手把手教你生成二维码-google.zxing

一、目标

输入网址，生成网址的二维码

二、概况

1.效果：UI丑，但功能实现了

2.项目目录

三、用到的第三方资源

1.google的扫码包zxing

2.JQuery

四、步骤(用myEclipse)

1.新建工程,选择web project

2.加入第三方资源(zxing包和jQuery)

2.1

2.1.1复制，粘贴，加入zxing的jar包(所有文件在附件中下载)

2.2.2右键jar包加入buildpath

2.2加入jQuery文件

2.2.1在WebRoot下新建文件夹js

复制粘贴jQuery文件到此文件夹

3.按需求修改webroot下的index.jsp页面如下：

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
 
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    <title>二维码</title>
    <script src="js/jquery.min.js"></script>
    <script>
        $(function(){
            $("input[type=submit]").click(function(e){
                e.preventDefault();
                $("#qrcode_div").empty().append("<img id='qrImg' />");
                $("#qrImg").attr("src", "qrcode?website="+$("input[type=text][name=website]").val());//此处会访问servlet
            });
        });
    </script>
  </head>
   
  <body>
    <form>
        网址<input type="text" name="website" />
        <input type="submit" value="生成二维码" />
        <div id="qrcode_div"></div>
    </form>
  </body>
</html>

4.新建servlet文件

4.1右键工程文件夹--》new ---->servlet（myEclipse会自动配置servlet到web.xml文件）

QRCode.java servlet文件的代码如下：

package servlet;
import java.io.IOException;
 
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
 
import util.QRCodeUtil;
 
import com.google.zxing.WriterException;
 
 
public class QRCode extends HttpServlet {
     
    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
         
        request.setCharacterEncoding("utf-8");
        response.setCharacterEncoding("utf-8");
        String website = request.getParameter("website");
        try {
            QRCodeUtil.genGR(website, response.getOutputStream());
        } catch (WriterException e) {
            e.printStackTrace();
        }
        //String website = request.getAttribute("website").toString();
    }
 
    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doGet(request, response);
    }
 
}

5.新建辅助类文件，作用是生成二维码（QRCodeUtil.java）

5.1右键工程文件夹--》new--->class,如下图

QRCodeUtil.java的代码如下：

package util2;
 
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Hashtable;
 
import javax.imageio.ImageIO;
 
import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.WriterException;
import com.google.zxing.common.BitMatrix;
 
public class QRCodeUtil {
     
    private static final int BLACK = 0xFF000000;
    private static final int WHITE = 0xFFFFFFFF;
     
    public static void genGR(String website, OutputStream output) throws WriterException, IOException {
        int width = 300;
        int height = 300;
        String format = "jpg";
        Hashtable<EncodeHintType, String> hints = new Hashtable<EncodeHintType, String>(); 
        //Hashtable hints = new Hashtable();
        hints.put(EncodeHintType.CHARACTER_SET, "utf-8");
        BitMatrix bm = new MultiFormatWriter().encode(website, BarcodeFormat.QR_CODE, width, height, hints);
         
        BufferedImage image = toImage(bm);
        ImageIO.write(image, format, output);   //把二维码写到response的输出流
    }
 
    private static BufferedImage toImage(BitMatrix bm) {
        int width = bm.getWidth();
        int height = bm.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, bm.get(x, y) ? BLACK : WHITE);
            }
        }
        return image;
    }
 
}

6.至此，所有文件已完成，接下来布置项目，启动tomcat，访问文件，如下图

布置完成后，点击debug启动项目

启动成功后，在浏览器中访问文件

PS:

可以修改QRCodeUtil.java文件中的颜色配置，以生成彩色的二维码，例如：

private static final int BLACK = 0xff0000ff;//0xFF000000;
private static final int WHITE = 0xffffff00;//0xFFFFFFFF;

常见颜色代码如下：

这些颜色常数是定义在android.graphics.Color里的：

类型	常数	值	色码
int	BLACK	-16777216	0xff000000
int	BLUE	-16776961	0xff0000ff
int	CYAN	-16711681	0xff00ffff
int	DKGRAY	-12303292	0xff444444
int	GRAY	-7829368	0xff888888
int	GREEN	-16711936	0xff00ff00
int	LTGRAY	-3355444	0xffcccccc
int	MAGENTA	-65281	0xffff00ff
int	RED	-65536	0xffff0000
int	TRANSPARENT	0	0x00000000
int	WHITE	-1	0xffffffff
int	YELLOW	-256	0xffffff00

项目附件：

http://files.cnblogs.com/files/shamgod/QRCode.zip