Java实现二维码的生成与解析
Java实现二维码的生成
二维码 (dimensional barcode) ，又称二维条码，是在一维条码的基础上扩展出的一种具有可读性的条码。设备扫描二维条码，通过识别条码的长度和宽度中所记载的二进制数据，可获取其中所包含的信息。相比一维条码，二维码记载更复杂的数据，比如图片、网络链接等。
当然了，二维码是什么并不是我们今天研究的对象，你都进来看这篇文章了，肯定也知道什么是二维码啦~
入门案例
Google提供了XML生成的jar包，我们只需要导入其依赖使用即可， 站在巨人的肩膀上好乘凉~
<dependency>
<groupId>com.google.zxing</groupId>
<artifactId>core</artifactId>
<version>3.3.0</version>
</dependency>
<dependency>
<groupId>com.google.zxing</groupId>
<artifactId>javase</artifactId>
<version>3.3.0</version>
</dependency>
工具类代码
package cn.rayfoo.utils;
import com.google.zxing.*;
import com.google.zxing.client.j2se.BufferedImageLuminanceSource;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.common.HybridBinarizer;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.geom.RoundRectangle2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Hashtable;
/**
* @Author: rayfoo@qq.com
* @Date: 2020/7/13 5:20 下午
* @Description: 二维码工具类
*/
public class QRCodeUtil {
//编码
private static final String CHARSET = "utf-8";
//文件格式
private static final String FORMAT_NAME = "JPG";
// 二维码尺寸
private static final int QRCODE_SIZE = 300;
// LOGO宽度
private static final int WIDTH = 60;
// LOGO高度
private static final int HEIGHT = 60;
/**
* 生成二维码
* @param content 内容
* @param imgPath logo
* @param needCompress 是否需要压缩
* @return java.awt.image.BufferedImage
* @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;
}
// 插入图片
QRCodeUtil.insertImage(image, imgPath, needCompress);
return image;
}
/**
* 插入logo
* @param source 二维码图片
* @param imgPath logo路径
* @param needCompress 是否压缩
* @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 + " 该文件不存在！");
return;
}
Image src = ImageIO.read(new File(imgPath));
int width = src.getWidth(null);
int height = src.getHeight(null);
if (needCompress) { // 压缩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); // 绘制缩小后的图
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();
}
public static void mkdirs(String destPath) {
File file = new File(destPath);
// 当文件夹不存在时，mkdirs会自动创建多层目录，区别于mkdir．(mkdir如果父目录不存在则会抛出异常)
if (!file.exists() && !file.isDirectory()) {
file.mkdirs();
}
}
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));
}
/**
* 生成二维码，获得到输入流 log内嵌
* @param content 内容
* @param imgPath logo路径
* @param output 输入流
* @param needCompress 是否压缩
* @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);
}
/**
* 获取指定的logo文件输入流
* @param logoPath logo路径
* @return java.io.InputStream
*/
public static InputStream getResourceAsStream(String logoPath) {
return QRCodeUtil.class.getResourceAsStream(logoPath);
}
/**
* 将要解析的二维码的存放路径
* @param file 要解析的二维码
* @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;
}
/**
* 解析二维码
* @param path 要解析的二维码路径
* @return
* @throws Exception
*/
public static String decode(String path) throws Exception {
return QRCodeUtil.decode(new File(path));
}
}
测试类代码
package cn.rayfoo.utils.test;
import cn.rayfoo.utils.QRCodeUtil;
/**
* @Author: rayfoo@qq.com
* @Date: 2020/7/13 5:20 下午
* @Description:
*/
public class TestApp {
public static void main(String[] args) throws Exception {
// 存放在二维码中的内容
String text = "http://blog.vantee.cn";
// 嵌入二维码的图片路径
String imgPath = "/Users/rayfoo/Downloads/logo.jpg";
// 生成的二维码的路径及名称
String destPath = "/Users/rayfoo/Downloads/MyQRCode.png";
//生成二维码
QRCodeUtil.encode(text, imgPath, destPath, true);
// 解析二维码
String str = QRCodeUtil.decode(destPath);
// 打印出解析出的内容
System.out.println(str);
}
}
方法介绍：
QRCodeUtil.encode(text, imgPath, destPath, true);
方法说明：
使用encode方法生成二维码
- text：放入二维码中的内容
- imgPath：嵌入二维码的图片路径
- destPath：二维码的输出路径
- needCompress：是否压缩二维码
QRCodeUtil.decode(recode);
解析二维码：
- recode：二维码路径
参考文章：CSDN地址
