java 生成二维码（利用google的jar包）

import com.google.zxing.BarcodeFormat;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.qrcode.QRCodeWriter;
import org.junit.Test;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.File;

// 测试二维码生成
public class QrCodeTest {

    @Test
    public void testGenerate() throws Exception {
        QRCodeWriter writer = new QRCodeWriter();
        int width = 400;
        int height = 400;
        BitMatrix bitMatrix = writer.encode("http://www.baidu.com", BarcodeFormat.QR_CODE, width, height);
        BufferedImage image = new BufferedImage(bitMatrix.getWidth(), bitMatrix.getHeight(), BufferedImage.TYPE_3BYTE_BGR);
        for (int i = 0; i < width; i++) {
            for (int j = 0; j < height; j++) {
                image.setRGB(i,j,  bitMatrix.get(i,j) ? Color.BLACK.getRGB(): Color.white.getRGB());
            }
        }
        File file = new File("./test.jpg");
        System.out.println(file.getAbsolutePath());
        ImageIO.write(image, "jpg", file);
    }

}