servlet入门实例:servlet验证登录用户名和密码

来源：互联网发布：js删除dom元素编辑：程序博客网时间：2024/05/23 00:37

登录页面login.html：

web.xml文件部署servlet:

<servlet>
<servlet-name>LoginCheck</servlet-name>
<servlet-class>com.my.servlet.LoginCheck</servlet-class>
</servlet>

<servlet-mapping>
<servlet-name>LoginCheck</servlet-name>
<url-pattern>/LoginCheck</url-pattern>
</servlet-mapping>

LoginCheck.java (servlet)

package com.my.servlet;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class LoginCheck extends HttpServlet {

public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {

response.setContentType("text/html");
PrintWriter out = response.getWriter();
out
.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
out.println("<HTML>");
out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
out.println(" <BODY>");
out.print(" This is ");
out.print(this.getClass());
out.println(", using the GET method");
out.println(" </BODY>");
out.println("</HTML>");
out.flush();
out.close();
}

public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {

response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
String name=request.getParameter("username");
String password=request.getParameter("password");
out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
out.println("<HTML>");
out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
out.println(" <BODY>");
if("www.xin126.cn".equals(name)&&"123".equals(password))
{
out.print("欢迎你"+name);
}
else
{
out.print(" 用户名或密码不对！ ");
}
out.println(" </BODY>");
out.println("</HTML>");
out.flush();
out.close();
}
}