20151210--MVC

package com.hanqi;

import java.io.IOException;
import java.sql.*;
import java.text.SimpleDateFormat;

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

import org.omg.PortableInterceptor.RequestInfoOperations;

import com.hanqi.*;
import com.hanqi.dao.User;
import com.hanqi.dao.UserDal;

import java.util.*;
import java.util.Date;
/**
 * Servlet implementation class SaveUser
 */
public class SaveUser extends HttpServlet {
    private static final long serialVersionUID = 1L;
    private User user;

    /**
     * @see HttpServlet#HttpServlet()
     */
    public SaveUser() {
        super();
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        //转码，固定写法
        request.setCharacterEncoding("UTF-8");
        response.setContentType("text/html;charset=UTF-8");
        response.setCharacterEncoding("UTF-8");    

        Date dt = new Date();//获取当前时间
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");//格式化时间
        String sj = sdf.format(dt);//将时间转换为字符串格式

        //获取内容
        String userID = request.getParameter("userid");
        String userName = request.getParameter("username");
        String pw = request.getParameter("password");
        //判断输入的内容
        if(userID == null || userID.trim().length() == 0)
        {
            //输出内容
            response.getWriter().append("用户代码不能为空");
        }
        else if(userName == null || userName.trim().length() == 0)
        {
            response.getWriter().append("用户姓名不能为空");
        }
        else
        {

            User user = new User();

            user.setUserid(userID);
            user.setUsername(userName);
            user.setPassword(pw);
            user.setuserTime(sj);

            //调用模型层

            UserDal ud = new UserDal();

            try {

                ud.insert(user);

                response.sendRedirect("FindUserList");

            } catch (Exception e) {

                response.getWriter().append("保存数据失败");

                e.printStackTrace();
            }
            }
    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        doGet(request, response);
    }

}

增加

package com.hanqi;

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.hanqi.common.DBHelper;

import java.sql.*;
import java.util.Date;
import com.hanqi.dao.*;

/**
 * Servlet implementation class DeleteUser
 */
public class DeleteUser extends HttpServlet {
    private static final long serialVersionUID = 1L;

    /**
     * @see HttpServlet#HttpServlet()
     */
    public DeleteUser() {
        super();
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        //转码
                request.setCharacterEncoding("UTF-8");
                response.setContentType("text/html;charset=UTF-8");
                response.setCharacterEncoding("UTF-8");    

                String userid = request.getParameter("userid");
                if(userid != null && userid.trim().length() > 0)
                {
                    UserDal ud = new UserDal();

                    try {

                        ud.delete(userid);

                        response.sendRedirect("FindUserList");

                    } catch (Exception e) {

                        response.getWriter().append("删除数据失败");

                        e.printStackTrace();
                    }
                }
}

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        doGet(request, response);
    }

}

删除

package com.hanqi;

import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;

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

import com.hanqi.common.DBHelper;
import com.hanqi.dao.User;
import com.hanqi.dao.UserDal;

/**
 * Servlet implementation class EditUser
 */
public class EditUser extends HttpServlet {
    private static final long serialVersionUID = 1L;

    /**
     * @see HttpServlet#HttpServlet()
     */
    public EditUser() {
        super();
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        request.setCharacterEncoding("UTF-8");
        response.setContentType("text/html;charset=UTF-8");
        response.setCharacterEncoding("UTF-8");    

        //接受相关参数
        String userID = request.getParameter("userid");
        String userName = request.getParameter("username");
        String pw = request.getParameter("password");
        //判断输入的内容
                if(userID == null || userID.trim().length() == 0)
                {
                    //输出内容
                    response.getWriter().append("用户代码不能为空");
                }
                else if(userName == null || userName.trim().length() == 0)
                {
                    response.getWriter().append("用户姓名不能为空");
                }
                else
                {
                    User user = new User();

                    user.setUserid(userID);
                    user.setUsername(userName);
                    user.setPassword(pw);

                    UserDal ud = new UserDal();

                    try
                    {

                        ud.update(user);

                        response.sendRedirect("FindUserList");

                    }
                    catch(Exception e)
                    {

                        response.getWriter().append("修改数据失败");

                        e.printStackTrace();
                    }
                    }

    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        doGet(request, response);
    }

}

修改

        package com.hanqi;

import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.*;

import javax.servlet.*;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.hanqi.dao.User;
import com.hanqi.dao.UserDal;

/**
 * Servlet implementation class FindUserList
 */
public class FindUserList extends HttpServlet {
    private static final long serialVersionUID = 1L;

    /**
     * @see HttpServlet#HttpServlet()
     */
    public FindUserList() {
        super();
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        //
        request.setCharacterEncoding("UTF-8");
        response.setContentType("text/html;charset=UTF-8");
        response.setCharacterEncoding("UTF-8");
                        UserDal ud = new UserDal();
                        try
                        {
                        ArrayList<User> al = ud.getListAll();
                        request.setAttribute("userlist", al);
                        }
                        catch(Exception e)
                        {
                            response.getWriter().append("查找数据失败");
                            e.printStackTrace();
                        }

        //页面跳转
        request.getRequestDispatcher("ShowUserList.jsp").forward(request,response);

    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        doGet(request, response);
    }

}

查找

package com.hanqi.dao;

import java.sql.*;
import java.util.ArrayList;

import com.hanqi.common.*;

//关于User表的数据库操作类
public class UserDal
{

    //增
    public int insert(User user) throws Exception
    {
        int rtn = -1;

        Connection conn = DBHelper.getConnection();

        PreparedStatement pst = null;

        if (conn != null)
        {
            try{
            String sql = "insert into T_User (user_id, user_name, password,user_time) values (?,?,?,?) ";

            pst = conn.prepareStatement(sql);

            pst.setString(1, user.getUserid());
            pst.setString(2, user.getUsername());
            pst.setString(3, user.getPassword());
            pst.setString(4, user.getuserTime());
            rtn = pst.executeUpdate();
        }
            catch(Exception ex)
            {
                throw ex;
            }
            finally
            {
            try
            {
                pst.close();
            }
            catch(Exception e)
            {
                conn.close();
            }
            }
        }

        return rtn;
    }

    //删

    public int delete(String user_id) throws Exception
    {
        int rtn = -1;

        Connection conn = DBHelper.getConnection();

        PreparedStatement pst = null;

        if (conn != null)
        {
            try{
            String sql = "delete T_User where user_id = ?";

            pst = conn.prepareStatement(sql);

            pst.setString(1, user_id);

            rtn = pst.executeUpdate();
            }
            catch(Exception ex)
            {
                throw ex;
            }
            finally
            {
            try
            {
                pst.close();
            }
            catch(Exception e)
            {
                conn.close();
            }
            }
        }

        return rtn;
    }

    //改
    public int update(User user) throws Exception
    {
    int rtn = -1;

    Connection conn = DBHelper.getConnection();

    PreparedStatement pst = null;

    if (conn != null)
    {
        try
        {
        String sql = "update T_User set user_name = ?,password = ? "
                + "where user_id = ? ";

        pst = conn.prepareStatement(sql);

        pst.setString(3, user.getUserid());
        pst.setString(1, user.getUsername());
        pst.setString(2, user.getPassword());

        rtn = pst.executeUpdate();
    }
        catch(Exception ex)
        {
            throw ex;
        }
        finally
        {
        try
        {
            pst.close();
        }
        catch(Exception e)
        {
            conn.close();
        }
        }
    }

    return rtn;
}

    //查
    public ArrayList<User> getListAll() throws Exception
    {
        ArrayList<User> rtn = new ArrayList<User>();

        Connection conn = DBHelper.getConnection();

        PreparedStatement pst = null;

        if (conn != null)
        {
            try
            {

            String sql = "select * from t_user";

            pst = conn.prepareStatement(sql);

            ResultSet rs = pst.executeQuery();
            if(rs != null)
            {
                while(rs.next())
                {
                    User u = new User();

                    u.setUserid(rs.getString("user_id"));
                    u.setUsername(rs.getString("user_name"));
                    u.setPassword(rs.getString("password"));
                    u.setuserTime(rs.getString("user_time"));
                    rtn.add(u);        //取一个数就放一个数
                }
            }
            }
            catch(Exception ex)
            {
                throw ex;
            }
            finally
            {
            try
            {
                pst.close();
            }
            catch(Exception e)
            {
                conn.close();
            }
            }
        }
        return rtn;
    }
}

M