优质文章，及时送达

作者：红颜祸水nvn

来源：

步骤1

第一步首先创建一个普通的 Maven 项目，然后要实现二维码功能，我们肯定要使用别人提供好的 Jar 包，这里我用的是 google 提供的 jar，pom.xml 文件配置如下：

 <?xml version="1.0" encoding="UTF-8"?> 
<project xmlns="" 
xmlns:xsi="" 
xsi:schemaLocation=" "> 
<modelVersion>4.0.0</modelVersion> 
 
<groupId>org.javaboy</groupId> 
<artifactId>QRCode</artifactId> 
<version>1.0-SNAPSHOT</version> 
 
 
<dependencies> 
<!-- 添加 google 提供的二维码依赖 --> 
<dependency> 
<groupId>com.google.zxing</groupId> 
<artifactId>core</artifactId> 
<version>3.3.0</version> 
</dependency> 
</dependencies> 
 
</ project >  

步骤2

然后使用 google 提供的工具类，在项目根目录下创建一个 util 包，将所需要的工具类放进去。

工具类1 (BufferedImageLuminanceSource)

不废话，直接上代码

 /** 
* @author bai <br/> 
* @date 2020/7/1 9:27<br/> 
*/ 
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, ); 
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 == || 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, ); 
g.dispose; 
int width = getWidth; 
return new BufferedImageLuminanceSource(rotatedImage, top, sourceWidth - (left + width), getHeight, width); 
} 
 
}  

工具类2 (QRCodeUtil)

这里面可以修改一些参数，例如二维码的尺寸，宽高等等。

 /** 
* @author bai <br/> 
* @date 2020/7/1 9:29<br/> 
*/ 
public class  QRCodeUtil { 
private static final String CHARSET = "utf-8"; 
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; 
 
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 == || "".equals(imgPath)) { 
return image; 
} 
// 插入图片 
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 + " 该文件不存在！"); 
return; 
} 
Image src = ImageIO.read(new File(imgPath)); 
int width = src.getWidth; 
int height = src.getHeight; 
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, ); // 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, ); 
Shape shape = new RoundRectangle2D.Float(x, y, width, width, 6, 6); 
graph.setStroke(new BasicStroke(3f)); 
graph.draw(shape); 
graph.dispose; 
} 
 
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)); 
} 
 
public static BufferedImage encode(String content, String imgPath, boolean needCompress) throws Exception { 
BufferedImage image = QRCodeUtil.createImage(content, imgPath, needCompress); 
return image; 
} 
 
 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) throws Exception { 
QRCodeUtil.encode(content, imgPath, destPath,  false ); 
} 
// 被注释的方法 
/* 
* public static void encode(String content, String destPath, boolean 
* needCompress) throws Exception { QRCodeUtil.encode(content, , destPath, 
* needCompress); } 
*/ 
 
public static void encode(String content, String destPath) throws Exception { 
QRCodeUtil.encode(content, , 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, , output, false); 
} 
 
public static String decode(File file) throws Exception { 
BufferedImage image; 
image = ImageIO.read(file); 
if (image == ) { 
return ; 
} 
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)); 
} 
 
}  

启动类

这一步就是调用方法，一般大家使用这种功能都是为了实现业务，例如常见的扫描二维码跳转链接（页面），扫描二维码出现文字等等。有些二维码中间还带有 Logo 这种图片，将需要嵌入二维码的图片路径准备好就没有问题。

 /** 
* @author bai <br/> 
* @date 2020/7/1 9:31<br/> 
*/ 
public class QRCodeApplication { 
public static void main(String[] args) throws Exception { 
// 存放在二维码中的内容 
// 二维码中的内容可以是文字，可以是链接等 
String text = ""; 
// 嵌入二维码的图片路径 
//String imgPath = "C:\\Users\\Administrator\\Pictures\\img\\dog.jpg"; 
// 生成的二维码的路径及名称 
String destPath = "C:\\Users\\bai\\Pictures\\img\\code" + System.currentTimeMillis + ".jpg"; 
//生成二维码 
QRCodeUtil.encode(text, , 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); 
} 
}  

效果截图

源码奉上

码云：

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