JavaWeb -- Session应用实例 -- 随机中文验证码 检验
注册页面 login.html
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<title>Insert title here</title>
<script type="text/javascript">
function changeImage(img) {
img.src = img.src + "?" + new Date().getTime();
}
</script>
</head>
<body>
<form action="/WebTest3/Demo9" method="get">
<pre>
User :<input type="text" name="username"/> <br />
Passwd :<input type="password" name="passwd"/> <br />
CheckCode:<input type="text" name="checkcode"/> <br />
<img src="/WebTest3/Demo8" alt="ChangeOne" onclick="changeImage(this)" style="cursor: hand"/> <br />
Submit<input type="submit" name="submit" value="submit"/>
</pre>
</form>
</body>
</html>
随机中文图片生成Servlet
public class Demo8 extends HttpServlet {
private static final long serialVersionUID = 1L;
private static final int width = 120;
private static final int height = 40;
/**
* @see HttpServlet#HttpServlet()
*/
public Demo8() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
Graphics g = image.getGraphics();
setBackGround(g);
setBorder(g);
drawRandomLine(g);
String random = drawRandomNum((Graphics2D)g);
request.getSession().setAttribute("checkcode", random);
response.setContentType("image/jpeg");
response.setDateHeader("expries", -1);
response.setHeader("Cache-Control", "no-cache");
response.setHeader("Pragma", "no-cache");
ImageIO.write(image, "jpg", response.getOutputStream());
}
private String drawRandomNum(Graphics2D g) {
// TODO Auto-generated method stub
//[\u4e00 ~ \u9fa5]
g.setColor(Color.BLUE);
g.setFont(new Font(null, Font.BOLD, 20));
String base = "\u7684\u4e00\u662f\u4e86\u6211\u4e0d\u4eba\u5728\u4ed6\u6709\u8fd9\u4e2a\u4e0a\u4eec\u6765";
int x = 5;
StringBuffer sb = new StringBuffer();
for(int i=0; i<4; i++)
{
String ch = base.charAt(new Random().nextInt(base.length())) + "";
//System.out.println(ch);
sb.append(ch);
int degreen = new Random().nextInt()%30;
g.rotate(degreen*Math.PI/180, x, 25);
g.drawString(ch, x, 25);
g.rotate(-degreen*Math.PI/180, x, 25);
x += 30;
}
return sb.toString();
}
private void drawRandomLine(Graphics g) {
// TODO Auto-generated method stub
g.setColor(Color.green);
for(int i=0; i<8; i++)
{
int x1 = new Random().nextInt(width);
int y1 = new Random().nextInt(height);
int x2 = new Random().nextInt(width);
int y2 = new Random().nextInt(height);
g.drawLine(x1, y1, x2, y2);
}
}
private void setBorder(Graphics g) {
// TODO Auto-generated method stub
g.setColor(Color.blue);
g.drawRect(1, 1, width-2, height-2);
}
private void setBackGround(Graphics g) {
// TODO Auto-generated method stub
g.setColor(Color.WHITE);
g.fillRect(0, 0, width, height);
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
}
}
检验验证码正确性Servlet
public class Demo9 extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public Demo9() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
request.setCharacterEncoding("UTF-8");
response.setCharacterEncoding("UTF-8");
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
String c_checkcode_temp = request.getParameter("checkcode");
String c_checkcode = new String(c_checkcode_temp.getBytes("iso8859-1"), "UTF-8"); //防乱码
String s_checkcode = (String) request.getSession().getAttribute("checkcode");
out.println("c_code: " + c_checkcode + "s_code: " + s_checkcode);
if(c_checkcode!=null && s_checkcode!=null && c_checkcode.equals(s_checkcode))
{
out.println("checkcode is right");
}
else
{
out.println("checkcode is wrong");
}
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
}
}
