二維碼分為好多種，我們最常用的是qrcode類型的二維碼，以下有三種生成方式以及解析方式：
附所需jar包或者js地址
第一種：依賴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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/**獲取qrcode jar包 https://osdn.jp/projects/qrcode
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* 生成qrcode二維碼
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* @author fangyi
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*
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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');
//糾錯等級
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qrcode.setQrcodeEncodeMode(
'B');
//N代表數字 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";
//二維碼信息內容
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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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//畫圖工具
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Graphics2D gs= bufferedImage.createGraphics();
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//設置屬性
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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");
//編碼防止有中文
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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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//關閉資源，並保存文件
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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"));
//輸出到指定地方
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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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* 讀取制定路徑下的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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//指定的二維碼文件路徑
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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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//輸出結果
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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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* 自定義QRCodeImage類實現QRCodeImage 供讀取時所用
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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>
生成二維碼
</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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生成二維碼如下：
<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"
);
//生產二維碼
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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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* 依賴MatrixToImageWriter類
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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 二維碼內容1234!";
// 二維碼內容
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int width =
430;
// 二維碼圖片寬度 300
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int height =
430;
// 二維碼圖片高度300
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String format =
"gif";
// 二維碼的圖片格式 gif
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Hashtable<EncodeHintType, Object> hints =
new Hashtable<EncodeHintType, Object>();
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// 指定糾錯等級,糾錯級別（L 7%、M 15%、Q 25%、H 30%）
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hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
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// 內容所使用字符集編碼
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hints.put(EncodeHintType.CHARACTER_SET,
"utf-8");
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// hints.put(EncodeHintType.MAX_SIZE, 350);//設置圖片的最大值
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// hints.put(EncodeHintType.MIN_SIZE, 100);//設置圖片的最小值
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hints.put(EncodeHintType.MARGIN,
1);
//設置二維碼邊的空度，非負數
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BitMatrix bitMatrix =
new MultiFormatWriter().encode(contents,
//要編碼的內容
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//編碼類型，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,
//條形碼的寬度
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height,
//條形碼的高度
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hints);
//生成條形碼時的一些配置,此項可選
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// 生成二維碼
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File outputFile =
new File(
"D:" + File.separator +
"mycode.gif");
//指定輸出路徑
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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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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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* 二維碼的生成需要借助MatrixToImageWriter類，
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* 該類是由Google提供的，可以將該類直接拷貝到源碼中使用，當然你也可以自己寫個
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* 生產條形碼的基類 依賴LogoConfig類
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*/
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public
class MatrixToImageWriter {
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private
static
final
int BLACK =
0xFF000000;
//用於設置圖案的顏色
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private
static
final
int WHITE =
0xFFFFFFFF;
//用於背景色
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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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//設置logo圖標
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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(
"圖片生成成功！");
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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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//設置logo圖標
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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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* 二維碼 添加自定義 logo圖標 處理的方法,
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* 模仿微信自動生成二維碼效果，有圓角邊框，logo和二維碼間有空白區，logo帶有灰色邊框
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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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* 設置 logo
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* @param matrixImage 源二維碼圖片
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* @return 返回帶有logo的二維碼圖片
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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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* 讀取二維碼圖片，並構建繪圖對象
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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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* 讀取Logo圖片
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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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//開始繪制圖片
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g2.drawImage(logo,matrixWidth/
5*
2,matrixHeigh/
5*
2, matrixWidth/
5, matrixHeigh/
5,
null);
//繪制
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BasicStroke stroke =
new BasicStroke(
5,BasicStroke.CAP_ROUND,BasicStroke.JOIN_ROUND);
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g2.setStroke(stroke);
// 設置筆畫對象
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//指定弧度的圓角矩形
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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);
// 繪制圓弧矩形
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//設置logo 有一道灰色邊框
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BasicStroke stroke2 =
new BasicStroke(
1,BasicStroke.CAP_ROUND,BasicStroke.JOIN_ROUND);
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g2.setStroke(stroke2);
// 設置筆畫對象
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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);
// 繪制圓弧矩形
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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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/**
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* 讀取zxing類型下的二維碼信息
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* @author fangyi
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*
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*/
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public
class ReadQrCode_Zxing {
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@SuppressWarnings(
"unchecked")
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public static void main(String[] args) {
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try {
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MultiFormatReader formatReader =
new MultiFormatReader();
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//讀取指定的二維碼文件
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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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//定義二維碼參數
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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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//輸出相關的二維碼信息
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System.out.println(
"解析結果"+result.toString());
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System.out.println(
"二維碼格式類型"+result.getBarcodeFormat());
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System.out.println(
"二維碼文本內容"+result.getText());
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bufferedImage.flush();
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}
catch (NotFoundException e) {
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e.printStackTrace();
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}
catch (IOException e) {
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e.printStackTrace();
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}
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}
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}
用二維碼進行添加好友獲取好友信息是用到VCard
微信掃碼登陸網頁原理：通過堵塞等待的長連接，近乎實時的獲得信息。 對於驗證過程，Open API 一般是通過授權令牌（Token）來解決的，原理是當用戶通過授權后，分配一個限定條件下的令牌（如限制本機訪問、限制授權有效時間、限制同時登錄設備數等），使獲得授權的用戶僅在有限的前提下能訪問相關服務。 像計算機休眠后曾做的授權就自動收回了，這樣就有效的避免了在別人電腦上（尤其是網吧）打開，但忘記關閉或退出這類安全問題了。
實現可借鑒已有博客：https://www.cnblogs.com/zijun/p/3580125.html