涉及到的一些主要类库，方便大家下载：

• 二维码编码lib:Qrcode_swetake.jar（官网介绍 -- http://www.swetake.com/qr/index-e.html）
  
• 二维码解码lib:qrcode.jar （官网介绍 -- http://sourceforge.jp/projects/qrcode/）

java二维码 生成二维码 QRCodeEncoderHandler.java

import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.File;

import javax.imageio.ImageIO;

import com.swetake.util.Qrcode;

/**
 * 二维码生成器
 * @blog http://zhblog.github.com/blog
 * @author zzh
 */
public class QRCodeEncoderHandler {

    /**
     * 生成二维码(QRCode)图片
     * @param content
     * @param imgPath
     */
    public void encoderQRCode(String content, String imgPath) {
        try {

            Qrcode qrcodeHandler = new Qrcode();
            qrcodeHandler.setQrcodeErrorCorrect('M');
            qrcodeHandler.setQrcodeEncodeMode('B');
            qrcodeHandler.setQrcodeVersion(7);

            System.out.println(content);
            byte[] contentBytes = content.getBytes("utf-8");

            BufferedImage bufImg = new BufferedImage(140, 140,
                    BufferedImage.TYPE_INT_RGB);

            Graphics2D gs = bufImg.createGraphics();

            gs.setBackground(Color.cyan);
            gs.clearRect(0, 0, 140, 140);

            // 设定图像颜色 > BLACK
            gs.setColor(Color.BLACK);

            // 设置偏移量 不设置可能导致解析出错
            int pixoff = 2;
            // 输出内容 > 二维码
            if (contentBytes.length > 0 && contentBytes.length < 120) {
                boolean[][] codeOut = qrcodeHandler.calQrcode(contentBytes);
                for (int i = 0; i < codeOut.length; i++) {
                    for (int j = 0; j < codeOut.length; j++) {
                        if (codeOut[j][i]) {
                            gs.fillRect(j * 3 + pixoff, i * 3 + pixoff, 3, 3);
                        }
                    }
                }
            } else {
                System.err.println("QRCode content bytes length = "
                        + contentBytes.length + " not in [ 0,120 ]. ");
            }

            gs.dispose();
            bufImg.flush();

            File imgFile = new File(imgPath);

            // 生成二维码QRCode图片
            ImageIO.write(bufImg, "png", imgFile);

        } catch (Exception e) {
            e.printStackTrace();
        }

    }

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        String imgPath = "./zzh.png";

        String content = "\t江湖在喝酒的路上"
                + "\nMyblog  :http://zhblog.github.com/blog"
                + "\nEMail   :jack.zh.1986@gmail.com"
                + "\nQQ      :715443050";

        QRCodeEncoderHandler handler = new QRCodeEncoderHandler();
        handler.encoderQRCode(content, imgPath);
        System.out.println("encoder QRcode success");
    }
}

java二维码解码 QRCodeDecoderHandler.java

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

import javax.imageio.ImageIO;

import jp.sourceforge.qrcode.QRCodeDecoder;
import jp.sourceforge.qrcode.data.QRCodeImage;
import jp.sourceforge.qrcode.exception.DecodingFailedException;

/**
 * @blog http://zhblog.github.com/blog
 * @author zzh
 */
public class QRCodeDecoderHandler {

    /**
     * 解码二维码
     * @param imgPath
     * @return String
     */
    public String decoderQRCode(String imgPath) {

        // QRCode 二维码图片的文件
        File imageFile = new File(imgPath);

        BufferedImage bufImg = null;
        String decodedData = null;
        try {
            bufImg = ImageIO.read(imageFile);

            QRCodeDecoder decoder = new QRCodeDecoder();
            decodedData = new String(decoder.decode(new J2SEImage(bufImg)));
        } catch (IOException e) {
            System.out.println("Error: " + e.getMessage());
            e.printStackTrace();
        } catch (DecodingFailedException dfe) {
            System.out.println("Error: " + dfe.getMessage());
            dfe.printStackTrace();
        }
        return decodedData;
    }

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        QRCodeDecoderHandler handler = new QRCodeDecoderHandler();
        String imgPath = "zzh.png";
        String decoderContent = handler.decoderQRCode(imgPath);
        System.out.println("解析结果如下：");
        System.out.println(decoderContent);
        System.out.println("========decoder success!!!");
    }

    class J2SEImage implements QRCodeImage {
        BufferedImage bufImg;

        public J2SEImage(BufferedImage bufImg) {
            this.bufImg = bufImg;
        }

        public int getWidth() {
            return bufImg.getWidth();
        }

        public int getHeight() {
            return bufImg.getHeight();
        }

        public int getPixel(int x, int y) {
            return bufImg.getRGB(x, y);
        }

    }
}