jsp分页技术（1）

package com.sp.model;
import java.sql.*;
import java.util.*;
public class UserbeanCl {

//业务逻辑 
private Connection ct=null;
private PreparedStatement ps=null;
private ResultSet rs=null;
private int pageCount=0;//共有几页(计算)


//分页显示

//修改用户
public  boolean update(String s1,String s2,String s3,String s4,String s5,String s6,String s7,String s8,String s9){
boolean b=false;

// private longuserId ;
//  private  String username ;
//  private  String truename ;
//  private  String passwd ;
//  private  String email ;
//  private  String phone ;
//  private  String address ;
//  private  String postcode ;
//  private int grade ;
//
try{
ConnDB  cd=new ConnDB();
ct=cd.getCon();
 ps=ct.prepareStatement("update  users set  username='"+s2+"'  , passwd='"+s3+"', email='"+s4+"', grade="+s5+"', truename="+s6+"', phone="+s7+"', address="+s8+"', postcode="+s9+" where userId='"+s1+"'");
int num= ps.executeUpdate();
if(num==1){
b=true;

}
 
}catch(Exception e){
e.printStackTrace();
}finally{
   
    this.close();
   }

return  b;

}
//增加用户信息,
//增加用户放在注册用户上
// public  boolean addUser(String s2,String s3,String s4,String s5){
// boolean b=false;
// try{
// ConnDB  cd=new ConnDB();
// ct=cd.getCon();
//  ps=ct.prepareStatement("insert into  users values(?,?,?,?)");
//  
//  ps.setString(1, s2);
//  ps.setString(2, s3);
//  ps.setString(3, s4);
//  ps.setString(4, s5);
// // ps.setString(5, s5);
// int num= ps.executeUpdate();
// if(num==1){
// b=true;
//
// }
//  
// }catch(Exception e){
// e.printStackTrace();
// }finally{
//    
//     this.close();
//    }
//
// return  b;
//
// }
//
//查询用户
public ArrayList getResultUser(String userId,String username){

ArrayList al=new ArrayList();

try {


ConnDB cd=new ConnDB();
ct=cd.getCon();
if(!userId.equals("")&&username.equals("")){

ps=ct.prepareStatement("select * from users where userId='"+userId+"'");
System.out.println("ID号查询");
}
          if(userId.equals("")&&!username.equals("")){
         
ps=ct.prepareStatement("select * from users where username='"+username+"'");

 System.out.println("通过用户名查询");
          }

           if(!userId.equals("")&&!username.equals("")){
            System.out.println("userId="+userId);
            ps=ct.prepareStatement("select * from users where userId='"+userId+"' and  username='"+username+"'");
           System.out.println("通过用户名和ID号查询");
           
           }
rs=ps.executeQuery();

while(rs.next()){

//将rs中的 每条记录封装到UserBean ub
UserBean ub=new  UserBean();
ub.setUserId(rs.getInt(1));
ub.setUsername(rs.getString(2));
ub.setPasswd(rs.getString(3));
ub.setEmail(rs.getString(4));
ub.setGrade(rs.getInt(5));

//将ub ,放入到ArrayList 中
al.add(ub);

}
   }
   catch (Exception ex) {
   
    ex.printStackTrace();
   }finally{
   
    this.close();
   }
   
   return al;


}

//删除用户
public  boolean deluser(String userid){
boolean b=false;
try{
ConnDB  cd=new ConnDB();
     ct=cd.getCon();
 ps=ct.prepareStatement("delete users where userId="+userid+"");
int num= ps.executeUpdate();
if(num==1){
b=true;

}
 
}catch(Exception e){
e.printStackTrace();
}finally{
   
    this.close();
   }

return  b;

}
public ArrayList getResultByPage(int pageNow,int pageSize){

ArrayList al=new ArrayList();

try {


int rowCount=0;//共有几条记录(查表)


//得到rowCount
ConnDB cd=new ConnDB();
ct=cd.getCon();

ps=ct.prepareStatement("select count(*) from users");

rs=ps.executeQuery();

if(rs.next()){

rowCount=rs.getInt(1);
}

//计算pageCount
if(rowCount%pageSize==0){

pageCount=rowCount/pageSize;
}else{
pageCount=rowCount/pageSize+1;
}

ps=ct.prepareStatement("select top "+pageSize+" * from users where userId not in (select top "+pageSize*(pageNow-1)+" userId from users)");


rs=ps.executeQuery();

while(rs.next()){

//将rs中的 每条记录封装到UserBean ub
UserBean ub=new UserBean();
ub.setUserId(rs.getInt(1));
ub.setUsername(rs.getString(2));
ub.setPasswd(rs.getString(3));
ub.setEmail(rs.getString(4));
ub.setGrade(rs.getInt(5));

//将ub ,放入到ArrayList 中
al.add(ub);



System.out.println("ub="+ub);
}
   }
   catch (Exception ex) {
   
    ex.printStackTrace();
   }finally{
   
    this.close();
   }
   
   return al;


}
public int getPageCount(){
return this.pageCount;
}
//验证用户
public boolean checkUser(String u,String p){
   boolean b=false;

try{
ConnDB cd=new ConnDB();
ct=cd.getCon();
ps=ct.prepareStatement("select top 1 passwd from users  where username=?");
ps.setString(1,u);
rs=ps.executeQuery();
if(rs.next()){
String dbpass=rs.getString(1);
if(p.equals(dbpass)){

b=true;
}

}


}catch(Exception e){

e.printStackTrace();
}finally {


this.close();
}
return b;

}

//关闭资源
public void close(){

try {

if(rs!=null){
rs.close();
rs=null;
}
if(ps!=null){
ps.close();
ps=null;
}
if(ct!=null){
ct.close();
ct=null;
}
   }
   catch (Exception ex) {
   
    ex.printStackTrace();
   }
}
}