java生成二維碼和解析內容

一. 背景：

小熙最近項目常用到二維碼，但都是前端生成的，所以小熙想是否後端可以替代下。於是小熙特意查找學些相關資料，分享下學習結果。

二. 引入依賴和工具類

谷歌提供的依賴座標（可去中央倉庫搜索適合自己的版本，搜索：ZXing Core）

       <!--谷歌二維碼提供依賴-->
        <dependency>
            <groupId>com.google.zxing</groupId>
            <artifactId>core</artifactId>
            <version>3.4.0</version>
        </dependency>

谷歌原始提供工具類

package com.chengxi.datalom.utils.qRCode;
 
import java.awt.Graphics2D;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import com.google.zxing.LuminanceSource;
 
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;
	}

	@Override
	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;
	}

	@Override
	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;
	}

	@Override
	public boolean isCropSupported() {
		return true;
	}

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

	@Override
	public boolean isRotateSupported() {
		return true;
	}

	@Override
	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);
	}
 
}

封裝工具類（直接使用，可根據自己的喜好，修改內部的長寬等非必要參數）

package com.chengxi.datalom.utils.qRCode;
 
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 chengxi
 */
public class QRCodeUtil {
	private static final String CHARSET = "utf-8";
	private static final String FORMAT_NAME = "JPG";
	// 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;

	/**
	 * 創建圖片
	 * @param content
	 * @param imgPath
	 * @param needCompress
	 * @return
	 * @throws Exception
	 */
	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;
	}

	/**
	 * 插入圖片
	 * @param source
	 * @param imgPath
	 * @param needCompress
	 * @throws Exception
	 */
	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();
	}

	/**
	 * 編碼
	 * @param content
	 * @param imgPath
	 * @param destPath
	 * @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)+".jpg";
		// ImageIO.write(image, FORMAT_NAME, new File(destPath+"/"+file));
		ImageIO.write(image, FORMAT_NAME, new File(destPath));
	}

	/**
	 * 編碼
	 * @param content
	 * @param imgPath
	 * @param needCompress
	 * @return
	 * @throws Exception
	 */
	public static BufferedImage encode(String content, String imgPath, boolean needCompress) throws Exception {
		BufferedImage image = QRCodeUtil.createImage(content, imgPath, needCompress);
		return image;
	}

	/**
	 * 創建文件夾
	 * @param 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();
		}
	}

	/**
	 * 編碼
	 * @param content
	 * @param imgPath
	 * @param destPath
	 * @throws Exception
	 */
	public static void encode(String content, String imgPath, String destPath) throws Exception {
		QRCodeUtil.encode(content, imgPath, destPath, false);
	}
	// 被註釋的方法
	/*
	 * public static void encode(String content, String destPath, boolean
	 * needCompress) throws Exception { QRCodeUtil.encode(content, null, destPath,
	 * needCompress); }
	 */

	/**
	 * 編碼
	 * @param content
	 * @param destPath
	 * @throws Exception
	 */
	public static void encode(String content, String destPath) throws Exception {
		QRCodeUtil.encode(content, null, destPath, false);
	}

	/**
	 * 編碼
	 * @param content
	 * @param imgPath
	 * @param output
	 * @param needCompress
	 * @throws Exception
	 */
	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);
	}

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

	/**
	 * 解碼
	 * @param file
	 * @return
	 * @throws Exception
	 */
	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;
	}

	/**
	 * 解碼
	 * @param path
	 * @return
	 * @throws Exception
	 */
	public static String decode(String path) throws Exception {
		return QRCodeUtil.decode(new File(path));
	}
 
}

三. 代碼演示

演示文字輸出

（1）代碼：

 	    // 添加內容
        String content = "小熙生成的二維碼";
        // 嵌入圖片路徑
        String imgPath = "G:\\IDEAWorkSapse\\Test\\data-lom\\src\\main\\resources\\img\\007.jpg";
        // 生成二維碼路徑
        String destPath = "G:\\IDEAWorkSapse\\Test\\data-lom\\src\\main\\resources\\img\\001img.jpg";
        // 生成二維碼
        QRCodeUtil.encode(content,imgPath,destPath,true);
        // 解析二維碼
        String decode = QRCodeUtil.decode(destPath);
        // 打印解析內容
        System.out.println("decode: "+decode);

（2）插入的圖片

（3）結果

生成的二維碼（掃碼可打印出輸入的文字）：

解析打印結果：

掃碼跳轉網址（只需要把內容替換成網址即可）
小熙附上生成後二維碼：

四. base64傳輸工具（前後端分離推薦使用）

代碼：

package com.chengxi.datalom.utils;

import org.apache.commons.lang3.StringUtils;
import org.springframework.util.Base64Utils;
 
import java.io.*;

/**
 * 圖片 與 Base64 互相轉換
 * @author chengxi
 */
public class Base64Util {


    public static void main(String[] args) {
        String imgBase64Str = Base64Util.ImageToBase64ByLocal("G:\\IDEAWorkSapse\\Test\\data-lom\\src\\main\\resources\\img\\002img.jpg");
        System.out.println(imgBase64Str);

        boolean b = Base64Util.Base64ToImage(imgBase64Str,"G:\\IDEAWorkSapse\\Test\\data-lom\\src\\main\\resources\\img\\test.jpg");
        System.out.println(b);
    }

 
    /**
     * 本地圖片轉換成base64字符串
     * @param imgFile	本地圖片全路徑 （注意：帶文件名）
     *  (將圖片文件轉化爲字節數組字符串，並對其進行Base64編碼處理)
     * @return
     */
    public static String ImageToBase64ByLocal(String imgFile) {
        byte[] data = null;
 
        // 讀取圖片字節數組
        try {
            InputStream in = new FileInputStream(imgFile);
 
            data = new byte[in.available()];
            in.read(data);
            in.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
 
       // 返回Base64編碼過的字節數組字符串
        return Base64Utils.encodeToString(data);
    }
 
 
 
 
    /**
     * base64字符串轉換成圖片 (對字節數組字符串進行Base64解碼並生成圖片)
     * @param imgStr		base64字符串
     * @param imgFilePath	解析生成圖片的存放路徑  （注意：帶文件名）
     * @return
     */
    public static boolean Base64ToImage(String imgStr,String imgFilePath) {
        // 圖像數據爲空
        if (StringUtils.isEmpty(imgStr)) {
            return false;
        }

        try {
            // Base64解碼
            byte[] b = Base64Utils.decodeFromString(imgStr);
            for (int i = 0; i < b.length; ++i) {
                // 調整異常數據
                if (b[i] < 0) {
                    b[i] += 256;
                }
            }
 
            OutputStream out = new FileOutputStream(imgFilePath);
            out.write(b);
            out.flush();
            out.close();
 
            return true;
        } catch (Exception e) {
            return false;
        }
    }

}

如果是後端生成二維碼，使用base64傳輸給前端或接收還是很方便的。
掃描上方二維碼不迷路喲。

java生成二維碼和解析內容

一. 背景：

二. 引入依賴和工具類

三. 代碼演示

四. base64傳輸工具（前後端分離推薦使用）

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