Myeclipse+jdk+tomcat+mysql环境搭建

用户名：

密码：

4.2在src中新建类，包名：servlet类名：HomePageAction点击完成。代码如下：

packageservlet;

importjava.io.IOException;

importjava.sql.*;//导入数据库处理所有库

importjavax.servlet.ServletConfig;

importjavax.servlet.ServletException;

importjavax.servlet.http.HttpServlet;

importjavax.servlet.http.HttpServletRequest;

importjavax.servlet.http.HttpServletResponse;

importjavax.swing.JOptionPane;

//用户登录处理Servlet系统登录主页处理表单

publicclassHomePageActionextendsHttpServlet {

privateConnectioncn=null;//定义数据库连接对象

privateStringdriverName=null;//数据库驱动器

privateStringurl=null;//数据库地址URL

//初始化方法，取得数据库连接对象

publicvoidinit(ServletConfig config)throwsServletException

{

super.init(config);

driverName=config.getInitParameter("driverName");

url=config.getInitParameter("url");

try{

//加载驱动程序

Class.forName(driverName);

//连接数据库

cn=DriverManager.getConnection(url,"root","root");

}catch(Exception e) {

System.out.println("取得数据库连接错误："+e.getMessage());

}

}

//处理GET请求方法

publicvoiddoGet(HttpServletRequest request, HttpServletResponse response)

throwsServletException, IOException

{

//取得用户注册表单提交的数据

String userid=request.getParameter("userid");

String password=request.getParameter("password");

//判断登录账号为空，则自动跳转到注册页面

if(userid==null||userid.trim().length()==0) {

response.sendRedirect("index.jsp");

JOptionPane.showMessageDialog(null,"User name or password can't be empty!");

}