java生成二维码，具体代码如下所示：

package com.bus.wx.action.code;import java.awt.BasicStroke;import java.awt.Color;import java.awt.Graphics2D;import java.awt.RenderingHints;import java.awt.geom.RoundRectangle2D;import java.awt.image.BufferedImage;import java.io.ByteArrayInputStream;import java.io.ByteArrayOutputStream;import java.io.File;import java.io.IOException;import java.io.InputStream;import java.util.HashMap;import java.util.Hashtable;import java.util.Map;import javax.imageio.ImageIO;import javax.servlet.ServletOutputStream;import org.springframework.context.annotation.Scope;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.PathVariable;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestMethod;import sun.misc.BASE64Decoder;import sun.misc.BASE64Encoder;import com.bus.plugin.wx.action.WxAction;import com.bus.wx.util.Limits;import com.google.zxing.BarcodeFormat;import com.google.zxing.EncodeHintType;import com.google.zxing.MultiFormatWriter;import com.google.zxing.client.j2se.MatrixToImageWriter;import com.google.zxing.common.BitMatrix;import com.google.zxing.qrcode.QRCodeWriter;import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;import com.lys.sys.log.Log;/** * 条形码、二维码 * @author hwj * */@Scope(value = "prototype")@Controller("Bar_Qr_Code_Action")@RequestMapping(value="plug/wx/wwz/{bcflag}/barqrcode")public class Bar_Qr_Code_Action extends WxAction{ private static final int LogoPart = 4; private static final int BLACK = 0xFF000000;//用于设置图案的颜色   private static final int WHITE = 0xFFFFFFFF; //用于背景色   String format = "png";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)); //     image.setRGB(x, y, (matrix.get(x, y) ? Color.YELLOW.getRGB() : Color.CYAN.getRGB()));     }   }   return image; }  public BufferedImage LogoMatrix(BufferedImage matrixImage) throws IOException{      /**       * 读取二维码图片，并构建绘图对象       */      Graphics2D g2 = matrixImage.createGraphics();            int matrixWidth = matrixImage.getWidth();      int matrixHeigh = matrixImage.getHeight();            /**       * 读取Logo图片       */      String path=request.getSession().getServletContext().getRealPath("/images/logo/dzjkklog.png");     BufferedImage logo = ImageIO.read(new File(path));        //开始绘制图片      g2.drawImage(logo,matrixWidth/5*2,matrixHeigh/5*2, matrixWidth/5, matrixHeigh/5, null);//绘制         BasicStroke stroke = new BasicStroke(5,BasicStroke.CAP_ROUND,BasicStroke.JOIN_ROUND);       g2.setStroke(stroke);// 设置笔画对象      //指定弧度的圆角矩形      RoundRectangle2D.Float round = new RoundRectangle2D.Float(matrixWidth/5*2, matrixHeigh/5*2, matrixWidth/5, matrixHeigh/5,20,20);      g2.setColor(Color.white);      g2.draw(round);// 绘制圆弧矩形            //设置logo 有一道灰色边框      BasicStroke stroke2 = new BasicStroke(1,BasicStroke.CAP_ROUND,BasicStroke.JOIN_ROUND);       g2.setStroke(stroke2);// 设置笔画对象      RoundRectangle2D.Float round2 = new RoundRectangle2D.Float(matrixWidth/5*2+2, matrixHeigh/5*2+2, matrixWidth/5-4, matrixHeigh/5-4,20,20);      g2.setColor(new Color(128,128,128));      g2.draw(round2);// 绘制圆弧矩形            g2.dispose();      matrixImage.flush() ;      return matrixImage ;    }       /** * 生成二维码：直接将生成的二维码传输到前台页面 * @param bcflag */ @RequestMapping(value="createQrCodes",method = RequestMethod.GET) public void createQrCodes(@PathVariable String bcflag,String dastid){  String url="扫二维码出现的内容"; if(url!=null&&!"".equals(url)){  ServletOutputStream stream=null;  try {  int width=430;  int height=430;  stream=response.getOutputStream();  QRCodeWriter writer=new QRCodeWriter();   Hashtable hints = new Hashtable();            hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);       hints.put(EncodeHintType.CHARACTER_SET, "utf-8");         hints.put(EncodeHintType.MARGIN, 1);//设置二维码边的空度，非负数       BitMatrix bitMatrix = new MultiFormatWriter().encode(url,//要编码的内容           BarcodeFormat.QR_CODE,           width, //条形码的宽度           height, //条形码的高度           hints);  //BitMatrix m=writer.encode(url, BarcodeFormat.QR_CODE, height,width);   BufferedImage image = toBufferedImage(bitMatrix);     image = LogoMatrix(image);      if (!ImageIO.write(image, format, stream)) {        throw new IOException("Could not write an image of format " + format);      }   } catch (Exception e) {   Log.in.info(e.getMessage());  }finally{   if(stream!=null){   try {    stream.flush();    stream.close();    } catch (IOException e) {    Log.in.info(e.getMessage());    }   }  }  } }}