Java 后台实现二维码生成（生成 base64或者直接本地保存
生成 base64的二维码，前台展示
引入 jar 包
<!-- 条形码、二维码生成 -->
<dependency>
<groupId>com.google.zxing</groupId>
<artifactId>core</artifactId>
<version>2.2</version>
</dependency>
<dependency>
<groupId>com.google.zxing</groupId>
<artifactId>javase</artifactId>
<version>2.2</version>
</dependency>
编写工具类
QrCodeUtils.java：
public class QrCodeUtils {
public static String creatRrCode(String contents, int width, int height) {
String binary = null;
Hashtable hints = new Hashtable();
hints.put(EncodeHintType.CHARACTER_SET, "utf-8");
try {
BitMatrix bitMatrix = new MultiFormatWriter().encode(
contents, BarcodeFormat.QR_CODE, width, height, hints);
// 1、读取文件转换为字节数组
ByteArrayOutputStream out = new ByteArrayOutputStream();
BufferedImage image = toBufferedImage(bitMatrix);
//转换成png格式的IO流
ImageIO.write(image, "png", out);
byte[] bytes = out.toByteArray();
// 2、将字节数组转为二进制
BASE64Encoder encoder = new BASE64Encoder();
binary = encoder.encodeBuffer(bytes).trim();
} catch (WriterException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return binary;
}
/**
* image流数据处理
*
* @author ianly
*/
public static BufferedImage toBufferedImage(BitMatrix matrix) {
int width = matrix.getWidth();
int height = matrix.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, matrix.get(x, y) ? 0xFF000000 : 0xFFFFFFFF);
}
}
return image;
}
public static void main(String[] args) {
String binary = QrCodeUtils.creatRrCode("https://blog.csdn.net/ianly123", 200,200);
System.out.println(binary);
}
}
controller层获取生成图片二进制代码：
String binary = QrCodeUtils.creatRrCode("二维码内容", 200,200);
前台展示
<div id="qrcode"><img src="data:image/png;base64,${binary }"></div>
后台生成二维码图片（可以内嵌 logo）文件，保存到本地。
生成二维码(内嵌LOGO)
package xin.ianly.utils.qrcode;
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.OutputStream;
import java.util.Hashtable;
import java.util.Random;
/**
* @author ianly
* @description
* @date 2018-05-31
*/
public class QrCodeUtils2 {
private static final String CHARSET = "utf-8";
private static final String FORMAT = "JPG";
// 二维码尺寸
private static final int QRCODE_SIZE = 300;
// LOGO宽度
private static final int LOGO_WIDTH = 60;
// LOGO高度
private static final int LOGO_HEIGHT = 60;
private static BufferedImage createImage(String content, String logoPath, boolean needCompress) throws Exception {
Hashtable<EncodeHintType, Object> hints = new Hashtable<EncodeHintType, Object>();
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 (logoPath == null || "".equals(logoPath)) {
return image;
}
// 插入图片
QrCodeUtils2.insertImage(image, logoPath, needCompress);
return image;
}
/**
* 插入LOGO
*
* @param source
* 二维码图片
* @param logoPath
* LOGO图片地址
* @param needCompress
* 是否压缩
* @throws Exception
*/
private static void insertImage(BufferedImage source, String logoPath, boolean needCompress) throws Exception {
File file = new File(logoPath);
if (!file.exists()) {
throw new Exception("logo file not found.");
}
Image src = ImageIO.read(new File(logoPath));
int width = src.getWidth(null);
int height = src.getHeight(null);
if (needCompress) { // 压缩LOGO
if (width > LOGO_WIDTH) {
width = LOGO_WIDTH;
}
if (height > LOGO_HEIGHT) {
height = LOGO_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();
}
/**
* 生成二维码(内嵌LOGO)
* 二维码文件名随机，文件名可能会有重复
*
* @param content
* 内容
* @param logoPath
* 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 logoPath, String destPath, boolean needCompress) throws Exception {
BufferedImage image = QrCodeUtils2.createImage(content, logoPath, needCompress);
mkdirs(destPath);
String fileName = new Random().nextInt(99999999) + "." + FORMAT.toLowerCase();
ImageIO.write(image, FORMAT, new File(destPath + "/" + fileName));
return fileName;
}
/**
* 生成二维码(内嵌LOGO)
* 调用者指定二维码文件名
*
* @param content
* 内容
* @param logoPath
* LOGO地址
* @param destPath
* 存放目录
* @param fileName
* 二维码文件名
* @param needCompress
* 是否压缩LOGO
* @throws Exception
*/
public static String encode(String content, String logoPath, String destPath, String fileName, boolean needCompress) throws Exception {
BufferedImage image = QrCodeUtils2.createImage(content, logoPath, needCompress);
mkdirs(destPath);
fileName = fileName.substring(0, fileName.indexOf(".")>0?fileName.indexOf("."):fileName.length())
+ "." + FORMAT.toLowerCase();
ImageIO.write(image, FORMAT, new File(destPath + "/" + fileName));
return fileName;
}
/**
* 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)
* @param destPath
* 存放目录
*/
public static void mkdirs(String destPath) {
File file = new File(destPath);
if (!file.exists() && !file.isDirectory()) {
file.mkdirs();
}
}
/**
* 生成二维码(内嵌LOGO)
*
* @param content
* 内容
* @param logoPath
* LOGO地址
* @param destPath
* 存储地址
* @throws Exception
*/
public static String encode(String content, String logoPath, String destPath) throws Exception {
return QrCodeUtils2.encode(content, logoPath, destPath, false);
}
/**
* 生成二维码
*
* @param content
* 内容
* @param destPath
* 存储地址
* @param needCompress
* 是否压缩LOGO
* @throws Exception
*/
public static String encode(String content, String destPath, boolean needCompress) throws Exception {
return QrCodeUtils2.encode(content, null, destPath, needCompress);
}
/**
* 生成二维码
*
* @param content
* 内容
* @param destPath
* 存储地址
* @throws Exception
*/
public static String encode(String content, String destPath) throws Exception {
return QrCodeUtils2.encode(content, null, destPath, false);
}
/**
* 生成二维码(内嵌LOGO)
*
* @param content
* 内容
* @param logoPath
* LOGO地址
* @param output
* 输出流
* @param needCompress
* 是否压缩LOGO
* @throws Exception
*/
public static void encode(String content, String logoPath, OutputStream output, boolean needCompress)
throws Exception {
BufferedImage image = QrCodeUtils2.createImage(content, logoPath, needCompress);
ImageIO.write(image, FORMAT, 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 {
QrCodeUtils2.encode(content, null, output, false);
}
/**
* 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 QrCodeUtils2.decode(new File(path));
}
public static void main(String[] args) throws Exception {
String text = "https://blog.csdn.net/ianly123";
//不含Logo
//QrCodeUtils2.encode(text, null, "/Users/ianly/Documents/picture", true);
//含Logo，不指定二维码图片名
//QrCodeUtils2.encode(text, "/Users/ianly/Documents/picture/google-icon.jpg", "/Users/ianly/Documents/picture/", true);
//含Logo，指定二维码图片名
QrCodeUtils2.encode(text, "/Users/ianly/Documents/picture/google-icon.jpg", "/Users/ianly/Documents/picture", "qrcode", true);
}
}
