java使用google.zxing生成二维码

1、maven依赖

<dependency>
    <groupId>com.google.zxing</groupId>
    <artifactId>core</artifactId>
    <version>3.3.1</version>
</dependency>
<dependency>
    <groupId>com.google.zxing</groupId>
    <artifactId>javase</artifactId>
    <version>3.3.0</version>
</dependency>

2、生成方式

2.1 无需保存图片版

使用后台生成byte[]的方式传到前台进行展示，前台使用js进行解析

2.1.1 java代码

@RequestMapping({ "QRcode" })
@ResponseBody
public String QRcode(HttpServletRequest request){
	byte[] QRcode=QRManager.getQRcode();
	//返回前台一个String串
	return Arrays.toString(QRcode);
}

public byte[] getQRcode(){
	byte[] pngData =null;
	try {
		QRCodeWriter qrCodeWriter = new QRCodeWriter();
		Map<EncodeHintType, Object> hints = new HashMap<EncodeHintType, Object>();
		//使中文不乱码
		hints.put(EncodeHintType.CHARACTER_SET, "utf-8"); 
		String content="";
		content+="姓名：张三\n";
		content+="性别：男\n";
		//BarcodeFormat.QR_CODE：编码格式
		//300，300：分别是生成的二维码的宽高
		BitMatrix bitMatrix = qrCodeWriter.encode(content, BarcodeFormat.QR_CODE, 300, 300,hints);
		ByteArrayOutputStream pngOutputStream = new ByteArrayOutputStream();
		MatrixToImageWriter.writeToStream(bitMatrix, "PNG", pngOutputStream);
		pngData = pngOutputStream.toByteArray();
	}catch (Exception e){
		LOG.warn(e.getMessage());
	}
	return pngData;
}

2.2.1 前台解析

<img id="QRcodeImg" src="">

$(function () {
	 $.ajax({
        url:__rootPath+'/QRcode.do',
        method:'POST',
        success: function (bytesStr) {
			//因为返回的格式为[-21,1,.........] 所以要把前后的[]去掉
            bytesStr=bytesStr.substring(1,bytesStr.length-1);
            var bytes = new Uint8Array(bytesStr.split(","));
            var blob = new Blob([bytes], { type: "image/png" });
            var url = URL.createObjectURL(blob);
            document.getElementById('QRcodeImg').src = url;
        }
    });
})

2.1.3 生成的二维码