1 Introduction
This tool class uses google open source project zxing as a java project to generate and parse QR code. The code has been commented. As for the principle of QR code and zxing's Api, please Baidu.
2. Code implementation
To use zxing, you need to import the jar package first, and maven dependencies are used here.
<dependency>
<groupId>com.google.zxing</groupId>
<artifactId>core</artifactId>
<version>3.3.0</version>
</dependency>package com.dmeo.utils;
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.io.UnsupportedEncodingException;
import java.net.URL;
import java.net.URLDecoder;
import java.util.Hashtable;
import java.util.Random;
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;
/**
*
*@description:使用谷歌开源项目zxing生成和解析二维码
*2018年4月11日 下午2:29:41
*/
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;
/*********************二维码的生成方法以及重载*********************/
/**
* 生成二维码(内嵌LOGO)
*
* @param content
* 内容
* @param imgPath
* LOGO地址
* @param destPath
* 存放目录
* @param needCompress
* 是否压缩LOGO
* @throws Exception
*/
public static String encode(String content, String imgPath, String destPath,
boolean needCompress) throws Exception {
BufferedImage image = createImage(content, imgPath,
needCompress);
mkdirs(destPath);
String file = new Random().nextInt(99999999)+".jpg";
ImageIO.write(image, FORMAT_NAME, new File(destPath+"/"+file));
return file;
}
/**
* 生成二维码(内嵌LOGO)
*
* @param content
* 内容
* @param imgPath
* LOGO地址
* @param destPath
* 存储地址
* @throws Exception
*/
public static String encode(String content, String imgPath, String destPath)
throws Exception {
String fileName = encode(content, imgPath, destPath, true);
return fileName;
}
/**
* 生成二维码(不包含LOGO)
*
* @param content
* 内容
* @param destPath
* 存储地址
* @param needCompress
* 是否压缩
* @throws Exception
*/
public static void encode(String content, String destPath,
boolean needCompress) throws Exception {
encode(content, null, destPath, needCompress);
}
/**
* 生成二维码(不包含LOGO,且不压缩图片)
*
* @param content
* 内容
* @param destPath
* 存储地址
* @throws Exception
*/
public static void encode(String content, String destPath) throws Exception {
encode(content, null, destPath, false);
}
/**
* 生成二维码(内嵌LOGO)
*
* @param content
* 内容
* @param imgPath
* LOGO地址
* @param output
* 输出流
* @param needCompress
* 是否压缩LOGO
* @throws Exception
*/
public static void encode(String content, String imgPath,
OutputStream output, boolean needCompress) throws Exception {
BufferedImage image = createImage(content, imgPath,
needCompress);
ImageIO.write(image, FORMAT_NAME, output);
}
/**
* 生成二维码
*
* @param content
* 内容
* @param output
* 输出流
* @throws Exception
*/
public static void encode(String content, OutputStream output)
throws Exception {
encode(content, null, output, false);
}
/*********************二维码的解析方法以及重载*********************/
/**
* 解析二维码
*
* @param file
* 二维码图片
* @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<DecodeHintType, Object> hints = new Hashtable<DecodeHintType, Object>();
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
* 二维码图片地址
* @return
* @throws Exception
*/
public static String decode(String path) throws Exception {
return decode(new File(path));
}
/************************在使用ecode方法创建二维码时调用的静态方法**********************/
private static BufferedImage createImage(String content, String imgPath,
boolean needCompress) throws Exception {
Hashtable<EncodeHintType, Object> hints = new Hashtable<EncodeHintType, Object>();
// 设置QR二维码的纠错级别（H为最高级别）具体级别信息
hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
// 内容所使用编码
hints.put(EncodeHintType.CHARACTER_SET, CHARSET);
// 设置图片的边距
hints.put(EncodeHintType.MARGIN, 1);
// 生成矩阵
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LOGO
insertImage(image, imgPath, needCompress);
return image;
}
/**
* 插入LOG图片到已经生成的二维码中
*
* @param source
* 二维码图片
* @param imgPath
* LOGO图片地址
* @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();
}
/**
* @param destPath 存放目录
*/
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();
}
}
}
Among them, java.awt.Graphics2D is needed to parse the graphic image when parsing the QR code image.
package com.dmeo.utils;
import java.awt.Graphics2D;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import com.google.zxing.LuminanceSource;
/**
*
* @description:该类主要为调用java.awt.Graphics2D中的类来解析图形图像
*
*/
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);
}
}
3. Conclusion.
This tool class is only for reference and learning the codes of other great gods on the Internet, and on this basis, you can learn by yourself. It is just a learning project and is not for commercial use. If there is any infringement or loss to the original author, please contact to delete it. Thank you.