基于servlet和jsp的简单注册登录页面(包括：增删查改及分页显示)

一共建了8个包：分别是com.etc.biz,

　　　　　　　　　　 com.etc.dao,

 　　　　　　　　　　com.etc.dao.impl,

　　　　　　　　　　 com.etc.entity,

　　　　　　　　　　 com.etc.rowmapping,

　　　　　　　　　　 com.etc.servlet,

　　　　　　　　　　 com.etc.svc,

　　　　　　　　　　 com.etc.tools

package com.etc.biz;

import java.sql.SQLException;
import java.util.List;
import com.etc.dao.UserDaoI;
import com.etc.dao.impl.UserDaoImpl;
import com.etc.entity.Page;
import com.etc.entity.User;


public class UserBiz {

    UserDaoI udi = new UserDaoImpl();
    public boolean save(User user) throws SQLException
    {
        User u = udi.getUserByUname(user.getUsername());
        if(u!=null)
            throw new RuntimeException("用户已存在");
        int re = udi.insert(user);
        return re>0?true:false;
    }
    
    public boolean login(String username, String password) throws SQLException
    {
        User u = udi.getUserByUname(username);
        if(u==null)
        {
            throw new RuntimeException("该用户名不存在");
        }
        else
        {
            if(udi.login(username, password)!=null)
            {
                return true;
            }
            else
            {
                throw new RuntimeException("密码错误");
            }
            
        }
    }
    
    public boolean delUser(String username,String password) throws SQLException{
        User u = udi.getUserByUname(username);
        if(!u.getPassword().equals(password))
            throw new RuntimeException("无法删除他人信息");
        udi.remove(username);
        return true;
    }
    
    public boolean updUser(User user) throws SQLException{
        int i = udi.update(user);
        if(i>0)
            return true;
        throw new RuntimeException("无法修改他人信息");
        
    }
    
    public boolean modpwd(String username,String opwd,String npwd) throws SQLException{
        User temp = udi.getUserByUname(username);
        if(temp==null)
            throw new RuntimeException("该用户不存在");
        if(!opwd.equals(temp.getPassword()))
            throw new RuntimeException("用户密码错误");
        temp.setPassword(npwd);
        int i = udi.update(temp);
        return i>0?true:false;
    }
    
    public List<User> getAllUser(Page page) throws SQLException{ 
        return udi.getAllUser(page);
    }

    public List<User> getUser(String username,Page page) throws SQLException{
        return udi.getUserBy(username,page);
    }
    
    public int getCount() throws SQLException
    {
        int i = udi.getCountOfUser();
        if(i>0)
            return i;
        throw new RuntimeException("表中无数据");
    }
    
    public int queryCount(String username) throws SQLException
    {
        int i = udi.queryCountOfUser(username);
        if(i>0)
            return i;
        throw new RuntimeException("表中无数据");
    }
}

package com.etc.dao;

import java.sql.SQLException;
import java.util.List;

import com.etc.entity.Page;
import com.etc.entity.User;

public interface UserDaoI {

    public int insert(User user) throws SQLException;
    
    public int update(User user) throws SQLException;
    
    public void remove(String username) throws SQLException;
    
    public List<User> getAllUser(Page page) throws SQLException;
    
    public List<User> getUserBy(String username,Page page) throws SQLException;
    
    public User getUserByUname(String uname) throws SQLException;
    
    public User login(String username, String password) throws SQLException;
    
    public int getCountOfUser() throws SQLException;
    
    public int queryCountOfUser(String username) throws SQLException;
}

package com.etc.dao.impl;

import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import com.etc.dao.UserDaoI;
import com.etc.entity.Page;
import com.etc.entity.User;
import com.etc.rowmapping.UserMapping;
import com.etc.tools.MyDBConnection;

public class UserDaoImpl implements UserDaoI{

    public int insert(User user) throws SQLException
    {
        String sql = "insert into user" +
            "(username,password,name,sex,major,college,phone)values"
            + "('"+user.getUsername()
            + "','"+user.getPassword()
            + "','"+user.getName()
            + "','"+user.getSex()
            + "','"+user.getMajor()
            + "','"+user.getCollege()
            + "','"+user.getPhone()+"')";
        return MyDBConnection.ExecSQL(sql);    

    }
    
    public int update(User user) throws SQLException
    {
        int i = 0;
        String sql = "update user set name=?,sex=?,major=?,college=?,phone=? where username=? and password=?";
        PreparedStatement pstmt = MyDBConnection.getPrepareStatement(sql);
        pstmt.setString(1, user.getName());
        pstmt.setString(2, user.getSex());
        pstmt.setString(3, user.getMajor());
        pstmt.setString(4, user.getCollege());
        pstmt.setString(5, user.getPhone());
        pstmt.setString(6, user.getUsername());
        pstmt.setString(7, user.getPassword());
        i = pstmt.executeUpdate();
        return i;
    }
    
    public void remove(String username) throws SQLException
    {
        String sql = "delete from user where username=?";
        PreparedStatement pstmt = MyDBConnection.getPrepareStatement(sql);
        pstmt.setString(1, username);
        pstmt.executeUpdate();
        
//        String sql = "delete from user where username="+username;
//        int resulte = MyDBConnection.ExecSQL(sql);
    }
    
    public List<User> getAllUser(Page page) throws SQLException//传入一个page参数
    {
        //String sql ="select * from user limit "+0+","+2;   limit page.getfirstrow(),page.getRecordofpage()
        String sql ="select * from user limit "+ page.getFirstrow()+","+page.getRecordofpage();
        ResultSet rs = MyDBConnection.ExecQuery(sql);
        List<User> users = new ArrayList<User>();
        while(rs.next()){
            users.add(UserMapping.getUser(rs));
        }
        return users;
    }
    
    public List<User> getUserBy(String username,Page page) throws SQLException
    {
        String sql ="select * from user where username like"+"'%"+username+"%'" + "limit " + page.getFirstrow()+","+page.getRecordofpage();
        ResultSet rs = MyDBConnection.ExecQuery(sql);
        List<User> users = new ArrayList<User>();
        while(rs.next()){
            users.add(UserMapping.getUser(rs));
        }
        return users;
    }
    
    public User getUserByUname(String uname) throws SQLException
    {
        String sql ="select * from user where username=?";
        PreparedStatement pstmt=  MyDBConnection.getPrepareStatement(sql);
        pstmt.setString(1, uname);
        ResultSet rs = pstmt.executeQuery();
        User user = null;
        if(rs.next()){
            user = UserMapping.getUser(rs);
        }
        return user;
    }
    
    public User login(String username, String password) throws SQLException
    {
        
        String sql = "select * from user where username=? and password=?";
        PreparedStatement pstmt = MyDBConnection.getPrepareStatement(sql);
        pstmt.setString(1, username);
        pstmt.setString(2, password);
        ResultSet rs = pstmt.executeQuery();
        User user = null;
        if(rs.next())
        {
            user = UserMapping.getUser(rs);
        }
        return user;
    }
    
    public int getCountOfUser() throws SQLException
    {
        String sql = "select count(*) num from user";
        PreparedStatement pstmt = MyDBConnection.getPrepareStatement(sql);
        ResultSet rs = pstmt.executeQuery();
        int user = 0;

        if(rs.next())
        {
            user = rs.getInt("num");

        }
        return user;
    }
    
    public int queryCountOfUser(String username) throws SQLException
    {
        String sql = "select count(*) num from user where username like"+"'%"+username+"%'";
        PreparedStatement pstmt = MyDBConnection.getPrepareStatement(sql);
        ResultSet rs = pstmt.executeQuery();
        int user = 0;

        if(rs.next())
        {
            user = rs.getInt("num");

        }
        return user;
    }
}

com.etc.entity包下两个类：

package com.etc.entity;

public class Page {

    private int totalrecordcount;  //总条数select count(*) from user;
    private int recordofpage=5;//每页条数
    private int totalpage;//总页数
    private int currentpage;//当前页数  int page = 1;
                                    //try{
                                        //integet.parseint(request.getparameter("page"));
                                    //}catch()
                                    
    private int firstpage=1;//第一页 1
    private int previouspage;//上一页get(currentpage)-1
    private int nextpage;//下一页  get(currentpage)+1
    private int firstrow;//从第几条记录开始显示currentpage*recordofpage
    public int getTotalrecordcount() {
        return totalrecordcount;
    }
    public void setTotalrecordcount(int totalrecordcount) {
        this.totalrecordcount = totalrecordcount;
    }
    public int getRecordofpage() {
        return recordofpage;
    }
    public void setRecordofpage(int recordofpage) {
        this.recordofpage = recordofpage;
    }
    public int getTotalpage() {
        if(totalrecordcount%recordofpage==0)
            return totalrecordcount/recordofpage;
        else
            return totalrecordcount/recordofpage+1;
    }
    public void setTotalpage(int totalpage) {
        this.totalpage = totalpage;
    }
    public int getCurrentpage() {
        return currentpage;
    }
    public void setCurrentpage(int currentpage) {
        this.currentpage = currentpage;
    }
    public int getFirstpage() {
        return firstpage;
    }
    public void setFirstpage(int firstpage) {
        this.firstpage = firstpage;
    }
    public int getPreviouspage() {
        return previouspage;
    }
    public void setPreviouspage(int previouspage) {
        this.previouspage = previouspage;
    }
    public int getNextpage() {
        return nextpage;
    }
    public void setNextpage(int nextpage) {
        this.nextpage = nextpage;
    }
    public int getFirstrow() {
        return firstrow;
    }
    public void setFirstrow(int fitstrow) {
        this.firstrow = fitstrow;
    }
    public Page(int totalrecordcount, int recordofpage, int totalpage,
            int currentpage, int firstpage, int previouspage,
            int nextpage, int firstrow) {
        super();
        this.totalrecordcount = totalrecordcount;
        this.recordofpage = recordofpage;
        this.totalpage = totalpage;
        this.currentpage = currentpage;
        this.firstpage = firstpage;
        this.previouspage = previouspage;
        this.nextpage = nextpage;
        this.firstrow = firstrow;
    }
    
    
}

package com.etc.entity;


public class User {

    private int id;
    private String username;
    private String password;
    private String name;
    private String sex;
    private String major;
    private String college;
    private String phone;
    
//    private Collection<User> objs;//从数据库中读的集合
//    private int totalCount;//总的条数
//    private int pageNo;//当前的页数
//    private int pageCount;//每页的条数
    
    
    
    
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getSex() {
        return sex;
    }
    public void setSex(String sex) {
        this.sex = sex;
    }
    public String getMajor() {
        return major;
    }
    public void setMajor(String major) {
        this.major = major;
    }
    public String getCollege() {
        return college;
    }
    public void setCollege(String college) {
        this.college = college;
    }
    public String getPhone() {
        return phone;
    }
    public void setPhone(String phone) {
        this.phone = phone;
    }
    public User(int id, String username, String password, String name,
            String sex, String major, String college, String phone) {
        super();
        this.id = id;
        this.username = username;
        this.password = password;
        this.name = name;
        this.sex = sex;
        this.major = major;
        this.college = college;
        this.phone = phone;
    }
    public User(String username, String password, String name, String sex,
            String major, String college, String phone) {
        super();
        this.username = username;
        this.password = password;
        this.name = name;
        this.sex = sex;
        this.major = major;
        this.college = college;
        this.phone = phone;
    }
    
    public User(String password,String name, String sex, String major,
            String college, String phone) {
        super();
        this.password = password;
        this.name = name;
        this.sex = sex;
        this.major = major;
        this.college = college;
        this.phone = phone;
    }
    public User(String username, String password) {
        super();
        this.username = username;
        this.password = password;
    }
    public User() {
        super();
    }
    
    
    
    
    
    
    
}

package com.etc.rowmapping;

import java.sql.ResultSet;
import java.sql.SQLException;

import com.etc.entity.User;

public class UserMapping {

    public static User getUser(ResultSet rs)throws SQLException
    {
        User user = null;
        user = new User();
        user.setId(rs.getInt("id"));
        user.setUsername(rs.getString("username"));
        user.setPassword(rs.getString("password"));
        user.setName(rs.getString("name"));
        user.setSex(rs.getString("sex"));
        user.setMajor(rs.getString("major"));
        user.setCollege(rs.getString("college"));
        user.setPhone(rs.getString("phone"));
        return user;
    }
}

 com.etc.servlet包下有6个类：

package com.etc.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 javax.servlet.http.HttpSession;

import com.etc.svc.UserSvcImpl;

public class DeleteUserServlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        // TODO Auto-generated method stub
        //super.doGet(req, resp);
        doPost(req, resp);
    }
    
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        // TODO Auto-generated method stub
        //super.doPost(req, resp);
        String uname = req.getParameter("username");
        HttpSession session = req.getSession();
        String upwd = (String) session.getAttribute("password");
        UserSvcImpl usi = new UserSvcImpl();
        usi.DeleteUser(uname,upwd);
        resp.sendRedirect("viewAll");
    }
}

package com.etc.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 javax.servlet.http.HttpSession;

import com.etc.svc.UserSvcImpl;

public class LoginServlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        // TODO Auto-generated method stub
        //super.doGet(req, resp);
        doPost(req, resp);
    }
    
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        // TODO Auto-generated method stub
        //super.doPost(req, resp);
        String uname = req.getParameter("username");
        String upwd = req.getParameter("password");
        UserSvcImpl usi = new UserSvcImpl();
        usi.login(uname, upwd);
        HttpSession session = req.getSession();
        session.setAttribute("username",uname);
        session.setAttribute("password", upwd);
        req.getRequestDispatcher("admin/welcome.jsp").forward(req, resp);
    }
}

package com.etc.servlet;

import java.io.IOException;
import java.util.List;

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

import com.etc.entity.Page;
import com.etc.entity.User;
import com.etc.svc.UserSvcImpl;

public class QueryUserServlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        // TODO Auto-generated method stub
        //super.doGet(req, resp);
        doPost(req, resp);
    }
    
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        // TODO Auto-generated method stub
        //super.doPost(req, resp);
        String uname = req.getParameter("username");
        UserSvcImpl usi = new UserSvcImpl();
        
        int trc = usi.queryUserCount(uname);//记录总条数
        int ctp = 1;//当前页数
        try{
            ctp = Integer.parseInt((req.getParameter("currentpage")));
        }catch(NumberFormatException e){
            e.printStackTrace();
        }
        
        
        int rdop = 2;//每页条数
        int tp;//总页数，即最后一页数
        int fp = 1;//第一页
        int pp = ctp - 1;//上一页
        int np = ctp + 1;//下一页
        int fr = (ctp-1)*rdop; //从第几条记录开始显示
        if(trc%5==0)
            tp = trc / 5;
        else
            tp = trc / 5 + 1;
        Page page = new Page(trc, rdop, tp, ctp, fp, pp, np, fr);
        
        List<User> list = usi.QueryUser(uname,page);
        req.setAttribute("queryUser",list);
        page.setTotalrecordcount(usi.queryUserCount(uname));
        page.setCurrentpage(ctp);
        req.setAttribute("Page",page);
        req.setAttribute("name", uname);
        req.getRequestDispatcher("admin/queryUser.jsp").forward(req, resp);
    }
}

package com.etc.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.etc.entity.User;
import com.etc.svc.UserSvcImpl;

public class RegisterServlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        // TODO Auto-generated method stub
        //super.doGet(req, resp);
        doPost(req, resp);
    }
    
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        
        String uname = new String(req.getParameter("username").getBytes("ISO-8859-1"),"UTF-8");
        String upwd = new String(req.getParameter("password").getBytes("ISO-8859-1"),"UTF-8");
        String reupwd = new String(req.getParameter("repassword").getBytes("ISO-8859-1"),"UTF-8");
        String tname = new String(req.getParameter("name").getBytes("ISO-8859-1"),"UTF-8");
        String usex = new String(req.getParameter("sex").getBytes("ISO-8859-1"),"UTF-8");
        String umajor = new String(req.getParameter("major").getBytes("ISO-8859-1"),"UTF-8");
        String ucollege = new String(req.getParameter("college").getBytes("ISO-8859-1"),"UTF-8");
        String uphone = new String(req.getParameter("phone").getBytes("ISO-8859-1"),"UTF-8");
        
        if(upwd.equals(reupwd))
        {
            UserSvcImpl usi = new UserSvcImpl();
            User user = new User(uname, upwd, tname, usex, umajor, ucollege, uphone);
            usi.register(user);
            req.getRequestDispatcher("login.jsp").forward(req, resp);
        }
        else 
        {
            req.setAttribute("error", "密码不匹配");
            req.getRequestDispatcher("register.jsp").forward(req, resp);
        }
    }
}

package com.etc.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 javax.servlet.http.HttpSession;

import com.etc.entity.User;
import com.etc.svc.UserSvcImpl;

public class UpdateUserServlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        HttpSession session = req.getSession();
        String upwd = (String) session.getAttribute("password");
        String uname = new String(req.getParameter("username").getBytes("ISO-8859-1"),"UTF-8");
        String tname = new String(req.getParameter("name").getBytes("ISO-8859-1"),"UTF-8");
        String usex = new String(req.getParameter("sex").getBytes("ISO-8859-1"),"UTF-8");
        String umajor = new String(req.getParameter("major").getBytes("ISO-8859-1"),"UTF-8");
        String ucollege = new String(req.getParameter("college").getBytes("ISO-8859-1"),"UTF-8");
        String uphone = new String(req.getParameter("phone").getBytes("ISO-8859-1"),"UTF-8");
        
        UserSvcImpl usi = new UserSvcImpl();
        User user = new User(uname,upwd,tname, usex, umajor, ucollege, uphone);
        usi.UpdateUser(user);
        resp.sendRedirect("viewAll");
    }
    
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        
        doGet(req, resp);
    }
}

package com.etc.servlet;

import java.io.IOException;
import java.util.List;

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

import com.etc.entity.Page;
import com.etc.entity.User;
import com.etc.svc.UserSvcImpl;

public class ViewAllServlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        // TODO Auto-generated method stub
        //super.doGet(req, resp);
        doPost(req, resp);
    }
    
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        // TODO Auto-generated method stub
        //super.doPost(req, resp);
        //调用业务逻辑
        UserSvcImpl usi = new UserSvcImpl();
        int trc = usi.getUserCount();//记录总条数
        int ctp = 1;//当前页数
        try{
            ctp = Integer.parseInt((req.getParameter("currentpage")));
        }catch(NumberFormatException e){
            e.printStackTrace();
        }
        
        
        int rdop = 5;//每页条数
        int tp;//总页数
        int fp = 1;//第一页
        int pp = ctp - 1;//上一页
        int np = ctp + 1;//下一页
        int fr = (ctp-1)*rdop; //从第几条记录开始显示
        if(trc%5==0)
            tp = trc / 5;
        else
            tp = trc / 5 + 1;
        Page page = new Page(trc, rdop, tp, ctp, fp, pp, np, fr);
        List<User> list = usi.getUserAll(page);
        //如何将list传递到allUser.jsp是关键问题
        //将返回值作为请求属性存储
        req.setAttribute("allUser",list);
        page.setTotalrecordcount(usi.getUserCount());
        page.setCurrentpage(ctp);
        req.setAttribute("Page",page);
        //跳转
        req.getRequestDispatcher("admin/allUser.jsp").forward(req, resp);
    }
}

com.etc.svc包下有两个类：

package com.etc.svc;


import java.util.List;

import com.etc.entity.Page;
import com.etc.entity.User;

public interface UserSvcI {

    //public void SaveUser(User user);
    
    
    public boolean register(User user);
    
    public boolean login(String username,String password);
    
    public List<User> getUserAll(Page page);
    
    public boolean DeleteUser(String username,String password);
    
    public List<User> QueryUser(String username,Page page);
    
    public boolean UpdateUser(User user);
    
    
}

package com.etc.svc;

import java.sql.Connection;
import java.sql.SQLException;
import java.util.List;

import com.etc.biz.UserBiz;
import com.etc.entity.Page;
import com.etc.entity.User;
import com.etc.tools.MyDBConnection;

public class UserSvcImpl implements UserSvcI{
//增删改的操作需要对事务进行操作，查不需要
    UserBiz ub = new UserBiz();
    Connection conn = MyDBConnection.getConnection();
    public boolean DeleteUser(String username,String password)
    {
        
        try {
            conn.setAutoCommit(false);
            ub.delUser(username,password);
            conn.commit();
            return true;
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            try {
                conn.rollback();
            } catch (SQLException e1) {
                // TODO Auto-generated catch block
                e1.printStackTrace();
            }
        }
        return false;
    }
    
    public boolean login(String username, String password){
        // TODO Auto-generated method stub

            try {
                if(ub.login(username, password))
                    return true;
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            return false;
    }
    
    public boolean register(User user) {
        // TODO Auto-generated method stub
        try {
            conn.setAutoCommit(false);
            ub.save(user);
            conn.commit();
            return true;
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            try {
                conn.rollback();
            } catch (SQLException e1) {
                // TODO Auto-generated catch block
                e1.printStackTrace();
            }
            e.printStackTrace();
        }
        return false;
    }
    
    public boolean UpdateUser(User user){
        try {
            conn.setAutoCommit(false);
            ub.updUser(user);
            conn.commit();
            return true;
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            try {
                conn.rollback();
            } catch (SQLException e1) {
                // TODO Auto-generated catch block
                e1.printStackTrace();
            }
            e.printStackTrace();
        }
        return false;
    }
    
    public List<User> getUserAll(Page page)//传参
    {
        try {
            return ub.getAllUser(page);//传参
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return null;
    }
    
    public List<User> QueryUser(String username,Page page)
    {
        try {
            return ub.getUser(username,page);
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return null;
        
    }
    
    public int getUserCount()
    {
        try {
            return ub.getCount();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return 0;
    }
    
    public int queryUserCount(String username)
    {
        try {
            return ub.queryCount(username);
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return 0;
    }
}

package com.etc.tools;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class MyDBConnection {

    public static Connection conn = null;
    public static Connection getConnection()
    {
        if(conn !=null)
            return conn;
        
        try {
            Class.forName("com.mysql.jdbc.Driver");
            conn = DriverManager.getConnection(
                    "jdbc:mysql://localhost:3306/kaijie?useUnicode=true&characterEncoding=utf8", "root", "123");
            
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return conn;
    }
    
    public static Statement getStatement(){
        if(conn==null)
            getConnection();
        try {
            return conn.createStatement();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return null;
    }
    
    public static PreparedStatement getPrepareStatement(String sql){
        if(conn==null)
            getConnection();
        try {
            return conn.prepareStatement(sql);
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return null;
    }

    public static ResultSet ExecQuery(String sql){
        if(conn==null)
            getConnection();
        Statement stmt;
        try {
            stmt = conn.createStatement();
            ResultSet rs = stmt.executeQuery(sql);
            return rs;
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return null;
    }
    
    public static int ExecSQL(String sql){
        if(conn==null)
            getConnection();
        Statement stmt;
        try {
            stmt = conn.createStatement();
            int result = stmt.executeUpdate(sql);
            return result;
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return 0;
    }
}