java生成二维码工具类，亲测有效，转载请标明出处，谢谢！

工具类使用需要在项目中引入二维码处理所需要的jar包

1.pom.xml首先加入

<!-- https://mvnrepository.com/artifact/com.google.zxing/core -->
<dependency>
<groupId>com.google.zxing</groupId>
<artifactId>core</artifactId>
<version>3.3.0</version>
</dependency>
<!-- https://mvnrepository.com/artifact/com.google.zxing/javase -->
<dependency>
<groupId>com.google.zxing</groupId>
<artifactId>javase</artifactId>
<version>3.3.0</version>
</dependency>

当然，因为是直接从google上拿过来的jar有点臃肿，有兴趣的同学可以在官网的zxing项目下载完整代码研究，也可以直接把项目中的代码拿出来再编码处理，地址就在这里https://github.com/zxing/zxing/releases，时间宝贵，还是接着往下看吧！

2.引入jar 包后直接 maven update，然后复制下面代码到项目中就可以使用了，生成二维码encode，识别图中二维码decode。

package com.zhha.common.Util;

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 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.client.j2se.BufferedImageLuminanceSource;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.common.HybridBinarizer;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;

/**
* 二维码处理工具类
* @author duzhj
* @date 2019.1.17
*/
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;

/**
* 生成二维码的方法
*
* @param content 目标URL
* @param imgPath LOGO图片地址
* @param needCompress 是否压缩LOGO
* @return 二维码图片
* @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();
}

/**
* 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 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));
}

/**
* 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 imgPath LOGO地址
* @param destPath 存储地址
* @throws Exception
*/
public static void encode(String content, String imgPath, String destPath)
throws Exception {
QRCodeUtil.encode(content, imgPath, 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 void encode(String content, String destPath,
boolean needCompress) throws Exception {
QRCodeUtil.encode(content, null, destPath, needCompress);
}

/**
* 生成二维码
*
* @param content 内容
* @param destPath 存储地址
* @throws Exception
*/
public static void encode(String content, String destPath) throws Exception {
QRCodeUtil.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 = QRCodeUtil.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 {
QRCodeUtil.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 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 二维码图片地址
* @return 不是二维码的内容返回null,是二维码直接返回识别的结果
* @throws Exception
*/
public static String decode(String path) throws Exception {
return QRCodeUtil.decode(new File(path));
}

}

3.写在最后，导入的时候有个小坑，我不希望你直接复制进去就用，但相信你能克服困难，嘿嘿！！！