【转载自】一步一步教你用 java 生成二维码
一、下载所需jar包并导包
http://central.maven.org/maven2/com/google/zxing/core/
点击3.3.0
点击core - 3.3.0.jar
二、关键代码 BufferedImageLuminanceSource.java
package com.qx.cn.tool;
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);
}
}
三、公共工具类 QRCodeUtil.java
package com.qx.cn.tool;
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;
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 == null || "".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(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();
}
public static String 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));
return file;
}
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 String encode(String content, String imgPath, String destPath) throws Exception {
return QRCodeUtil.encode(content, imgPath, destPath, false);
}
public static String encode(String content, String destPath, boolean needCompress) throws Exception {
return QRCodeUtil.encode(content, null, destPath, needCompress);
}
public static String encode(String content, String destPath) throws Exception {
return QRCodeUtil.encode(content, null, 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, null, output, false);
}
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;
}
public static String decode(String path) throws Exception {
return QRCodeUtil.decode(new File(path));
}
}
四、工具类调用
1、二维码中间没有图像
String text = "http://www.dans88.com.cn";
QRCodeUtil.encode(text,"","d:/MyWorkDoc",true);
2、二维码中间带有图像
String text = "http://www.dans88.com.cn";
QRCodeUtil.encode(text, "d:/MyWorkDoc/my180.jpg", "d:/MyWorkDoc", true);