java二维码生成技术

　　自从微信扫描出世，二维码扫描逐渐已经成为一种主流的信息传递和交换方式。下面就介绍一下我学习到的这种二维码生成方式。预计再过不久身份证户口本等都会使用二维码识别了，今天就做一个实验案例；

二维码主要实现这两点：

　　1.生成任意的二维码。

　　2.在二维码的中间加入图像。

　一、准备工作。

准备QR二维码3.0 版本的core包和一张jpg图片。

下载QR二维码包。

当然你也可以从maven仓库下载jar 包: http://central.maven.org/maven2/com/google/zxing/core/

二、程序设计

1、启动eclipse，新建一个java项目，命好项目名（本例取名为QRCodeSoft）。点下一步：

2、导入zxing.jar 包, 我这里用的是3.0 版本的core包：点“添加外部JAR(X)…”。

3、新建两个类，分别是：

BufferedImageLuminanceSource.java

QRCodeUtil.java

package com.code.liu;

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;
    }

    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;
    }

    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;
    }

    public boolean isCropSupported() {
        return true;
    }

    public LuminanceSource crop(int left, int top, int width, int height) {
        return new BufferedImageLuminanceSource(image, this.left + left,
                this.top + top, width, height);
    }

    public boolean isRotateSupported() {
        return true;
    }

    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);
    }
}

package com.code.liu;

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.OutputStream;
import java.util.Hashtable;
import java.util.Random;

import javax.imageio.ImageIO;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.BinaryBitmap;
import com.google.zxing.DecodeHintType;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatReader;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.Result;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.common.HybridBinarizer;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;

/**
 * 二维码工具类
 *
 */
public class QRCodeUtil {

    private static final String CHARSET = "utf-8";
    private static final String FORMAT_NAME = "JPG";
    // 二维码尺寸
    private static final int QRCODE_SIZE = 300;
    // LOGO宽度
    private static final int WIDTH = 60;
    // LOGO高度
    private static final int HEIGHT = 60;

    private static BufferedImage createImage(String content, String imgPath,
            boolean needCompress) throws Exception {
        Hashtable<EncodeHintType, Object> hints = new Hashtable<EncodeHintType, Object>();
        hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
        hints.put(EncodeHintType.CHARACTER_SET, CHARSET);
        hints.put(EncodeHintType.MARGIN, 1);
        BitMatrix bitMatrix = new MultiFormatWriter().encode(content,
                BarcodeFormat.QR_CODE, QRCODE_SIZE, QRCODE_SIZE, hints);
        int width = bitMatrix.getWidth();
        int height = bitMatrix.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, bitMatrix.get(x, y) ? 0xFF000000
                        : 0xFFFFFFFF);
            }
        }
        if (imgPath == null || "".equals(imgPath)) {
            return image;
        }
        // 插入图片
        QRCodeUtil.insertImage(image, imgPath, needCompress);
        return image;
    }

    /**
     * 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 imgPath,
            boolean needCompress) throws Exception {
        File file = new File(imgPath);
        if (!file.exists()) {
            System.err.println(""+imgPath+"   该文件不存在！");
            return;
        }
        Image src = ImageIO.read(new File(imgPath));
        int width = src.getWidth(null);
        int height = src.getHeight(null);
        if (needCompress) { // 压缩LOGO
            if (width > WIDTH) {
                width = WIDTH;
            }
            if (height > HEIGHT) {
                height = HEIGHT;
            }
            Image image = src.getScaledInstance(width, height,
                    Image.SCALE_SMOOTH);
            BufferedImage tag = new BufferedImage(width, height,
                    BufferedImage.TYPE_INT_RGB);
            Graphics g = tag.getGraphics();
            g.drawImage(image, 0, 0, null); // 绘制缩小后的图
            g.dispose();
            src = image;
        }
        // 插入LOGO
        Graphics2D graph = source.createGraphics();
        int x = (QRCODE_SIZE - width) / 2;
        int y = (QRCODE_SIZE - height) / 2;
        graph.drawImage(src, x, y, width, height, null);
        Shape shape = new RoundRectangle2D.Float(x, y, width, width, 6, 6);
        graph.setStroke(new BasicStroke(3f));
        graph.draw(shape);
        graph.dispose();
    }

    /**
     * 生成二维码(内嵌LOGO)
     *
     * @param content
     *            内容
     * @param imgPath
     *            LOGO地址
     * @param destPath
     *            存放目录
     * @param needCompress
     *            是否压缩LOGO
     * @throws Exception
     */
    public static void encode(String content, String imgPath, String destPath,
            boolean needCompress) throws Exception {
        BufferedImage image = QRCodeUtil.createImage(content, imgPath,
                needCompress);
        mkdirs(destPath);
        String file = new Random().nextInt(99999999)+".jpg";
        ImageIO.write(image, FORMAT_NAME, new File(destPath+"/"+file));
    }

    /**
     * 当文件夹不存在时，mkdirs会自动创建多层目录，区别于mkdir．(mkdir如果父目录不存在则会抛出异常)
     * @author lanyuan
     * Email: mmm333zzz520@163.com
     * @date 2013-12-11 上午10:16:36
     * @param destPath 存放目录
     */
    public static void mkdirs(String destPath) {
        File file =new File(destPath);
        //当文件夹不存在时，mkdirs会自动创建多层目录，区别于mkdir．(mkdir如果父目录不存在则会抛出异常)
        if (!file.exists() && !file.isDirectory()) {
            file.mkdirs();
        }
    }

    /**
     * 生成二维码(内嵌LOGO)
     *
     * @param content
     *            内容
     * @param imgPath
     *            LOGO地址
     * @param destPath
     *            存储地址
     * @throws Exception
     */
    public static void encode(String content, String imgPath, String destPath)
            throws Exception {
        QRCodeUtil.encode(content, imgPath, destPath, false);
    }

    /**
     * 生成二维码
     *
     * @param content
     *            内容
     * @param destPath
     *            存储地址
     * @param needCompress
     *            是否压缩LOGO
     * @throws Exception
     */
    public static void encode(String content, String destPath,
            boolean needCompress) throws Exception {
        QRCodeUtil.encode(content, null, destPath, needCompress);
    }

    /**
     * 生成二维码
     *
     * @param content
     *            内容
     * @param destPath
     *            存储地址
     * @throws Exception
     */
    public static void encode(String content, String destPath) throws Exception {
        QRCodeUtil.encode(content, null, destPath, false);
    }

    /**
     * 生成二维码(内嵌LOGO)
     *
     * @param content
     *            内容
     * @param imgPath
     *            LOGO地址
     * @param output
     *            输出流
     * @param needCompress
     *            是否压缩LOGO
     * @throws Exception
     */
    public static void encode(String content, String imgPath,
            OutputStream output, boolean needCompress) throws Exception {
        BufferedImage image = QRCodeUtil.createImage(content, imgPath,
                needCompress);
        ImageIO.write(image, FORMAT_NAME, output);
    }

    /**
     * 生成二维码
     *
     * @param content
     *            内容
     * @param output
     *            输出流
     * @throws Exception
     */
    public static void encode(String content, OutputStream output)
            throws Exception {
        QRCodeUtil.encode(content, null, output, false);
    }

    /**
     * 解析二维码
     *
     * @param file
     *            二维码图片
     * @return
     * @throws Exception
     */
    public static String decode(File file) throws Exception {
        BufferedImage image;
        image = ImageIO.read(file);
        if (image == null) {
            return null;
        }
        BufferedImageLuminanceSource source = new BufferedImageLuminanceSource(
                image);
        BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));
        Result result;
        Hashtable<DecodeHintType, Object> hints = new Hashtable<DecodeHintType, Object>();
        hints.put(DecodeHintType.CHARACTER_SET, CHARSET);
        result = new MultiFormatReader().decode(bitmap, hints);
        String resultStr = result.getText();
        return resultStr;
    }

    /**
     * 解析二维码
     *
     * @param path
     *            二维码图片地址
     * @return
     * @throws Exception
     */
    public static String decode(String path) throws Exception {
        return QRCodeUtil.decode(new File(path));
    }

    public static void main(String[] args) throws Exception {
        String text = "http://www.cnblogs.com/qianxiaoruofeng/";
        QRCodeUtil.encode(text, "c:/Users/Administrator/Desktop/liupeng/1.png", "c:/Users/Administrator/Desktop/liupeng/barcode", true);
    }
}

生成不带logo 的二维码

程序代码

public static void main(String[] args) throws Exception {
        String text = "http://www.cnblogs.com/qianxiaoruofeng/";

QRCodeUtil.encode(text,"", "c:/Users/Administrator/Desktop/liupeng/barcode",true);

}

运行这个测试方法，生成的二维码不带 logo , 样式如下:

有兴趣可以用手机扫描一下

生成带logo 的二维码 
logo 可以用自己的头像，或者自己喜欢的一个图片都可以 , 采用如下代码

程序代码

public static void main(String[] args) throws Exception {
        String text = "http://www.cnblogs.com/qianxiaoruofeng/";

      QRCodeUtil.encode(text, "c:/Users/Administrator/Desktop/liupeng/1.png", "c:/Users/Administrator/Desktop/liupeng/barcode", true);

    }

唯一的区别是，在前面的基础上指定了logo 的地址，这里测试都用了C盘的图片文件

手机扫描二维码进入浅笑若风的博客。