loginaction.java

JSP做的 登陆查找添加页面适合初学者模仿练习小的应用程序！

package Servlet;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.Vector;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import Bean.GetStudent;

public class loginAction extends HttpServlet {

	/**
	 * Constructor of the object.
	 */
	public loginAction() {
		super();
	}

	/**
	 * Destruction of the servlet. <br>
	 */
	public void destroy() {
		super.destroy(); // Just puts "destroy" string in log
		// Put your code here
	}

	/**
	 * The doPost method of the servlet. <br>
	 *
	 * This method is called when a form has its tag value method equals to post.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 */
	public void doPost(HttpServletRequest request, HttpServletResponse response) {

		response.setContentType("text/html");
		String studentId=request.getParameter("studentId");
		String password=request.getParameter("Password");
		String sql="select * from student where studentid='"
			+studentId+"' and password='"+password+"'";
		GetStudent getStudent=new GetStudent();
		try {
			Vector vec=getStudent.getData(sql);
			if(vec.size()==0)
			{
				String msg="用户名或密码错误!";
				request.setAttribute("msg", msg);
				RequestDispatcher rd=request.getRequestDispatcher("login.jsp");
				rd.forward(request, response);
			}
			else
			{
				request.setAttribute("vec", vec);
				RequestDispatcher rd=request.getRequestDispatcher("main.jsp");
				rd.forward(request, response);
			}
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
		
		
	}

	/**
	 * Initialization of the servlet. <br>
	 *
	 * @throws ServletException if an error occure
	 */
	public void init() throws ServletException {
		// Put your code here
	}

}