用JAVA 设计生成二维码详细教程

教你一步一步用 java 设计生成二维码

在物联网的时代，二维码是个很重要的东西了，现在无论什么东西都要搞个二维码标志，唯恐落伍，就差人没有用二维码识别了。也许有一天生分证或者户口本都会用二维码识别了。今天心血来潮，看见别人都为自己的博客添加了二维码，我也想搞一个测试一下.

主要用来实现两点：

1. 生成任意文字的二维码.

2. 在二维码的中间加入图像.

一、准备工作。

准备QR二维码3.0 版本的core包和一张jpg图片。

下载QR二维码包。

首先得下载 zxing.jar 包, 我这里用的是3.0 版本的core包

下载地址: 现在已经迁移到了github: https://github.com/zxing/zxing/wiki/Getting-Started-Developing,

当然你也可以从maven仓库下载jar 包: http://central.maven.org/maven2/com/google/zxing/core/

二、程序设计

 1、启动eclipse，新建一个java项目，命好项目名（本例取名为QRCodeSoft）。点下一步：

2、导入zxing.jar 包, 我这里用的是3.0 版本的core包：点“添加外部JAR(X)…”。

3、新建两个类，分别是：

BufferedImageLuminanceSource.java

QRCodeUtil.java

关键代码在于：BufferedImageLuminanceSource.java 和QRCodeUtil.java , 其中测试的main 方法位于 QRCodeUtil.java 中。

BufferedImageLuminanceSource.java程序代码：

package com.yihaomen.barcode;

import java.awt.Graphics2D;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;

import com.google.zxing.LuminanceSource;

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;
}

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;
}

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;
}

public boolean isCropSupported() {
return true;
}

public LuminanceSource crop(int left, int top, int width, int height) {
return new BufferedImageLuminanceSource(image, this.left + left,
this.top + top, width, height);
}

public boolean isRotateSupported() {
return true;
}

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);
}
}

QRCodeUtil.java的程序代码：

package com.yihaomen.barcode;

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

/**
* 二维码工具类
*
*/
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<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 (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)
* @author lanyuan
* Email: mmm333zzz520@163.com
* @date 2013-12-11 上午10:16:36
* @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();
}
}

/**
* 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<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 QRCodeUtil.decode(new File(path));
}

public static void main(String[] args) throws Exception {
String text = "http://www.yihaomen.com";
QRCodeUtil.encode(text, "c:/me.jpg", "c:/barcode", true);
}
}

生成不带logo 的二维码

程序代码如下：

public static void main(String[] args) throws Exception {
 String text = "http://www.dans88.com.cn";
 QRCodeUtil.encode(text,"","d:/MyWorkDoc",true);
}

运行这个测试方法，生成的二维码不带 logo , 样式如下:

有兴趣可以用手机扫描一下

生成带logo 的二维码

logo 可以用自己的头像，或者自己喜欢的一个图片都可以 , 采用如下代码，程序代码如下：

public static void main(String[] args) throws Exception {
 String text = "http://www.dans88.com.cn";
 QRCodeUtil.encode(text, "d:/MyWorkDoc/my180.jpg", "d:/MyWorkDoc", true);
}

唯一的区别是，在前面的基础上指定了logo 的地址，这里测试都用了c盘的图片文件

用手机扫描，能出现要出现的文字，点击就进入自己的网站。