生成带logo的二维码

    生成QR二维码的jar包常见的有日本的QRCode.jar和google的zxing.jar，两种方式我都试过，觉得还是google的更胜一筹。
    生成二维码个人认为麻烦的地方是中间带logo，因为logo的大小与整体二维码的比例需要在一定范围内，不然不会被识别。二维码允许存在logo是利用了二维码的容错功能。QR二维码容错级别分为四个层次：L,M,Q,H（从低到高排序）。
     代码如下:

package com.util;

import java.awt.BasicStroke;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Shape;
import java.awt.geom.RoundRectangle2D;
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 javax.imageio.ImageIO;
import com.google.zxing.BarcodeFormat;
import com.google.zxing.BinaryBitmap;
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.client.j2se.BufferedImageLuminanceSource;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.common.HybridBinarizer;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;


public class QRCodeHelper {
	
		private static final int BLACK = 0xFF000000; 
		private static final int WHITE = 0xFFFFFFFF;
		
		private static HashMap<Integer,ErrorCorrectionLevel> levelMap=new HashMap<Integer,ErrorCorrectionLevel>(){
			{
				put(1,ErrorCorrectionLevel.L);
				put(2,ErrorCorrectionLevel.M);
				put(3,ErrorCorrectionLevel.Q);
				put(4,ErrorCorrectionLevel.H);
			}
		};
		
		public QRCodeHelper(){}
		
		private static BufferedImage toBufferedImage(BitMatrix matrix,String logoPath) { 
			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); 
			     } 
			 } 
			 try {
			     if(logoPath!=null&&(logoPath.length()>0)){
			    	  insertImage(image, logoPath, true);
			     }
			  } catch (Exception e) {
				 // TODO Auto-generated catch block
				 e.printStackTrace();
			  }
			  return image; 
	     } 
		    
		      
		 private static void writeToFile(BitMatrix matrix, String format, File file,String logoPath) 
		       throws IOException { 
		     BufferedImage image = toBufferedImage(matrix,logoPath); 
		     if (!ImageIO.write(image, format, file)) { 
		       throw new IOException("Could not write an image of format " + format + " to " + file); 
		     } 
		  } 
		    
		      
		  private static void writeToStream(BitMatrix matrix, String format, OutputStream stream,String logoPath) 
		       throws IOException { 
		     BufferedImage image = toBufferedImage(matrix,logoPath); 
		     if (!ImageIO.write(image, format, stream)) { 
		       throw new IOException("Could not write an image of format " + format); 
		     } 
		   }	
		   
		   
		   /** 
		     * 插入LOGO 
		     *  
		     * @param source 
		     *            二维码图片 
		     * @param imgPath 
		     *            LOGO图片地址 
		     * @param needCompress 
		     *            是否压缩 
		     * @throws Exception 
		     */  
		    private static void insertImage(BufferedImage source, String logoPath,  
		            boolean needCompress) throws Exception {  
		        File file = new File(logoPath);  
		        if (!file.exists()) {  
		            System.err.println(""+logoPath+"   该文件不存在！");  
		            return;  
		        }  
		        Image src = ImageIO.read(new File(logoPath));  
		        int width = src.getWidth(null);  
		        int height = src.getHeight(null);  
		        int grWidth=source.getWidth();
		        int grHeigth=source.getHeight();
		        int loginWidth=grWidth/6;
		        int loginHeight=grHeigth/6;
		        // 压缩LOGO
		        if (needCompress) {   
		            if (width > loginWidth) {  
		                width = loginWidth;  
		            }  
		            if (height > loginHeight) {  
		                height = loginHeight;  
		            }  
		            //得到一个按照指定宽度和高度缩放以后的Image实例
		            Image image = src.getScaledInstance(width, height,  
		                    Image.SCALE_SMOOTH);  
		            BufferedImage tag = new BufferedImage(width, height,  
		                    BufferedImage.TYPE_INT_RGB);  
		            Graphics g = tag.getGraphics();
		            // 绘制缩小后的图
		            g.drawImage(image, 0, 0, null); 
		            //释放此图形的上下文以及它使用的所有系统资源
		            g.dispose();  
		            src = image;  
		        }  
		        // 插入LOGO  
		        Graphics2D graph = source.createGraphics();  
		        int x = (grWidth - width) / 2;  
		        int y = (grHeigth - height) / 2;  
		        graph.drawImage(src, x, y, width, height, null);  
		        Shape shape = new RoundRectangle2D.Float(x, y, width, width, 6, 6);  
		        //设置轮廓
		        graph.setStroke(new BasicStroke(3f));  
		        graph.draw(shape);  
		        graph.dispose();  
		    }
		    
		    
		    
		    /**
		     * 生产二维码主方法
		     * @param content  二维码的内容
		     * @param width   宽度
		     * @param height  高度
		     * @param qrPath  生产的二维码图片路径
		     * @param logoPath  要添加的logo图片，不需要的话为null
		     * @param level  校验级别 1-4
		     * @throws Exception
		     */
		    public void createQRCode(String content,int width,int height,String qrPath,String logoPath,int level) throws Exception{
		    	int index=qrPath.lastIndexOf(".");
		    	//二维码的图片格式 
		        String format = qrPath.substring(index+1);
		        Hashtable hints = new Hashtable(); 
		        //内容所使用编码 
		        //设置二维码排错率，可选L(7%)、M(15%)、Q(25%)、H(30%)，排错率越高可存储的信息越少，但对二维码清晰度的要求越小
		        hints.put(EncodeHintType.ERROR_CORRECTION, levelMap.get(Integer.valueOf(level)));
		        hints.put(EncodeHintType.CHARACTER_SET, "UTF-8"); 
		        BitMatrix bitMatrix = new MultiFormatWriter().encode(
		        		content,
		        		BarcodeFormat.QR_CODE, 
		        		width, 
		        		height, 
		        		hints
		        ); 
		        //生成二维码 
		        File outputFile = new File(qrPath); 
		        writeToFile(bitMatrix, format, outputFile,logoPath); 				   			    	
		    }
		    
		    public Result analyseQRCode(String qrPath) throws Exception{
		    	File file = new File(qrPath); 
		    	System.out.println(file.getName());
		    	BufferedImage bufferedImage = null; 		    		       		    			    		       
		    	bufferedImage = ImageIO.read(file);
		    	LuminanceSource source = new BufferedImageLuminanceSource(bufferedImage); 		    		       
		    	BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source)); 
		        Hashtable hints = new Hashtable(); 
		        //hints.put(EncodeHintType.ERROR_CORRECTION, levelMap.get(Integer.valueOf(level)));
		        hints.put(EncodeHintType.CHARACTER_SET, "UTF-8"); 
		        Result result = null;   		     
		        result = new MultiFormatReader().decode(bitmap, hints); 
		        return result;
		    }
}