java 生成二维码图片

需下载jar
jar路径：http://files.cnblogs.com/files/liaolongjun/qrcode.zip

package com.example.demo;

import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.io.OutputStream;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import javax.imageio.ImageIO;
import javax.swing.filechooser.FileSystemView;
import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.common.BitMatrix;

/**
 * 生成二维码图片

 * 
Title: QrCodeUtil
 
 * 
 * 
Description: 
  
 *
 *                    _ooOoo_
 *                   o8888888o
 *                   88" . "88
 *                   (| -_- |)
 *                    O\ = /O
 *                ____/`---'\____
 *              .   ' \\| |// `.
 *               / \\||| : |||// \
 *             / _||||| -:- |||||- \
 *               | | \\\ - /// | |
 *             | \_| ''\---/'' | |
 *              \ .-\__ `-` ___/-. /
 *           ___`. .' /--.--\ `. . __
 *        ."" '< `.___\_<|>_/___.' >'"".
 *       | | : `- \`.;`\ _ /`;.`/ - ` : | |
 *         \ \ `-. \_ __\ /__ _/ .-` / /
 * ======`-.____`-.___\_____/___.-`____.-'======
 *                    `=---='
 *
 * .............................................
   *         佛祖保佑             永无BUG
 *
 *
 * @author Administrator  

 * @date 2019年6月19日
 */
public class QrCodeUtil
{
	public static void main(String[] args)
	{
		String url = "https://blog.csdn.net/m0_37847558";
		//path 二维码存放路径
		String path = FileSystemView.getFileSystemView().getHomeDirectory() + File.separator + "testQrcode";
		//fileName 二维码图片名称
		String fileName = new SimpleDateFormat("yyyyMMddHHmmss").format(new Date()) + ".jpg";
		createQrCode(url, path, fileName);
	}

	public static String createQrCode(String url, String path, String fileName)
	{
		try
		{
			Map hints = new HashMap<>();
			hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
			BitMatrix bitMatrix = new MultiFormatWriter().encode(url, BarcodeFormat.QR_CODE, 400, 400, hints);
			File file = new File(path, fileName);
			if (file.exists()
					|| ((file.getParentFile().exists() || file.getParentFile().mkdirs()) && file.createNewFile()))
			{
				writeToFile(bitMatrix, "jpg", file);
				System.out.println("搞定：" + file);
			}
		} catch (Exception e)
		{
			e.printStackTrace();
		}
		return null;
	}

	static void writeToFile(BitMatrix matrix, String format, File file) throws IOException
	{
		BufferedImage image = toBufferedImage(matrix);
		if (!ImageIO.write(image, format, file))
		{
			throw new IOException("Could not write an image of format " + format + " to " + file);
		}
	}

	static void writeToStream(BitMatrix matrix, String format, OutputStream stream) throws IOException
	{
		BufferedImage image = toBufferedImage(matrix);
		if (!ImageIO.write(image, format, stream))
		{
			throw new IOException("Could not write an image of format " + format);
		}
	}

	private static final int BLACK = 0xFF000000;
	private static final int WHITE = 0xFFFFFFFF;

	private 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);
			}
		}
		return image;
	}
}

转载来源:https://faceghost.com/article/313711