java生成二维码和解析内容以及传输
一. 背景：
小熙最近项目常用到二维码，但都是前端生成的，所以小熙想是否后端可以替代下。于是小熙特意查找些相关资料，分享下学习结果。
二. 引入依赖和工具类：
- 谷歌提供的依赖坐标（可去中央仓库搜索适合自己的版本，搜索：ZXing Core）
com.google.zxing
core
3.4.0
- 谷歌原始提供工具类
package com.chengxi.datalom.utils.qRCode;
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;
}
@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);
}
}
- 封装工具类（直接使用，可根据自己的喜好，修改内部的长宽等非必要参数）
package com.chengxi.datalom.utils.qRCode;
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 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;
/**
* @author chengxi
*/
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;
/**
* 创建图片
* @param content
* @param imgPath
* @param needCompress
* @return
* @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;
}
/**
* 插入图片
* @param source
* @param imgPath
* @param needCompress
* @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();
}
/**
* 编码
* @param content
* @param imgPath
* @param destPath
* @param needCompress
* @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));
ImageIO.write(image, FORMAT_NAME, new File(destPath));
}
/**
* 编码
* @param content
* @param imgPath
* @param needCompress
* @return
* @throws Exception
*/
public static BufferedImage encode(String content, String imgPath, boolean needCompress) throws Exception {
BufferedImage image = QRCodeUtil.createImage(content, imgPath, needCompress);
return image;
}
/**
* 创建文件夹
* @param destPath
*/
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();
}
}
/**
* 编码
* @param content
* @param imgPath
* @param destPath
* @throws Exception
*/
public static void encode(String content, String imgPath, String destPath) throws Exception {
QRCodeUtil.encode(content, imgPath, destPath, false);
}
// 被注释的方法
/*
* public static void encode(String content, String destPath, boolean
* needCompress) throws Exception { QRCodeUtil.encode(content, null, destPath,
* needCompress); }
*/
/**
* 编码
* @param content
* @param destPath
* @throws Exception
*/
public static void encode(String content, String destPath) throws Exception {
QRCodeUtil.encode(content, null, destPath, false);
}
/**
* 编码
* @param content
* @param imgPath
* @param output
* @param needCompress
* @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);
}
/**
* 编码
* @param content
* @param output
* @throws Exception
*/
public static void encode(String content, OutputStream output) throws Exception {
QRCodeUtil.encode(content, null, output, false);
}
/**
* 解码
* @param file
* @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;
}
/**
* 解码
* @param path
* @return
* @throws Exception
*/
public static String decode(String path) throws Exception {
return QRCodeUtil.decode(new File(path));
}
}
三. 代码演示：
-
演示文字输出
（1） 代码：
// 添加内容 String content = "小熙生成的二维码"; // 嵌入图片路径 String imgPath = "G:\\IDEAWorkSapse\\Test\\data-lom\\src\\main\\resources\\img\\007.jpg"; // 生成二维码路径 String destPath = "G:\\IDEAWorkSapse\\Test\\data-lom\\src\\main\\resources\\img\\001img.jpg"; // 生成二维码 QRCodeUtil.encode(content,imgPath,destPath,true); // 解析二维码 String decode = QRCodeUtil.decode(destPath); // 打印解析内容 System.out.println("decode: "+decode);（2）插入的图片
（3）结果生成的二维码（扫码可打印出输入的文字）：
解析打印结果：
-
扫码跳转网址（只需要把内容替换成网址即可）
小熙附上生成后二维码：
四. base64传输工具（前后端分离推荐使用）：
- 代码：
package com.chengxi.datalom.utils;
import org.apache.commons.lang3.StringUtils;
import org.springframework.util.Base64Utils;
import java.io.*;
/**
* 图片 与 Base64 互相转换
* @author chengxi
*/
public class Base64Util {
public static void main(String[] args) {
String imgBase64Str = Base64Util.ImageToBase64ByLocal("G:\\IDEAWorkSapse\\Test\\data-lom\\src\\main\\resources\\img\\002img.jpg");
System.out.println(imgBase64Str);
boolean b = Base64Util.Base64ToImage(imgBase64Str,"G:\\IDEAWorkSapse\\Test\\data-lom\\src\\main\\resources\\img\\test.jpg");
System.out.println(b);
}
/**
* 本地图片转换成base64字符串
* @param imgFile 本地图片全路径 （注意：带文件名）
* (将图片文件转化为字节数组字符串，并对其进行Base64编码处理)
* @return
*/
public static String ImageToBase64ByLocal(String imgFile) {
byte[] data = null;
// 读取图片字节数组
try {
InputStream in = new FileInputStream(imgFile);
data = new byte[in.available()];
in.read(data);
in.close();
} catch (IOException e) {
e.printStackTrace();
}
// 返回Base64编码过的字节数组字符串
return Base64Utils.encodeToString(data);
}
/**
* base64字符串转换成图片 (对字节数组字符串进行Base64解码并生成图片)
* @param imgStr base64字符串
* @param imgFilePath 解析生成图片的存放路径 （注意：带文件名）
* @return
*/
public static boolean Base64ToImage(String imgStr,String imgFilePath) {
// 图像数据为空
if (StringUtils.isEmpty(imgStr)) {
return false;
}
try {
// Base64解码
byte[] b = Base64Utils.decodeFromString(imgStr);
for (int i = 0; i < b.length; ++i) {
// 调整异常数据
if (b[i] < 0) {
b[i] += 256;
}
}
OutputStream out = new FileOutputStream(imgFilePath);
out.write(b);
out.flush();
out.close();
return true;
} catch (Exception e) {
return false;
}
}
}
如果是后端生成二维码，使用base64传输给前端或接收还是很方便的。
扫描上方二维码不迷路哟。