二维码分为好多种，我们最常用的是qrcode类型的二维码，以下有三种生成方式以及解析方式：
附所需jar包或者js地址
第一种：依赖qrcode.jar
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import java.awt.Color;
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import java.awt.Graphics2D;
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import java.awt.image.BufferedImage;
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import java.io.File;
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import java.io.UnsupportedEncodingException;
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import javax.imageio.ImageIO;
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import com.swetake.util.Qrcode;
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/**获取qrcode jar包 https://osdn.jp/projects/qrcode
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* 生成qrcode二维码
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* @author fangyi
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*
-
*/
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public
class CreateQrCode {
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public static void main(String[] args) throws Exception {
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Qrcode qrcode=
new Qrcode();
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qrcode.setQrcodeErrorCorrect(
'M');
//纠错等级
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qrcode.setQrcodeEncodeMode(
'B');
//N代表数字 A代表字母 B代表其他
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qrcode.setQrcodeVersion(
7);
//版本
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String qrData =
"www.baidu.com";
//二维码信息内容
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int width=
67+
12*(
7-
1);
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int height=
67+
12*(
7-
1);
-
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BufferedImage bufferedImage =
new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
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//画图工具
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Graphics2D gs= bufferedImage.createGraphics();
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//设置属性
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gs.setBackground(Color.WHITE);
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gs.setColor(Color.BLACK);
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gs.clearRect(
0,
0, width, height);
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//填充
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int pixoff=
2;
//偏移量
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byte[] d = qrData.getBytes(
"gb2312");
//编码防止有中文
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if (
0 < d.length && d.length<
120) {
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boolean[][] s = qrcode.calQrcode(d);
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for (
int i =
0; i < s.length; i++) {
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for (
int j =
0; j < s.length; j++) {
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if(s[j][i]){
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gs.fillRect(i*
3+pixoff, j*
3+pixoff,
3,
3);
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}
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}
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}
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}
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//关闭资源，并保存文件
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gs.dispose();
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bufferedImage.flush();
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ImageIO.write(bufferedImage,
"png",
new File(
"D:/qrcode.jpg"));
//输出到指定地方
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}
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}
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import java.awt.image.BufferedImage;
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import java.io.File;
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import java.io.IOException;
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import javax.imageio.ImageIO;
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import jp.sourceforge.qrcode.QRCodeDecoder;
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/**
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* 读取制定路径下的qrcode信息
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* @author fangyi
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*
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*/
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public
class ReaderQrcode {
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public static void main(String[] args) throws IOException {
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//指定的二维码文件路径
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File file=
new File(
"D:/jqueryqrcode.png");
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BufferedImage bufferedImage = ImageIO.read(file);
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QRCodeDecoder qrCodeDecoder =
new QRCodeDecoder();
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String result =
new String(qrCodeDecoder.decode(
new MyQRCodeImage(bufferedImage)),
"gb2312");
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//输出结果
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System.out.println(result);
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bufferedImage.flush();
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}
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}
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-
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import java.awt.image.BufferedImage;
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import jp.sourceforge.qrcode.data.QRCodeImage;
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/**
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* 自定义QRCodeImage类实现QRCodeImage 供读取时所用
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* @author fangyi
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*
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*/
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public
class MyQRCodeImage implements QRCodeImage {
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BufferedImage bufferedImage ;
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public MyQRCodeImage(BufferedImage bufferedImage) {
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super();
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this.bufferedImage = bufferedImage;
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}
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@Override
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public int getHeight() {
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return bufferedImage.getHeight();
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}
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@Override
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public int getPixel(int arg0, int arg1) {
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return bufferedImage.getRGB(arg0, arg1);
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}
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@Override
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public int getWidth() {
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return bufferedImage.getWidth();
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}
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}
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<%@ page language="java" contentType="text/html; charset=UTF-8"
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pageEncoding=
"UTF-8"
%>
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<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
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<html>
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<head>
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<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
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<title>
生成二维码
</title>
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<!-- js地址https://github.com/jeromeetienne/jquery-qrcode -->
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<script type="text/javascript" src="
<%=request.getContextPath() %>
/js/jquery.min.js"></script>
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<script type="text/javascript" src="
<%=request.getContextPath() %>
/js/jquery.qrcode.min.js"></script>
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</head>
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<body>
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生成二维码如下：
<br>
<br>
<br>
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<div id="qrcode">
</div>
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<script type="text/javascript">
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$(
'#qrcode'
).qrcode(
"www.baidu.com"
);
//生产二维码
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/* jquery('#qrcode').qrcode({width: 64,height: 64,text: "size doesn't matter"}); */
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</script>
-
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</body>
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</html>
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import java.io.File;
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import java.io.IOException;
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import java.util.Hashtable;
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import com.google.zxing.BarcodeFormat;
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import com.google.zxing.EncodeHintType;
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import com.google.zxing.MultiFormatWriter;
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import com.google.zxing.WriterException;
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import com.google.zxing.common.BitMatrix;
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import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
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/**
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* zxing jar包地址 https://github.com/Candy1575/QRcode
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* 依赖MatrixToImageWriter类
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* @author fangyi
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*
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*/
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public
class EncodeTest {
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public static void Encode_QR_CODE() throws IOException, WriterException{
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String contents =
"ZXing 二维码内容1234!";
// 二维码内容
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int width =
430;
// 二维码图片宽度 300
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int height =
430;
// 二维码图片高度300
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String format =
"gif";
// 二维码的图片格式 gif
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Hashtable<EncodeHintType, Object> hints =
new Hashtable<EncodeHintType, Object>();
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// 指定纠错等级,纠错级别（L 7%、M 15%、Q 25%、H 30%）
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hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
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// 内容所使用字符集编码
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hints.put(EncodeHintType.CHARACTER_SET,
"utf-8");
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// hints.put(EncodeHintType.MAX_SIZE, 350);//设置图片的最大值
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// hints.put(EncodeHintType.MIN_SIZE, 100);//设置图片的最小值
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hints.put(EncodeHintType.MARGIN,
1);
//设置二维码边的空度，非负数
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BitMatrix bitMatrix =
new MultiFormatWriter().encode(contents,
//要编码的内容
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//编码类型，目前zxing支持：Aztec 2D,CODABAR 1D format,Code 39 1D,Code 93 1D ,Code 128 1D,
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//Data Matrix 2D , EAN-8 1D,EAN-13 1D,ITF (Interleaved Two of Five) 1D,
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//MaxiCode 2D barcode,PDF417,QR Code 2D,RSS 14,RSS EXPANDED,UPC-A 1D,UPC-E 1D,UPC/EAN extension,UPC_EAN_EXTENSION
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BarcodeFormat.QR_CODE,
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width,
//条形码的宽度
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height,
//条形码的高度
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hints);
//生成条形码时的一些配置,此项可选
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// 生成二维码
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File outputFile =
new File(
"D:" + File.separator +
"mycode.gif");
//指定输出路径
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MatrixToImageWriter.writeToFile(bitMatrix, format, outputFile);
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}
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public static void main(String[] args) throws Exception {
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try {
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Encode_QR_CODE();
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}
catch (Exception e) {
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// TODO: handle exception
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e.printStackTrace();
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}
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}
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}
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-
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import java.awt.image.BufferedImage;
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import java.io.File;
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import java.io.IOException;
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import java.io.OutputStream;
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import javax.imageio.ImageIO;
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import com.google.zxing.common.BitMatrix;
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/**
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* 二维码的生成需要借助MatrixToImageWriter类，
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* 该类是由Google提供的，可以将该类直接拷贝到源码中使用，当然你也可以自己写个
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* 生产条形码的基类 依赖LogoConfig类
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*/
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public
class MatrixToImageWriter {
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private
static
final
int BLACK =
0xFF000000;
//用于设置图案的颜色
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private
static
final
int WHITE =
0xFFFFFFFF;
//用于背景色
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private MatrixToImageWriter() {
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}
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public static BufferedImage toBufferedImage(BitMatrix matrix) {
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int width = matrix.getWidth();
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int height = matrix.getHeight();
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BufferedImage image =
new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
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for (
int x =
0; x < width; x++) {
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for (
int y =
0; y < height; y++) {
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image.setRGB(x, y, (matrix.get(x, y) ? BLACK : WHITE));
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// image.setRGB(x, y, (matrix.get(x, y) ? Color.YELLOW.getRGB() : Color.CYAN.getRGB()));
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}
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}
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return image;
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}
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public static void writeToFile(BitMatrix matrix, String format, File file) throws IOException {
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BufferedImage image = toBufferedImage(matrix);
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//设置logo图标
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LogoConfig logoConfig =
new LogoConfig();
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image = logoConfig.LogoMatrix(image);
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if (!ImageIO.write(image, format, file)) {
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throw
new IOException(
"Could not write an image of format " + format +
" to " + file);
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}
else{
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System.out.println(
"图片生成成功！");
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}
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}
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public static void writeToStream(BitMatrix matrix, String format, OutputStream stream) throws IOException {
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BufferedImage image = toBufferedImage(matrix);
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//设置logo图标
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LogoConfig logoConfig =
new LogoConfig();
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image = logoConfig.LogoMatrix(image);
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if (!ImageIO.write(image, format, stream)) {
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throw
new IOException(
"Could not write an image of format " + format);
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}
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}
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}
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import java.awt.BasicStroke;
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import java.awt.Color;
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import java.awt.Graphics2D;
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import java.awt.geom.RoundRectangle2D;
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import java.awt.image.BufferedImage;
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import java.io.File;
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import java.io.IOException;
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import javax.imageio.ImageIO;
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/**
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* 二维码 添加自定义 logo图标 处理的方法,
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* 模仿微信自动生成二维码效果，有圆角边框，logo和二维码间有空白区，logo带有灰色边框
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* @author fangyi
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*
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*/
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public
class LogoConfig {
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/**
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* 设置 logo
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* @param matrixImage 源二维码图片
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* @return 返回带有logo的二维码图片
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* @throws IOException
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* @author Administrator sangwenhao
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*/
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public BufferedImage LogoMatrix(BufferedImage matrixImage) throws IOException{
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/**
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* 读取二维码图片，并构建绘图对象
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*/
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Graphics2D g2 = matrixImage.createGraphics();
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int matrixWidth = matrixImage.getWidth();
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int matrixHeigh = matrixImage.getHeight();
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/**
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* 读取Logo图片
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*/
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BufferedImage logo = ImageIO.read(
new File(
"C:\\Users\\fangyi\\Pictures\\code-wallpaper-18.png"));
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//开始绘制图片
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g2.drawImage(logo,matrixWidth/
5*
2,matrixHeigh/
5*
2, matrixWidth/
5, matrixHeigh/
5,
null);
//绘制
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BasicStroke stroke =
new BasicStroke(
5,BasicStroke.CAP_ROUND,BasicStroke.JOIN_ROUND);
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g2.setStroke(stroke);
// 设置笔画对象
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//指定弧度的圆角矩形
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RoundRectangle2D.Float round =
new RoundRectangle2D.Float(matrixWidth/
5*
2, matrixHeigh/
5*
2, matrixWidth/
5, matrixHeigh/
5,
20,
20);
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g2.setColor(Color.white);
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g2.draw(round);
// 绘制圆弧矩形
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//设置logo 有一道灰色边框
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BasicStroke stroke2 =
new BasicStroke(
1,BasicStroke.CAP_ROUND,BasicStroke.JOIN_ROUND);
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g2.setStroke(stroke2);
// 设置笔画对象
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RoundRectangle2D.Float round2 =
new RoundRectangle2D.Float(matrixWidth/
5*
2+
2, matrixHeigh/
5*
2+
2, matrixWidth/
5-
4, matrixHeigh/
5-
4,
20,
20);
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g2.setColor(
new Color(
128,
128,
128));
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g2.draw(round2);
// 绘制圆弧矩形
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g2.dispose();
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matrixImage.flush() ;
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return matrixImage ;
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}
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}
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import java.awt.image.BufferedImage;
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import java.io.File;
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import java.io.IOException;
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import java.util.HashMap;
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import java.util.Map;
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import javax.imageio.ImageIO;
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import com.google.zxing.Binarizer;
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import com.google.zxing.BinaryBitmap;
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import com.google.zxing.EncodeHintType;
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import com.google.zxing.LuminanceSource;
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import com.google.zxing.MultiFormatReader;
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import com.google.zxing.NotFoundException;
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import com.google.zxing.Result;
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import com.google.zxing.client.j2se.BufferedImageLuminanceSource;
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import com.google.zxing.common.BitArray;
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import com.google.zxing.common.BitMatrix;
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import com.google.zxing.common.HybridBinarizer;
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-
/**
-
* 读取zxing类型下的二维码信息
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* @author fangyi
-
*
-
*/
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public
class ReadQrCode_Zxing {
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-
@SuppressWarnings(
"unchecked")
-
public static void main(String[] args) {
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try {
-
MultiFormatReader formatReader =
new MultiFormatReader();
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//读取指定的二维码文件
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File file=
new File(
"D:\\mycode.gif");
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BufferedImage bufferedImage =ImageIO.read(file);
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BinaryBitmap binaryBitmap=
new BinaryBitmap(
new HybridBinarizer(
new BufferedImageLuminanceSource(bufferedImage)));
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//定义二维码参数
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Map hints=
new HashMap<>();
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hints.put(EncodeHintType.CHARACTER_SET,
"utf-8");
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Result result = formatReader.decode(binaryBitmap, hints);
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//输出相关的二维码信息
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System.out.println(
"解析结果"+result.toString());
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System.out.println(
"二维码格式类型"+result.getBarcodeFormat());
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System.out.println(
"二维码文本内容"+result.getText());
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bufferedImage.flush();
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}
catch (NotFoundException e) {
-
e.printStackTrace();
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}
catch (IOException e) {
-
e.printStackTrace();
-
}
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}
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}
用二维码进行添加好友获取好友信息是用到VCard
微信扫码登陆网页原理：通过堵塞等待的长连接，近乎实时的获得信息。 对于验证过程，Open API 一般是通过授权令牌（Token）来解决的，原理是当用户通过授权后，分配一个限定条件下的令牌（如限制本机访问、限制授权有效时间、限制同时登录设备数等），使获得授权的用户仅在有限的前提下能访问相关服务。 像计算机休眠后曾做的授权就自动收回了，这样就有效的避免了在别人电脑上（尤其是网吧）打开，但忘记关闭或退出这类安全问题了。
实现可借鉴已有博客：https://www.cnblogs.com/zijun/p/3580125.html