第四次作业
<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>$Title$</title> </head> <script type="text/javascript"> function reloadCode() { var time=new Date().getTime(); document.getElementById("imagecode").src="<%= request.getContextPath()%>/servlet/ImageServlet?d="+time; } </script> <body> <form action="<%= request.getContextPath()%>/servlet/UserServlet" method="post" > 用户名:<input type="text" name="uname"/> <br> 密码:<input type="password" name="password"/> <br> 验证码:<input type="text" name="checkCode"/> <a href="javascript:reloadCode();"> <img alt="验证码" id="imagecode" src="<%= request.getContextPath()%>/servlet/ImageServlet"/> 不太清楚</a><br> <input type="submit" value="登录"> </form> </body> </html>
<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>Title</title> </head> <body> <h2 style="color: cadetblue">登录成功！！！！！！！！</h2> </body> </html>
package servlet;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
@WebServlet(urlPatterns="/servlet/UserServlet")
public class UserServlet extends HttpServlet {
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doPost(request, response);
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
System.out.println("do Post");
String uname = request.getParameter("uname");
String password = request.getParameter("password");
System.out.println(uname+"----"+password);
String piccode=(String) request.getSession().getAttribute("piccode");
String checkCode=request.getParameter("checkCode");
checkCode=checkCode.toUpperCase();
response.setContentType("text/html;charset=gbk");
PrintWriter out=response.getWriter();
if(checkCode.equals(piccode) && "lty".equals(uname) && "123456".equals(password))
{
String contextPath = request.getContextPath();
response.sendRedirect(contextPath+"/ok.jsp");
}
else
{
request.getRequestDispatcher("/index.jsp").forward(request, response);
}
out.flush();
out.close();
}
}
package servlet; import java.awt.Color; import java.awt.Graphics; import java.awt.image.BufferedImage; import java.io.IOException; import java.util.Random; import javax.imageio.ImageIO; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; @WebServlet(urlPatterns="/servlet/ImageServlet") public class ImageServlet extends HttpServlet{ public void doGet(HttpServletRequest request,HttpServletResponse response) throws IOException{ //这个方法实现验证码的生成 BufferedImage bi=new BufferedImage(68, 22,BufferedImage.TYPE_INT_RGB);//创建图像缓冲区 Graphics g=bi.getGraphics(); //通过缓冲区创建一个画布 Color c=new Color(253, 161,255); //创建颜色 /*根据背景画了一个矩形框 */ g.setColor(c);//为画布创建背景颜色 g.fillRect(0, 0, 68,22); //fillRect:填充指定的矩形 char[] ch="ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789".toCharArray();//转化为字符型的数组 Random r=new Random(); int len=ch.length; int index; //index用于存放随机数字 StringBuffer sb=new StringBuffer(); for(int i=0;i<4；i++)
{ index=r.nextInt(len); g.setColor(new Color(r.nextInt(88),r.nextInt(188),r.nextInt(255))); g.drawString(ch[index]+"",(i*15)+3, 18); sb.append(ch[index]); } request.getSession().setAttribute("piccode",sb.toString()); ImageIO.write(bi, "JPG", response.getOutputStream()); }}
