程序員在上海之四

今天主要分享下前段時間做微信二維碼的一些問題,我們都知道二維碼的生產可以放到java後端,也可以直接使用jQuery插件jquery.qrcode.min.js來簡單實現。下面簡單分享下兩種方式:

    1、java代碼生產二維碼。

       具體實現如下:

import java.awt.BasicStroke;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Shape;
import java.awt.geom.RoundRectangle2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.OutputStream;
import java.util.Hashtable;

import javax.imageio.ImageIO;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.BinaryBitmap;
import com.google.zxing.DecodeHintType;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatReader;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.Result;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.common.HybridBinarizer;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
/**
 * 
 * @author ****
 *
 */
public class QRCodeUtil {
private static final String CHARSET = "utf-8";
private static final String FORMAT_NAME = "png";
// 二維碼尺寸
private static final int QRCODE_SIZE = 300;
// LOGO寬度
private static final int WIDTH = 60;
// LOGO高度
private static final int HEIGHT = 60;

private static BufferedImage createImage(String content, String imgPath,
        boolean needCompress) throws Exception {
    Hashtable hints = new Hashtable();
    hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
    hints.put(EncodeHintType.CHARACTER_SET, CHARSET);
    hints.put(EncodeHintType.MARGIN, 1);
    BitMatrix bitMatrix = new MultiFormatWriter().encode(content,
            BarcodeFormat.QR_CODE, QRCODE_SIZE, QRCODE_SIZE, hints);
    int width = bitMatrix.getWidth();
    int height = bitMatrix.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, bitMatrix.get(x, y) ? 0xFF000000
                    : 0xFFFFFFFF);
        }
    }
    if (imgPath == null || "".equals(imgPath)) {
        return image;
    }
    // 插入圖片
    QRCodeUtil.insertImage(image, imgPath, needCompress);
    return image;
}


private static void insertImage(BufferedImage source, String imgPath,
        boolean needCompress) throws Exception {
    File file = new File(imgPath);
    if (!file.exists()) {
        System.err.println(""+imgPath+"   該文件不存在!");
        return;
    }
    Image src = ImageIO.read(new File(imgPath));
    int width = src.getWidth(null);
    int height = src.getHeight(null);
    if (needCompress) { // 壓縮LOGO
        if (width > WIDTH) {
            width = WIDTH;
        }
        if (height > HEIGHT) {
            height = HEIGHT;
        }
        Image image = src.getScaledInstance(width, height,
                Image.SCALE_SMOOTH);
        BufferedImage tag = new BufferedImage(width, height,
                BufferedImage.TYPE_INT_RGB);
        Graphics g = tag.getGraphics();
        g.drawImage(image, 0, 0, null); // 繪製縮小後的圖
        g.dispose();
        src = image;
    }
    // 插入LOGO
    Graphics2D graph = source.createGraphics();
    int x = (QRCODE_SIZE - width) / 2;
    int y = (QRCODE_SIZE - height) / 2;
    graph.drawImage(src, x, y, width, height, null);
    Shape shape = new RoundRectangle2D.Float(x, y, width, width, 6, 6);
    graph.setStroke(new BasicStroke(3f));
    graph.draw(shape);
    graph.dispose();
}

/**
 * 
 * @param content 二維碼內容
 * @param imgPath 讀取圖片路徑 放到二維碼中間
 * @param destPath 存放圖片路徑
 * @param needCompress 
 * @throws Exception
 */
public static void encode(String content, String imgPath, String destPath,
        boolean needCompress) throws Exception {
    BufferedImage image = QRCodeUtil.createImage(content, imgPath,
            needCompress);
    //mkdirs(destPath);
   // String file = new Random().nextInt(99999999)+".png";
    //String file = "qrcode.png";//生成二維碼的圖片
//    ImageIO.write(image, FORMAT_NAME, new File(destPath+"/"+file));
    ImageIO.write(image, FORMAT_NAME, new File(destPath));
}


public static void mkdirs(String destPath) {
    File file =new File(destPath);   
    //當文件夾不存在時,mkdirs會自動創建多層目錄,區別於mkdir.(mkdir如果父目錄不存在則會拋出異常)
    if (!file.exists() && !file.isDirectory()) {
        file.mkdirs();
    }
}


public static void encode(String content, String imgPath, String destPath)
        throws Exception {
    QRCodeUtil.encode(content, imgPath, destPath, false);
}


public static void encode(String content, String destPath,
        boolean needCompress) throws Exception {
    QRCodeUtil.encode(content, null, destPath, needCompress);
}


public static void encode(String content, String destPath) throws Exception {
    QRCodeUtil.encode(content, null, destPath, false);
}


public static void encode(String content, String imgPath,
        OutputStream output, boolean needCompress) throws Exception {
    BufferedImage image = QRCodeUtil.createImage(content, imgPath,
            needCompress);
    ImageIO.write(image, FORMAT_NAME, output);
}


public static void encode(String content, OutputStream output)
        throws Exception {
    QRCodeUtil.encode(content, null, output, false);
}


public static String decode(File file) throws Exception {
    BufferedImage image;
    image = ImageIO.read(file);
    if (image == null) {
        return null;
    }
    BufferedImageLuminanceSource source = new BufferedImageLuminanceSource(
            image);
    BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));
    Result result;
    Hashtable hints = new Hashtable();
    hints.put(DecodeHintType.CHARACTER_SET, CHARSET);
    result = new MultiFormatReader().decode(bitmap, hints);
    String resultStr = result.getText();
    return resultStr;
}


public static String decode(String path) throws Exception {
    return QRCodeUtil.decode(new File(path));
}


public static void main(String[] args) throws Exception {
    String text = "http://blog.csdn.net/tb176";
  //下面讀取和生產圖片路徑自己設置
 QRCodeUtil.encode(text, "C:\\Users\\****\\Desktop\\qrcode\\share-wx.png", "C:\\Users\\****\\Desktop\\qrcode\\qrcode.png", true);
}

}

輔助類如下:

  

import java.awt.Graphics2D;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;

import com.google.zxing.LuminanceSource;
/**
 * 
 * @author ****
 *
 */
public class BufferedImageLuminanceSource extends LuminanceSource {
    private final BufferedImage image;
    private final int left;
    private final int top;

    public BufferedImageLuminanceSource(BufferedImage image) {
        this(image, 0, 0, image.getWidth(), image.getHeight());
    }

    public BufferedImageLuminanceSource(BufferedImage image, int left,
            int top, int width, int height) {
        super(width, height);

        int sourceWidth = image.getWidth();
        int sourceHeight = image.getHeight();
        if (left + width > sourceWidth || top + height > sourceHeight) {
            throw new IllegalArgumentException(
                    "Crop rectangle does not fit within image data.");
        }

        for (int y = top; y < top + height; y++) {
            for (int x = left; x < left + width; x++) {
                if ((image.getRGB(x, y) & 0xFF000000) == 0) {
                    image.setRGB(x, y, 0xFFFFFFFF); // = white
                }
            }
        }

        this.image = new BufferedImage(sourceWidth, sourceHeight,
                BufferedImage.TYPE_BYTE_GRAY);
        this.image.getGraphics().drawImage(image, 0, 0, null);
        this.left = left;
        this.top = top;
    }

   
    public byte[] getRow(int y, byte[] row) {
        if (y < 0 || y >= getHeight()) {
            throw new IllegalArgumentException(
                    "Requested row is outside the image: " + y);
        }
        int width = getWidth();
        if (row == null || row.length < width) {
            row = new byte[width];
        }
        image.getRaster().getDataElements(left, top + y, width, 1, row);
        return row;
    }

   
    public byte[] getMatrix() {
        int width = getWidth();
        int height = getHeight();
        int area = width * height;
        byte[] matrix = new byte[area];
        image.getRaster().getDataElements(left, top, width, height, matrix);
        return matrix;
    }

   
    public boolean isCropSupported() {
        return true;
    }

   
    public LuminanceSource crop(int left, int top, int width, int height) {
        return new BufferedImageLuminanceSource(image, this.left + left,
                this.top + top, width, height);
    }

   
    public boolean isRotateSupported() {
        return true;
    }

   
    public LuminanceSource rotateCounterClockwise() {
        int sourceWidth = image.getWidth();
        int sourceHeight = image.getHeight();
        AffineTransform transform = new AffineTransform(0.0, -1.0, 1.0,
                0.0, 0.0, sourceWidth);
        BufferedImage rotatedImage = new BufferedImage(sourceHeight,
                sourceWidth, BufferedImage.TYPE_BYTE_GRAY);
        Graphics2D g = rotatedImage.createGraphics();
        g.drawImage(image, transform, null);
        g.dispose();
        int width = getWidth();
        return new BufferedImageLuminanceSource(rotatedImage, top,
                sourceWidth - (left + width), getHeight(), width);
    }
}

以上是簡單java實現二維碼的生產,你可以通過掃描來查看是不是你想要的,下面來看下前段js怎麼生成二維碼的,這裏我把工具改爲WebStorm這樣我們不需要每次都啓動tomcat服了,它直接集成了這些功能,方便一些純前端開發。最好參考《點擊打開鏈接》因爲這裏說的太簡單明瞭了。

接下來是關於文本內容過長導致二維碼識別度降低的問題,我們這是會選擇吧長鏈接轉爲短鏈接,具體可以參考《點擊打開鏈接》下面是個人的測試案例

	public static String Long2short(String url) throws IOException{
			
			//生成短連接
			String reqUrl = "http://980.so/api.php?url="+ URLEncoder.encode(url,"UTF-8");
			logger.info("------轉換之前的reqUrl="+reqUrl);
			Map<String,String> map = new HashMap<String,String>();
			String tinyUrl = GetRequest.getRequest(reqUrl,map);//http請求
			if(tinyUrl != null && tinyUrl.startsWith("http://980.so/"))
			{
				url = tinyUrl;
			}
			logger.info("------轉換之後的url="+url);
			return url;
	}

主函數也貼出來吧

public static void main(String[] args) throws IOException {
		String url = "https://www.baidu.com/s?ie=utf-8&f=3&rsv_bp=1&tn=monline_dg&wd=980.so&oq=js%E7%94%9F%E6%88%90%E4%BA%8C%E7%BB%B4%E7%A0%81&rsv_pq=9f72e3720004d0d6&rsv_t=4723nWbFLUDh%2BxsJxCGBAJ%2BIyt%2F3OrwBNiGnGzQOpohNKYSqP9%2FbfPxFd9RIHq9s6A&rqlang=cn&rsv_enter=1&inputT=7382&rsv_sug3=15&rsv_sug1=15&rsv_sug7=100&bs=js%E7%94%9F%E6%88%90%E4%BA%8C%E7%BB%B4%E7%A0%81";
		Long2short(url);
	}


運行後,我們可以看到控制檯結果

------轉換之前的reqUrl=http://980.so/api.php?url=https%3A%2F%2Fwww.baidu.com%2Fs%3Fie%3Dutf-8%26f%3D3%26rsv_bp%3D1%26tn%3Dmonline_dg%26wd%3D980.so%26oq%3Djs%25E7%2594%259F%25E6%2588%2590%25E4%25BA%258C%25E7%25BB%25B4%25E7%25A0%2581%26rsv_pq%3D9f72e3720004d0d6%26rsv_t%3D4723nWbFLUDh%252BxsJxCGBAJ%252BIyt%252F3OrwBNiGnGzQOpohNKYSqP9%252FbfPxFd9RIHq9s6A%26rqlang%3Dcn%26rsv_enter%3D1%26inputT%3D7382%26rsv_sug3%3D15%26rsv_sug1%3D15%26rsv_sug7%3D100%26bs%3Djs%25E7%2594%259F%25E6%2588%2590%25E4%25BA%258C%25E7%25BB%25B4%25E7%25A0%2581
------轉換之後的url=http://980.so/31pVn4
從結果,我們可以看出效果。這時候你可以吧轉換之後的url複製到瀏覽器地址欄看看效果了,是不是一樣的咯~

今天到此了,後續……






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