package cn.qrcode;

import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.io.File;
import java.util.HashMap;
import java.util.Map;

import javax.imageio.ImageIO;

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.decoder.ErrorCorrectionLevel;
import com.google.zxing.qrcode.decoder.Mode;
import com.google.zxing.qrcode.decoder.Version;
import com.google.zxing.qrcode.encoder.QRCode;

public class QRTest2 {

	public static void main(String[] args) {
		try {
			createImage("hello world!", "src/a.png", 200, 200);
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	/**
	 * @param contents 字符串内容
	 * @param width 宽度
	 * @param height  高度
	 * @param imgPath 图片输出路径
	 */
	public void encode(String contents, int width, int height, String imgPath) {
		Map<EncodeHintType, Object> hints = new HashMap<EncodeHintType, Object>();
		// 指定纠错等级
		hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.M);
		// 指定编码格式
		hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
		try {
			BitMatrix bitMatrix = new MultiFormatWriter().encode(contents, BarcodeFormat.QR_CODE, width, height, hints);
			MatrixToImageWriter.writeToFile(bitMatrix, "png", new File(imgPath));
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	/**
	 * @param sms_info 信息内容
	 * @param filePath 输出路径
	 * @param width 宽度
	 * @param height 高度
	 * @throws Exception
	 */
	public static void createImage(String sms_info, String filePath, int width,
			int height) throws Exception {
		try {
			QRCode qrCode = new QRCode();
			qrCode.setECLevel(ErrorCorrectionLevel.M);
			qrCode.setMode(Mode.BYTE);
			qrCode.setVersion(Version.getVersionForNumber(7));
			String testString = sms_info;
			byte[] d = testString.getBytes("UTF-8");
			System.out.println(d.length);
			
			// 限制最大字节数为120
			if (d.length > 0 && d.length < 120) {
				boolean[][] s = new boolean[10][15];
				BufferedImage bi = new BufferedImage(s.length, s[0].length, BufferedImage.TYPE_BYTE_BINARY);
				Graphics2D g = bi.createGraphics();
				g.setBackground(Color.WHITE);
				g.clearRect(0, 0, s.length, s[0].length);
				g.setColor(Color.BLACK);
				int mulriple = 1;
				for (int i = 0; i < s.length; i++) {
					for (int j = 0; j < s.length; j++) {
						if (s[j][i]) {
							g.fillRect(j * mulriple, i * mulriple, mulriple, mulriple);
						}
					}
				}
				g.dispose();
				bi.flush();
				File f = new File(filePath);
				if (!f.exists()) {
					f.createNewFile();
				}
				bi = resize(bi, width, height);
				// 创建图片
				ImageIO.write(bi, "png", f);
			}
		} catch (Exception e) {
			e.printStackTrace();
		}

	}

	/**
	 * 图像缩放
	 * 
	 * @param source
	 * @param targetW
	 * @param targetH
	 * @return
	 */
	private static BufferedImage resize(BufferedImage source, int targetW, int targetH) {
		int type = source.getType();
		BufferedImage target = null;
		double sx = (double) targetW / source.getWidth();
		double sy = (double) targetH / source.getHeight();
		target = new BufferedImage(targetW, targetH, type);
		Graphics2D g = target.createGraphics();
		g.drawRenderedImage(source, AffineTransform.getScaleInstance(sx, sy));
		g.dispose();
		return target;
	}
}