Java利用Zxing生成二维码

需要导入core-3.1.0.jar

可以通过http://download.youkuaiyun.com/detail/semial/9439331链接下载（实例+jar包）

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，现在我简单介绍一下使用Java利用Zxing生成与解析二维码

1、二维码的生成

 　　1.1 将Zxing-core.jar 包加入到classpath下。

　　 1.2 二维码的生成需要借助MatrixToImageWriter类，该类是由Google提供的，可以将该类拷贝到源码中，这里我将该类的源码贴上，可以直接使用。

package com.han.demo;

import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.io.OutputStream;

import javax.imageio.ImageIO;

import com.google.zxing.common.BitMatrix;

public 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);
	     }
	   }
	 

}

2、二维码的解析

　　2.1 将Zxing-core.jar 包加入到classpath下。　　

　　2.2 和生成一样，我们需要一个辅助类（ BufferedImageLuminanceSource），同样该类Google也提供了，这里我同样将该类的源码贴出来，可以直接拷贝使用个，省去查找的麻烦

package com.han.demo;

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;
	}

	@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);
	}

}

3、测试生成二维码

package com.han.demo;

import java.io.File;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

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;

public class MyTest {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		 try {
			String content = "https://www.baidu.com";
			 String path = "E:/";
			 
			 MultiFormatWriter multiFormatWriter = new MultiFormatWriter();
			 Map hints = new HashMap();
			 hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
			 BitMatrix bitMatrix = multiFormatWriter.encode(content, BarcodeFormat.QR_CODE, 400, 400,hints);
			 File file1 = new File(path,"01.jpg");
			 MatrixToImageWriter.writeToFile(bitMatrix, "jpg", file1);
		} catch (WriterException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}  

}