empservlet.java

宠物诊所的JAVA-WEB实现

package com.hellofdeath.loginAndExit;

import java.io.IOException;
import java.io.PrintWriter;
import java.sql.ResultSet;
import java.sql.SQLException;

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

import com.hellofdeath.tool.DBUtils;


public class EmpServlet extends HttpServlet {

	private static final long serialVersionUID = 3011821591580465264L;

	public void init() throws ServletException {

	}
	public EmpServlet() {
		super();
	}

	public void destroy() {
		super.destroy(); 
	}

	public void doGet(HttpServletRequest request, HttpServletResponse response)
	throws ServletException, IOException {
		this.doPost(request,response);
	}
	
	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		
		response.setContentType("text/html;charset=GBK");
		request.setCharacterEncoding("GBK");
		session=request.getSession();//创建一个新的会话		
		action=request.getParameter("action");
		session.setAttribute("isLogin","false");
		//判断进行什么操作
		if(action.equals("登录")){
			this.check(request,response);
		}
		else if(action.equals("exit")){
			session.invalidate();
			//转到登陆界面
			response.sendRedirect("/PetClinic/index.html");
			/*一直准备用 请求转发的,可是相同的代码在别的机器上可以用
			 * 在我的机器上就经常报告找不到页面
			 * 不知道是IE还是系统,重装一次,故障依旧,
			 * 郁闷了,只好一直用 重定向~~~~~
			 */
		}
	}
	
	//检查用户名和密码是否正确
	public void check(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException{
		PrintWriter out = response.getWriter();
		name=request.getParameter("name");//获取姓名和密码
		password=request.getParameter("password");
		
		strSql="select * from employee where name='"+name+"' and password='"+password+"'";
		//查询数据库中是否有对应的数据		
		rs=dbu.getResultSet(strSql);
		//获取查询的结果集
		try {
			if(rs.next()){
				session.setAttribute("isLogin","true");//登陆成功,纪录进入会话
				response.sendRedirect("/PetClinic/vet/vetSearch.jsp");
			}
			else{
				session.setAttribute("isLogin","false");//登陆失败,纪录进入会话
				out.println("<p align=center><h3>登陆失败</h3>");
				out.println("<p align=center><a href=\"/PetClinic/index.html\">返回");//返回登陆页面
			}
			dbu.close();
		} catch (SQLException e) {
			System.out.println(e.getMessage());
		}
		out.flush();
		out.close();
	}

	private HttpSession session=null;
	private String action=null; 
	private String name=null;
	private String password=null;
	private String strSql=null;
	private DBUtils dbu=new DBUtils();
	private ResultSet rs=null;
}