrixToImageWriter {

	private static final int BLACK = 0xFF000000;

	private static final int WHITE = 0xFFFFFFFF;

	private MatrixToImageWriter() {

	}

	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) ?

BLACK : WHITE);

			}

		}

		return image;

	}

	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);

		}

	}

	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);

		}

	}

	public static void main(String[] args) throws Exception {

		String text = "二维码内容，能够是链接也能够是文本";

		int width = 300;

		int height = 300;

		Hashtable hints = new Hashtable();

		hints.put(EncodeHintType.CHARACTER_SET, "utf-8");//内容所使用编码

		BitMatrix bitMatrix = new MultiFormatWriter().encode(text, BarcodeFormat.QR_CODE, width, height, hints);

		File outputFile = new File("E:/qrtest/生成普通二维码.jpg");

		//File.separator

		String format = "jpg";//二维码的图片格式

		MatrixToImageWriter.writeToFile(bitMatrix, format, outputFile);

	}

}

BufferedImageLuminanceSource.java

import com.google.zxing.Binarizer;

import com.google.zxing.BinaryBitmap;

import com.google.zxing.EncodeHintType;

import com.google.zxing.LuminanceSource;

import com.google.zxing.MultiFormatReader;

import com.google.zxing.Result;

import com.google.zxing.common.HybridBinarizer;

import java.awt.Graphics2D;

import java.awt.geom.AffineTransform;

import java.awt.image.BufferedImage;

import java.io.File;

import java.util.HashMap;

import java.util.Map;

import javax.imageio.ImageIO;

public final 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);

	}

	public static void main(String[] args) {

		//解析二维码

		try {

			MultiFormatReader formatReader = new MultiFormatReader();

			String filePath = "E:/qrtest/生成普通二维码.jpg";

			File file = new File(filePath);

			BufferedImage image = ImageIO.read(file);

			LuminanceSource source = new BufferedImageLuminanceSource(image);

			Binarizer binarizer = new HybridBinarizer(source);

			BinaryBitmap binaryBitmap = new BinaryBitmap(binarizer);

			Map hints = new HashMap();

			hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");

			Result result = formatReader.decode(binaryBitmap, hints);

			System.out.println("result = " + result.toString());

			System.out.println("resultFormat = " + result.getBarcodeFormat());

			System.out.println("resultText = " + result.getText());

		} catch (Exception e) {

			e.printStackTrace();

		}

	}

}

BarcodeFactory.java

import java.awt.Color;

import java.awt.Graphics2D;

import java.awt.Image;

import java.awt.geom.AffineTransform;

import java.awt.image.AffineTransformOp;

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.WriterException;

import com.google.zxing.common.BitMatrix;

import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;

public class BarcodeFactory {

	// 图片宽度的一般

	private static final int IMAGE_WIDTH = 80;

	private static final int IMAGE_HEIGHT = 80;

	private static final int IMAGE_HALF_WIDTH = IMAGE_WIDTH / 2;

	private static final int FRAME_WIDTH = 2;

	// 二维码写码器

	private static MultiFormatWriter mutiWriter = new MultiFormatWriter();

	/**

	 * 将srcImagePath嵌入到destImagePath

	 */

	public static void encode(String content, int width, int height, String srcImagePath, String destImagePath) {

		try {

			ImageIO.write(genBarcode(content, width, height, srcImagePath), "jpg", new File(destImagePath));

		} catch (IOException e) {

			e.printStackTrace();

		} catch (WriterException e) {

			e.printStackTrace();

		}

	}

	private static BufferedImage genBarcode(String content, int width, int height, String srcImagePath)

			throws WriterException, IOException {

		// 读取源图像

		BufferedImage scaleImage = scale(srcImagePath, IMAGE_WIDTH, IMAGE_HEIGHT, true);

		int[][] srcPixels = new int[IMAGE_WIDTH][IMAGE_HEIGHT];

		for (int i = 0; i < scaleImage.getWidth(); i++) {

			for (int j = 0; j < scaleImage.getHeight(); j++) {

				srcPixels[i][j] = scaleImage.getRGB(i, j);

			}

		}

		Map<EncodeHintType, Object> hint = new HashMap<EncodeHintType, Object>();

		hint.put(EncodeHintType.CHARACTER_SET, "utf-8");

		hint.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);

		// 生成二维码

		BitMatrix matrix = mutiWriter.encode(content, BarcodeFormat.QR_CODE, width, height, hint);

		// 二维矩阵转为一维像素数组

		int halfW = matrix.getWidth() / 2;

		int halfH = matrix.getHeight() / 2;

		int[] pixels = new int[width * height];

		for (int y = 0; y < matrix.getHeight(); y++) {

			for (int x = 0; x < matrix.getWidth(); x++) {

				// 读取图片

				if (x > halfW - IMAGE_HALF_WIDTH && x < halfW + IMAGE_HALF_WIDTH && y > halfH - IMAGE_HALF_WIDTH

						&& y < halfH + IMAGE_HALF_WIDTH) {

					pixels[y * width + x] = srcPixels[x - halfW + IMAGE_HALF_WIDTH][y - halfH + IMAGE_HALF_WIDTH];

				}

				// 在图片四周形成边框

				else if ((x > halfW - IMAGE_HALF_WIDTH - FRAME_WIDTH && x < halfW - IMAGE_HALF_WIDTH + FRAME_WIDTH

						&& y > halfH - IMAGE_HALF_WIDTH - FRAME_WIDTH && y < halfH + IMAGE_HALF_WIDTH + FRAME_WIDTH)

						|| (x > halfW + IMAGE_HALF_WIDTH - FRAME_WIDTH && x < halfW + IMAGE_HALF_WIDTH + FRAME_WIDTH

								&& y > halfH - IMAGE_HALF_WIDTH - FRAME_WIDTH && y < halfH + IMAGE_HALF_WIDTH + FRAME_WIDTH)

						|| (x > halfW - IMAGE_HALF_WIDTH - FRAME_WIDTH && x < halfW + IMAGE_HALF_WIDTH + FRAME_WIDTH

								&& y > halfH - IMAGE_HALF_WIDTH - FRAME_WIDTH && y < halfH - IMAGE_HALF_WIDTH + FRAME_WIDTH)

						|| (x > halfW - IMAGE_HALF_WIDTH - FRAME_WIDTH && x < halfW + IMAGE_HALF_WIDTH + FRAME_WIDTH

								&& y > halfH + IMAGE_HALF_WIDTH - FRAME_WIDTH && y < halfH + IMAGE_HALF_WIDTH + FRAME_WIDTH)) {

					pixels[y * width + x] = 0xfffffff;

				} else {

					// 此处能够改动二维码的颜色，能够分别制定二维码和背景的颜色；

					pixels[y * width + x] = matrix.get(x, y) ? 0xff000000 : 0xfffffff;

				}

			}

		}

		BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);

		image.getRaster().setDataElements(0, 0, width, height, pixels);

		return image;

	}

	/**

	 * 把传入的原始图像按高度和宽度进行缩放。生成符合要求的图标

	 *

	 * @param srcImageFile

	 *            源文件地址

	 * @param height

	 *            目标高度

	 * @param width

	 *            目标宽度

	 * @param hasFiller

	 *            比例不正确时是否须要补白：true为补白; false为不补白;

	 * @throws IOException

	 */

	private static BufferedImage scale(String srcImageFile, int height, int width, boolean hasFiller) throws IOException {

		double ratio = 0.0; // 缩放比例

		File file = new File(srcImageFile);

		BufferedImage srcImage = ImageIO.read(file);

		Image destImage = srcImage.getScaledInstance(width, height, BufferedImage.SCALE_SMOOTH);

		// 计算比例

		if ((srcImage.getHeight() > height) || (srcImage.getWidth() > width)) {

			if (srcImage.getHeight() > srcImage.getWidth()) {

				ratio = (new Integer(height)).doubleValue() / srcImage.getHeight();

			} else {

				ratio = (new Integer(width)).doubleValue() / srcImage.getWidth();

			}

			AffineTransformOp op = new AffineTransformOp(AffineTransform.getScaleInstance(ratio, ratio), null);

			destImage = op.filter(srcImage, null);

		}

		if (hasFiller) {// 补白

			BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);

			Graphics2D graphic = image.createGraphics();

			graphic.setColor(Color.white);

			graphic.fillRect(0, 0, width, height);

			if (width == destImage.getWidth(null))

				graphic.drawImage(destImage, 0, (height - destImage.getHeight(null)) / 2, destImage.getWidth(null), destImage

						.getHeight(null), Color.white, null);

			else

				graphic.drawImage(destImage, (width - destImage.getWidth(null)) / 2, 0, destImage.getWidth(null), destImage

						.getHeight(null), Color.white, null);

			graphic.dispose();

			destImage = image;

		}

		return (BufferedImage) destImage;

	}

	public static void main(String[] args) {

		//src.jpg为头像文件

		BarcodeFactory.encode("http://www.baidu.com", 300, 300, "E:/qrtest/src.jpg","E:/qrtest/生成带头像的二维码.jpg");

	}

}