java读写条形码、二维码

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前言

这里讲解一下条形码与二维码的基础知识与应用.

目录:

概念

条形码(barcode)

• 以一组宽度不同的黑条和空白,安照一定编码规则,用来表示一组信息的图形标识.
• 标识一串数字或字母.
• 一般容量小于30个数字或字母

二维码(QRcode)

• 又叫二维条形码.
• 用特定的几何图形按照一定规律在平面上分布的黑白相间的图形.
• 能够存储数字,字母,汉字,图片等.
• 字符集128个字符
• 可存储<几十kb
• 抗损坏

实践

常用类包

名称	特点
Zxing(Google)	支持1D,2D的barcode
Barcode4J	纯java生成,只负责生成,不负责解析

Zxing

Maven依赖

<dependency>
    <groupId>com.google.zxing</groupId>
    <artifactId>javase</artifactId>
    <version>3.3.3</version>
</dependency>

条形码

	/**
	 * generateCode 根据code生成相应的一维码
	 * @param file 一维码目标文件
	 * @param code 一维码内容
	 * @param width 图片宽度
	 * @param height 图片高度
	 */
    public static void generateCode(File file, String code, int width, int height) {
    	//定义位图矩阵BitMatrix
        BitMatrix matrix = null;
        try {
            // 使用code_128格式进行编码生成100*25的条形码
        	MultiFormatWriter writer = new MultiFormatWriter();

            matrix = writer.encode(code,BarcodeFormat.CODE_128, width, height, null);
            //matrix = writer.encode(code,BarcodeFormat.EAN_13, width, height, null);
        } catch (WriterException e) {
            e.printStackTrace();
        }

        //将位图矩阵BitMatrix保存为图片
        try (FileOutputStream outStream = new FileOutputStream(file)) {
            ImageIO.write(MatrixToImageWriter.toBufferedImage(matrix), "png",
                    outStream);
            outStream.flush();
        } catch (Exception e) {
        	e.printStackTrace();
        }
    }

    /**
     * readCode 读取一张一维码图片
     * @param file 一维码图片名字
     */
    public static void readCode(File file){
        try {
        	BufferedImage image = ImageIO.read(file);
            if (image == null) {
                return;
            }
            LuminanceSource source = new BufferedImageLuminanceSource(image);
            BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));

            Map<DecodeHintType, Object> hints = new HashMap<>();
            hints.put(DecodeHintType.CHARACTER_SET, "GBK");
            hints.put(DecodeHintType.PURE_BARCODE, Boolean.TRUE);
            hints.put(DecodeHintType.TRY_HARDER, Boolean.TRUE);

            Result result = new MultiFormatReader().decode(bitmap, hints);
            System.out.println("条形码内容: "+result.getText());
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

二维码

	/*
     * 定义二维码的宽高
     */
    private static int WIDTH = 300;
    private static int HEIGHT = 300;
    private static String FORMAT = "png";//二维码格式

    //生成二维码
    public static void generateQRCode(File file, String content) {
        //定义二维码参数
        Map<EncodeHintType, Object> hints = new HashMap<>();

        hints.put(EncodeHintType.CHARACTER_SET, "utf-8");//设置编码
        hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.M);//设置容错等级
        hints.put(EncodeHintType.MARGIN, 2);//设置边距默认是5

        try {
            BitMatrix bitMatrix = new MultiFormatWriter().encode(content, BarcodeFormat.QR_CODE, WIDTH, HEIGHT, hints);
            Path path = file.toPath();
            MatrixToImageWriter.writeToPath(bitMatrix, FORMAT, path);//写到指定路径下

        } catch (Exception e) {
            e.printStackTrace();
        }

    }

    //读取二维码
    public static void readQrCode(File file) {
        MultiFormatReader reader = new MultiFormatReader();
        try {
            BufferedImage image = ImageIO.read(file);
            BinaryBitmap binaryBitmap = new BinaryBitmap(new HybridBinarizer(new BufferedImageLuminanceSource(image)));
            Map<DecodeHintType, Object> hints = new HashMap<>();
            hints.put(DecodeHintType.CHARACTER_SET, "utf-8");//设置编码
            Result result = reader.decode(binaryBitmap, hints);
            System.out.println("解析结果:" + result.toString());
            System.out.println("二维码格式:" + result.getBarcodeFormat());
            System.out.println("二维码文本内容:" + result.getText());
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

Barcode4J

Maven依赖

	<dependency>
	    <groupId>net.sf.barcode4j</groupId>
	    <artifactId>barcode4j</artifactId>
	    <version>2.1</version>
	</dependency>

	<dependency>
	    <groupId>org.apache.avalon.framework</groupId>
	    <artifactId>avalon-framework-api</artifactId>
	    <version>4.3.1</version>
	</dependency>

条形码

	public static void generateFile(String msg, String path) {
		File file = new File(path);
		try {
			Code39Bean bean = new Code39Bean();
			//EAN13Bean bean = new EAN13Bean();

			// dpi精度
			final int dpi = 150;
			// module宽度
			//bean.setModuleWidth(0.2);
			final double width = UnitConv.in2mm(2.0f / dpi);
			bean.setWideFactor(3);
			bean.setModuleWidth(width);
			bean.doQuietZone(false);

			String format = "image/png";
			// 输出到流
			BitmapCanvasProvider canvas = new BitmapCanvasProvider(new FileOutputStream(file), format, dpi,
					BufferedImage.TYPE_BYTE_BINARY, false, 0);

			// 生成条形码
			bean.generateBarcode(canvas, msg);

			// 结束绘制
			canvas.finish();

		} catch (Exception e) {
			e.printStackTrace();
		}
	}

二维码

public static void main(String[] args) throws Exception {

		BarcodeUtil util = BarcodeUtil.getInstance();
		BarcodeGenerator gen = util.createBarcodeGenerator(buildCfg("datamatrix"));

		OutputStream fout = new FileOutputStream("2dcode.png");
		int resolution = 300;
		BitmapCanvasProvider canvas = new BitmapCanvasProvider(fout, "image/png", resolution,
				BufferedImage.TYPE_BYTE_BINARY, false, 0);

		gen.generateBarcode(canvas, "be the coder");
		canvas.finish();
	}

	private static Configuration buildCfg(String type) {
		DefaultConfiguration cfg = new DefaultConfiguration("barcode");

		// Bar code type
		DefaultConfiguration child = new DefaultConfiguration(type);
		cfg.addChild(child);

		// Human readable text position
		DefaultConfiguration attr = new DefaultConfiguration("human-readable");
//		DefaultConfiguration subAttr = new DefaultConfiguration("placement");
//		subAttr.setValue("bottom");
//		attr.addChild(subAttr);
//		child.addChild(attr);
//		datamatrix code has no human-readable part
//		see http://barcode4j.sourceforge.net/2.1/symbol-datamatrix.html

		attr = new DefaultConfiguration("height");
		attr.setValue(50);
		child.addChild(attr);
		attr = new DefaultConfiguration("module-width");
		attr.setValue("0.6");
		child.addChild(attr);
		return cfg;
	}

总结

• 注意条形码种类
• 高并发时,注意生成速度
• api较多,需要多查询,练习

参见

• java核心技术(进阶)

标签：条形码,java,读写,DefaultConfiguration,二维码,static,file,new,hints
来源： https://blog.csdn.net/weixin_38500325/article/details/88842454