登录页面练习servlet

登录练习：
1创建登录页面
　　　　创建servlet进行登录页面请求
2点击登录完成操作
　　　　浏览器发送请求到服务器（用户信息+其他数据）
3服务器调用对应的servlet进行处理
　　　　设置响应编码格式
　　　　获取请求信息
　　　　处理请求信息
　　　　响应处理结果
4在servlet中完成登录校验
　　　　需要连接数据库(需要创建用户）

　　使用mvc思想

1、创建登录页面

package com.bjsxt.servlet;

import java.io.IOException;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import com.sun.mail.handlers.text_html;

public class PageServlet extends HttpServlet {

	@Override

	protected void service(HttpServletRequest req, HttpServletResponse resp)

			throws ServletException, IOException {

		//设置响应编码格式、

		resp.setContentType("text/html;charset=utf-8");

		//获取请求信息

		resp.getWriter().write("<html>");

		resp.getWriter().write("<head>");

		resp.getWriter().write("</head>");

		resp.getWriter().write("<body>");

		resp.getWriter().write("<form action='login' method='get'>");

		resp.getWriter().write("用户名:<input type='text' name='uname' value=''><br/>" );

		resp.getWriter().write("密码:<input type='password' name='pwd' value=''><br/>" );

		resp.getWriter().write("<input type='submit'  value='提交'><br/>" );

		resp.getWriter().write("</form>");

		resp.getWriter().write("</body>");

		resp.getWriter().write("</html>");

		//处理请求

		//响应请求结果

	}

}

登录服务器

loginservlet

package com.bjsxt.servlet;

import java.io.IOException;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import com.bjsxt.pojo.User;

import com.bjsxt.service.LoginService;

import com.bjsxt.service.impl.LoginServicelmpl;

public class LoginServlet extends HttpServlet {

	@Override

	protected void service(HttpServletRequest req, HttpServletResponse resp)

			throws ServletException, IOException {

		//设置响应编码格式

		resp.setContentType("text/html;charset=utf-8");

		//获取请求信息

		String uname=req.getParameter("uname");

		String pwd=req.getParameter("pwd");

		System.out.println(uname+":"+pwd);

		//处理请求信息

			//获取业务层信息

		LoginService ls=new LoginServicelmpl();

		User u=ls.checkLoginService(uname, pwd);

		System.out.println(u);

		//响应处理结果

		if(u!=null){

			resp.getWriter().write("登录成功");

		}else{

			resp.getWriter().write("登录失败");

		}

	}

}

service下面写接口

 package com.bjsxt.service;

import com.bjsxt.pojo.User;

public interface LoginService {

	User checkLoginService(String uname,String pwd);

}

　　建立实体类专门用来存用户数据

package com.bjsxt.pojo;

public class User {

	private int uid;//数据名要和数据库中的字段名要保持一致

	private String uname;

	private String pwd;

	public int getUid() {

		return uid;

	}

	public void setUid(int uid) {

		this.uid = uid;

	}

	public String getUname() {

		return uname;

	}

	public void setUname(String uname) {

		this.uname = uname;

	}

	public String getPwd() {

		return pwd;

	}

	public void setPwd(String pwd) {

		this.pwd = pwd;

	}

	@Override

	public String toString() {

		return "User [uid=" + uid + ", uname=" + uname + ", pwd=" + pwd + "]";

	}

	@Override

	public int hashCode() {

		final int prime = 31;

		int result = 1;

		result = prime * result + ((pwd == null) ? 0 : pwd.hashCode());

		result = prime * result + uid;

		result = prime * result + ((uname == null) ? 0 : uname.hashCode());

		return result;

	}

	@Override

	public boolean equals(Object obj) {

		if (this == obj)

			return true;

		if (obj == null)

			return false;

		if (getClass() != obj.getClass())

			return false;

		User other = (User) obj;

		if (pwd == null) {

			if (other.pwd != null)

				return false;

		} else if (!pwd.equals(other.pwd))

			return false;

		if (uid != other.uid)

			return false;

		if (uname == null) {

			if (other.uname != null)

				return false;

		} else if (!uname.equals(other.uname))

			return false;

		return true;

	}

  public User(){

	  super();

  }

  public User(int uid,String uname,String pwd){

	  super();

	  this.uid=uid;

	  this.uname=uname;

	  this.pwd=pwd;

  }	

}

　　实现类

过度翻转

package com.bjsxt.service.impl;

import com.bjsxt.dao.LoginDao;

import com.bjsxt.dao.impl.LoginDaImpl;

import com.bjsxt.pojo.User;

import com.bjsxt.service.LoginService;

public class LoginServicelmpl implements LoginService{

	//创建DAO层对象

	LoginDao Id=new LoginDaImpl();

	@Override

	public User checkLoginService(String uname, String pwd) {

		// TODO Auto-generated method stub

		return Id.checkLoginDao(uname, pwd);

	}

}

　　直接浏览数据到操作层

package com.bjsxt.dao;

import com.bjsxt.pojo.User;

public interface LoginDao {

	User checkLoginDao(String uname,String pwd);

}

　　数据库层的接口

package com.bjsxt.dao.impl;

import java.sql.DriverManager;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.SQLException;

import javax.crypto.spec.PSource;

import com.bjsxt.dao.LoginDao;

import com.bjsxt.pojo.User;

import com.mysql.jdbc.Connection;

public class LoginDaImpl implements LoginDao{

	@Override

	public User checkLoginDao(String uname, String pwd) {

		//声明jdbc对象

		java.sql.Connection conn=null;

		PreparedStatement ps=null;

		ResultSet rs=null;

		//声明数据存储对象

		User u=null;

		try {

			//加载驱动

			Class.forName("com.mysql.jdbc.Driver");

			//获取链接对象

			conn=DriverManager.getConnection("jdbc:mysql://localhost:3306/407", "root", "root");

			//创建SQL 命令

			String sql="select * from t_user where uname=? and pwd=?";

			//创建Sql命令对象

			ps=conn.prepareStatement(sql);

			//给占位符赋值

			ps.setString(1, uname);

			ps.setString(2, pwd);

			//执行

			rs=ps.executeQuery();

			//遍历执行结果

			while(rs.next())

			{

				u=new User();

				u.setUid(rs.getInt("uid"));

				u.setUname(rs.getString("uname"));

				u.setPwd(rs.getString("pwd"));

			}

			//关闭资源

		} catch (Exception e) {

			e.printStackTrace();

			// TODO: handle exception

		}finally{

			try {

				rs.close();

			} catch (SQLException e) {

				// TODO Auto-generated catch block

				e.printStackTrace();

			}

			try {

				ps.close();

			} catch (SQLException e) {

				// TODO Auto-generated catch block

				e.printStackTrace();

			}

			try {

				conn.close();

			} catch (SQLException e) {

				// TODO Auto-generated catch block

				e.printStackTrace();

			}

		}

		//返回

		return u;

	}

}

　　记得要拿jar包放入到lib文件夹中

巴特西

登录页面练习servlet

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