使用zxing生成二维码

需要的jar包有：core.jar和zxing-javase.jar

其中：zxing-javase.jar包中的MatrixToImageWriter类在不同版本的jdk环境下编译后打成的jar包在不匹配的jdk中可能会报错，所以直接用其源代码：

MatrixToImageWriter.java

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);
	    }
	}
}

QRCodeUtil.java

import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
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.LuminanceSource;
import com.google.zxing.MultiFormatReader;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.ReaderException;
import com.google.zxing.Result;
import com.google.zxing.client.j2se.BufferedImageLuminanceSource;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.common.HybridBinarizer;
  
public class QRCodeUtil {  
    public static void main(String[] args) {  
        QRCodeUtil codeUtil=new QRCodeUtil();  
        String str = "http://blog.youkuaiyun.com/lzghxjt";
        String path = "F:/QRCode.jpg";
        codeUtil.encode(str, path);  
        codeUtil.decode(path);  
    }  
  
    /*
     * 编码：
     * 第1步：将内容转换成二维矩阵
     * 第2步：将二维矩阵转换成图片
     * */
    public void encode(String str, String path) {  
        try {  
            BitMatrix byteMatrix; 
            //将文字转换成二维矩阵，并设置矩阵大小，这里的矩阵大小就是后面生成的图片像素大小 
            byteMatrix = new MultiFormatWriter().encode(new String(str.getBytes("UTF-8"),"UTF-8"), BarcodeFormat.QR_CODE, 800, 800); 
            File file = new File(path);
            //将矩阵文件转换成图片文件  
            MatrixToImageWriter.writeToFile(byteMatrix, "jpg", file);
        } catch (Exception e) {  
            e.printStackTrace();  
        }  
    }  
  
    /*
     * 解码：
     * 第1步：将图片反解码为二维矩阵
     * 第2步：将该二维矩阵解码为内容
     * */ 
    public void decode(String imgPath) {  
        try {  
            File file = new File(imgPath);//获取该图片文件  
            BufferedImage image;  
            try {  
                image = ImageIO.read(file);  
                if (image == null) {  
                    System.out.println("不能解析该二维码");  
                }  
                LuminanceSource source = new BufferedImageLuminanceSource(image);  
                BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));  
                Result result;  
                Hashtable<DecodeHintType, String> hints = new Hashtable<DecodeHintType, String>();//将图片反解码为二维矩阵  
                hints.put(DecodeHintType.CHARACTER_SET, "UTF-8");  
                result = new MultiFormatReader().decode(bitmap, hints);//将该二维矩阵解码成内容  
                String resultStr = result.getText();  
                System.out.println("解码结果："+resultStr);  
            } catch (IOException ioe) {  
                System.out.println(ioe.toString());  
            } catch (ReaderException re) {  
                System.out.println(re.toString());  
            }  
        } catch (Exception ex) {  
        	System.out.println(ex.toString());
        }  
    }  
}

本示例中编码生成的二维码是：

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