UserBeanCL .jsppackage com.jinlinger.model;
import java.sql.*;
import java.util.*;
public class UserBeanCL {
private Statement sm=null;
private ResultSet rs=null;
private Connection ct=null;
private int pageSize=3;
private int rowCount=0;//该值从数据库查询出的
int pageCount=0; //该值是通过pageCount和rowCount计算来
//返回分页的总页数
public int getPageCount(){
//int pageCount=0; //该值是通过pageCount和rowCount计算来
//....
try {
//得到连接
ct=new ConnDB().getConn();
//4、查询
rs=sm.executeQuery("select count(*) from users ");
if(rs.next()){
rowCount=rs.getInt(1);
}
//计算 pageCount
if(rowCount%pageSize==0){
pageCount =rowCount/pageSize;
}else{
pageCount=rowCount/pageSize+1;
}
//计算pageCount
} catch (Exception e) {
e.printStackTrace();
// handle exception
}finally{
//关闭资源
this.close();
}
return pageCount;
} //分页
public ArrayList getUsersByPage(int pageNow){
ArrayList al=new ArrayList();
try {
//得到连接
ct=new ConnDB().getConn();
//3、创建 statment
sm=ct.createStatement();
//4、查询
// rs=sm.executeQuery("select count(*) from users ");
//if(rs.next()){
//rowCount=rs.getInt(1);
// }
//计算 pageCount
//if(rowCount%pageSize==0){
//pageCount =rowCount/pageSize;
// }else{
//pageCount=rowCount/pageSize+1;
//}
//查询分页
rs=sm.executeQuery("select top "+pageSize+" * from users where UserId not in(select top "+pageSize*(pageNow-1)+" UserId from users)");
//开始将rs封装到ArrayList
while(rs.next()){
UserBean ub=new UserBean();
ub.setUserId(rs.getInt(1));
ub.setUsernameString(rs.getString(2));
ub.setPasswd(rs.getString(3));
ub.setEmail(rs.getString(4));
ub.setGrade(rs.getInt(5));
//将UB放入到ArrayList
al.add(ub);
}
} catch (Exception e) {
e.printStackTrace();
}finally{
this.close();
}
return al;
}
//关闭资源
public void close(){
try {
if(rs!=null){
rs.close();
rs=null;
}
if(sm!=null){
sm.close();
}
if(ct!=null){
ct.close();
}
} catch (Exception e2) {
e2.printStackTrace();
}
}
//验证用户是否存在
public boolean checkUser(String u,String p){ boolean b=false;
try {
//到数据库中验证用户
ct=new ConnDB().getConn();
//创建Statement
sm=ct.createStatement();
//查询
rs=sm.executeQuery("select top 1 passwd from users where username='"+u+"'");
//验证
if(rs.next()){
//用户名合法
if(rs.getString(1).equals(p))
{
b=true;
}
}
} catch (Exception e) {
e.printStackTrace();
}finally{
//函数!!
this.close();
}
return b;
}
}Wel.jsp
//上一页
if(pageNow!=1){
out.println("<a href=Welcome.jsp?pageNow="+(pageNow-1)+">上一页</a>");
}
//得到pageCount
int pageCount=ubc.getPageCount();
out.println(pageCount) //显示超链接
for(int i=1; i<=pageCount; i++){
out.println("<a href=Welcome.jsp?pageNow="+i+">["+i+"]</a>");
}
//下一页
if(pageNow!=pageCount){
out.println("<a href=Welcome.jsp?pageNow="+(pageNow+1)+">下一页</a>");
}
结果是:pageCount=0,给位帮帮忙,本人初学,菜鸟
import java.sql.*;
import java.util.*;
public class UserBeanCL {
private Statement sm=null;
private ResultSet rs=null;
private Connection ct=null;
private int pageSize=3;
private int rowCount=0;//该值从数据库查询出的
int pageCount=0; //该值是通过pageCount和rowCount计算来
//返回分页的总页数
public int getPageCount(){
//int pageCount=0; //该值是通过pageCount和rowCount计算来
//....
try {
//得到连接
ct=new ConnDB().getConn();
//4、查询
rs=sm.executeQuery("select count(*) from users ");
if(rs.next()){
rowCount=rs.getInt(1);
}
//计算 pageCount
if(rowCount%pageSize==0){
pageCount =rowCount/pageSize;
}else{
pageCount=rowCount/pageSize+1;
}
//计算pageCount
} catch (Exception e) {
e.printStackTrace();
// handle exception
}finally{
//关闭资源
this.close();
}
return pageCount;
} //分页
public ArrayList getUsersByPage(int pageNow){
ArrayList al=new ArrayList();
try {
//得到连接
ct=new ConnDB().getConn();
//3、创建 statment
sm=ct.createStatement();
//4、查询
// rs=sm.executeQuery("select count(*) from users ");
//if(rs.next()){
//rowCount=rs.getInt(1);
// }
//计算 pageCount
//if(rowCount%pageSize==0){
//pageCount =rowCount/pageSize;
// }else{
//pageCount=rowCount/pageSize+1;
//}
//查询分页
rs=sm.executeQuery("select top "+pageSize+" * from users where UserId not in(select top "+pageSize*(pageNow-1)+" UserId from users)");
//开始将rs封装到ArrayList
while(rs.next()){
UserBean ub=new UserBean();
ub.setUserId(rs.getInt(1));
ub.setUsernameString(rs.getString(2));
ub.setPasswd(rs.getString(3));
ub.setEmail(rs.getString(4));
ub.setGrade(rs.getInt(5));
//将UB放入到ArrayList
al.add(ub);
}
} catch (Exception e) {
e.printStackTrace();
}finally{
this.close();
}
return al;
}
//关闭资源
public void close(){
try {
if(rs!=null){
rs.close();
rs=null;
}
if(sm!=null){
sm.close();
}
if(ct!=null){
ct.close();
}
} catch (Exception e2) {
e2.printStackTrace();
}
}
//验证用户是否存在
public boolean checkUser(String u,String p){ boolean b=false;
try {
//到数据库中验证用户
ct=new ConnDB().getConn();
//创建Statement
sm=ct.createStatement();
//查询
rs=sm.executeQuery("select top 1 passwd from users where username='"+u+"'");
//验证
if(rs.next()){
//用户名合法
if(rs.getString(1).equals(p))
{
b=true;
}
}
} catch (Exception e) {
e.printStackTrace();
}finally{
//函数!!
this.close();
}
return b;
}
}Wel.jsp
//上一页
if(pageNow!=1){
out.println("<a href=Welcome.jsp?pageNow="+(pageNow-1)+">上一页</a>");
}
//得到pageCount
int pageCount=ubc.getPageCount();
out.println(pageCount) //显示超链接
for(int i=1; i<=pageCount; i++){
out.println("<a href=Welcome.jsp?pageNow="+i+">["+i+"]</a>");
}
//下一页
if(pageNow!=pageCount){
out.println("<a href=Welcome.jsp?pageNow="+(pageNow+1)+">下一页</a>");
}
结果是:pageCount=0,给位帮帮忙,本人初学,菜鸟
解决方案 »
- Java 程序连接数据库 需要手工输入两个参数 并插入到对应的表上去 程序如下但是报空指针 高手指点下
- 用struts2 ajax标签出现了一个问题
- 一个jsp页面显示出两张表的内容
- [java基础,很紧急,大家帮忙解决一下。]
- struts1.1的问题
- SSH刷新之后出现 org.hibernate.exception.GenericJDBCException: could not inspect JDBC autocommit mode
- XMPP协议的问题 高分求助
- hibernate3 + mysql5.0的问题
- 初学ejb,简单问题,在线等待
- 帮我看看这个布署是错误什么原因啊!急!!! (LINUX+WEBLOG8.1sp2)
- jdk1.5/1.6+hibernate + c3p0+ ojdbc+oracle 如何清除statemate cache
- 迷茫、求助
public int getPageCount()
传回真实的总页数应该怎么写?