利用zxing讀寫PDF417碼制的二維碼

項目中須要用到二維碼，二維碼的碼制是PDF417，在作了一番研究以後發現zxing是個不錯的開源工具（代碼託管在google上面）。爲何選擇zxing，因爲其餘一些工具好比barcode4j（開源，支持讀，好像不支持寫，最後維護時間在2010年）、barcode（商業版）都不太適合，因此選擇了zxing。

zxing並無提供直接可使用的jar文件，而是須要本身經過編譯源碼，生成須要的jar文件。額外說明，zxing利用maven管理本身的代碼，而且默認使用了jdk7，代碼中也使用了jdk7的一些新特性，基於這些狀況，能夠適當調整jdk的版本（若是下降jdk的版本，須要改動少許的源碼）。

下面直接貼出讀寫文件的代碼：

ZxingPdfRead

package test;

import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.net.URLDecoder;
import java.util.EnumMap;
import java.util.Map;

import javax.imageio.ImageIO;

import com.google.zxing.BinaryBitmap;
import com.google.zxing.BufferedImageLuminanceSource;
import com.google.zxing.DecodeHintType;
import com.google.zxing.LuminanceSource;
import com.google.zxing.MultiFormatReader;
import com.google.zxing.Reader;
import com.google.zxing.ReaderException;
import com.google.zxing.Result;
import com.google.zxing.common.HybridBinarizer;

public class ZxingPdfRead {
	private static Reader barcodeReader = new MultiFormatReader();

	/**
	 * @param args
	 * @throws IOException
	 */
	public static void main(String[] args) throws Exception {
		File testImage = new File(
				"E:\\work\\all_workspace\\wp_zxing\\barcode4jTest\\src\\test\\helloworld.png");

		BufferedImage image = ImageIO.read(testImage);

		LuminanceSource source = new BufferedImageLuminanceSource(image);

		BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));

		try {
			Map<DecodeHintType, Object> hints = new EnumMap<DecodeHintType, Object>(
					DecodeHintType.class);

			hints.put(DecodeHintType.TRY_HARDER, Boolean.TRUE);

			Result result = barcodeReader.decode(bitmap, hints);

			String resultText = result.getText();

			System.out.println("resultText:" + URLDecoder.decode(resultText, "UTF-8"));
		} catch (ReaderException ignored) {
			ignored.printStackTrace();
		}
	}
}

ZxingPdfWrite

package test;

import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.net.URLEncoder;

import javax.imageio.ImageIO;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.WriterException;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.pdf417.PDF417Writer;

public class ZxingPdfWrite {
	private static final int BLACK = 0xff000000;
	private static final int WHITE = 0xFFFFFFFF;

	/**
	 * @param args
	 * @throws WriterException
	 */
	public static void main(String[] args) throws Exception {
		// TODO Auto-generated method stub
		PDF417Writer pdf417Writer = new PDF417Writer();
		//注意中文亂碼問題
		BitMatrix bitMatrix = pdf417Writer.encode(URLEncoder.encode("我是中國人","UTF-8"),
				BarcodeFormat.PDF_417, 100, 50);
		
		writeToFile(bitMatrix,"png",new File("E:\\work\\all_workspace\\wp_zxing\\barcode4jTest\\src\\test\\helloworld.png"));
	}

	public static void writeToFile(BitMatrix matrix, String format, File file)
			throws IOException {
		BufferedImage image = toBufferedImage(matrix);
		ImageIO.write(image, format, file);
	}

	public static BufferedImage toBufferedImage(BitMatrix matrix) {
		int width = matrix.getWidth();
		int height = matrix.getHeight();
		BufferedImage image = new BufferedImage(width, height,
				BufferedImage.TYPE_INT_ARGB);
		for (int x = 0; x < width; x++) {
			for (int y = 0; y < height; y++) {
				image.setRGB(x, y, matrix.get(x, y) == true ? BLACK : WHITE);
			}
		}
		return image;
	}

}