二维码的编码与解码辅助类

需要的jar包：QRCode.jar

效果图：

以下为我封装的辅助类，提供的API只有：

(1)encode(String str);

(2)encode(String str,File f);

(3)encode(String str,OutputStream out);

(4)decode(File f);

(5)decode(InputStream in);

package org.xiazdong;

import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.InputStream;
import java.io.OutputStream;
import javax.imageio.ImageIO;
import jp.sourceforge.qrcode.QRCodeDecoder;
import jp.sourceforge.qrcode.data.QRCodeImage;
import com.swetake.util.Qrcode;

public final class QRCodeUtils {
	private QRCodeUtils() {
	}

	public static BufferedImage encode(String str) throws Exception {
		// 1. 创建Qrcode
		Qrcode qrcode = new Qrcode();
		qrcode.setQrcodeErrorCorrect('M');
		qrcode.setQrcodeEncodeMode('B');
		qrcode.setQrcodeVersion(7);
		// 2.数字以UTF-8编码
		byte[] d = str.getBytes("UTF-8");
		BufferedImage image = new BufferedImage(139, 139,
				BufferedImage.TYPE_INT_RGB);
		Graphics2D g = image.createGraphics();
		g.setBackground(Color.WHITE);
		g.clearRect(0, 0, 139, 139);
		g.setColor(Color.BLACK);
		// 3.构造二维码图片
		if (d.length > 0 && d.length < 123) {
			boolean[][] b = qrcode.calQrcode(d);
			for (int i = 0; i < b.length; i++) {
				for (int j = 0; j < b.length; j++) {
					if (b[j][i]) {
						g.fillRect(j * 3 + 2, i * 3 + 2, 3, 3);
					}
				}
			}
		}
		g.dispose();
		image.flush();
		return image;
	}

	public static void encode(String str, File f) throws Exception {
		// 1. 创建Qrcode
		Qrcode qrcode = new Qrcode();
		qrcode.setQrcodeErrorCorrect('M');
		qrcode.setQrcodeEncodeMode('B');
		qrcode.setQrcodeVersion(7);
		// 2.数字以UTF-8编码
		byte[] d = str.getBytes("UTF-8");
		BufferedImage image = new BufferedImage(139, 139,
				BufferedImage.TYPE_INT_RGB);
		Graphics2D g = image.createGraphics();
		g.setBackground(Color.WHITE);
		g.clearRect(0, 0, 139, 139);
		g.setColor(Color.BLACK);
		// 3.构造二维码图片
		if (d.length > 0 && d.length < 123) {
			boolean[][] b = qrcode.calQrcode(d); // 计算二位布尔数组
			for (int i = 0; i < b.length; i++) {
				for (int j = 0; j < b.length; j++) {
					if (b[j][i]) {
						g.fillRect(j * 3 + 2, i * 3 + 2, 3, 3); // 根据布尔数组填充图片的各点
					}
				}
			}
		}
		g.dispose();
		image.flush();
		ImageIO.write(image, "png", f);
	}

	public static void encode(String str, OutputStream out) throws Exception {
		// 1. 创建Qrcode
		Qrcode qrcode = new Qrcode();
		qrcode.setQrcodeErrorCorrect('M');
		qrcode.setQrcodeEncodeMode('B');
		qrcode.setQrcodeVersion(7);
		// 2.数字以UTF-8编码
		byte[] d = str.getBytes("UTF-8");
		BufferedImage image = new BufferedImage(139, 139,
				BufferedImage.TYPE_INT_RGB);
		Graphics2D g = image.createGraphics();
		g.setBackground(Color.WHITE);
		g.clearRect(0, 0, 139, 139);
		g.setColor(Color.BLACK);
		// 3.构造二维码图片
		if (d.length > 0 && d.length < 123) {
			boolean[][] b = qrcode.calQrcode(d);
			for (int i = 0; i < b.length; i++) {
				for (int j = 0; j < b.length; j++) {
					if (b[j][i]) {
						g.fillRect(j * 3 + 2, i * 3 + 2, 3, 3);
					}
				}
			}
		}
		g.dispose();
		image.flush();
		ImageIO.write(image, "png", out);
	}

	public static String decode(File f) throws Exception {
		QRCodeDecoder decoder = new QRCodeDecoder();
		BufferedImage image = null;
		image = ImageIO.read(f); // 获得BufferedImage
		String decodedData = new String(decoder.decode(new MyImage(image)), // 解码，并生成字符串
				"UTF-8");
		return decodedData;
	}

	public static String decode(InputStream in) throws Exception {
		QRCodeDecoder decoder = new QRCodeDecoder();
		BufferedImage image = null;
		image = ImageIO.read(in);
		String decodedData = new String(decoder.decode(new MyImage(image)),
				"UTF-8");
		return decodedData;
	}
}

class MyImage implements QRCodeImage {
	BufferedImage image;

	public MyImage(BufferedImage image) {
		this.image = image;
	}

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

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

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

}

测试类：

package test;

import java.io.File;

import org.xiazdong.QRCodeUtils;

public class Test {

	public static void main(String[] args) throws Exception {
		QRCodeUtils.encode("xiazdong", new File("1.png"));
		String str = QRCodeUtils.decode(new File("1.png"));
		System.out.println(str);
	}
}

参考文章：

(1) http://blog.csdn.net/wangpeng047/article/details/7181217

(2) http://zjgzpc.iteye.com/blog/1478106