Java分页代码的实现

在项目中，分页是一个项目中必不可少的，它可以防止我们从数据库中进行大量数据查询时速度变慢，提高我们的查询效率

1、定义分页模型：PageModel

    package com.common.page;                import java.util.List;                /**        * 封装分页信息        * @author Administrator        *        */        public class PageModel<E> {                    //结果集            private List<E> list;                        //查询记录数            private int totalRecords;                        //每页多少条数据            private int pageSize;                        //第几页            private int pageNo;                        /**            * 总页数            * @return            */            public int getTotalPages() {                return (totalRecords + pageSize - 1) / pageSize;            }                        /**            * 取得首页            * @return            */            public int getTopPageNo() {                return 1;            }                        /**            * 上一页            * @return            */            public int getPreviousPageNo() {                if (pageNo <= 1) {                    return 1;                }                return pageNo - 1;            }                        /**            * 下一页            * @return            */            public int getNextPageNo() {                if (pageNo >= getBottomPageNo()) {                    return getBottomPageNo();                }                return pageNo + 1;              }                        /**            * 取得尾页            * @return            */            public int getBottomPageNo() {                return getTotalPages();            }                        public List<E> getList() {                return list;            }                    public void setList(List<E> list) {                this.list = list;            }                    public int getTotalRecords() {                return totalRecords;            }                    public void setTotalRecords(int totalRecords) {                this.totalRecords = totalRecords;            }                    public int getPageSize() {                return pageSize;            }                    public void setPageSize(int pageSize) {                this.pageSize = pageSize;            }                    public int getPageNo() {                return pageNo;            }                    public void setPageNo(int pageNo) {                this.pageNo = pageNo;            }        }  

2、分页测试：在MySQL中建立admin表，里面有字段id、name、password

3、简历Admin的实体bean类：

    package com.common.page;                public class Admin {            private int id;            private String name;            private String password;            public int getId() {                return id;            }            public void setId(int id) {                this.id = id;            }            public String getName() {                return name;            }            public void setName(String name) {                this.name = name;            }            public String getPassword() {                return password;            }            public void setPassword(String password) {                this.password = password;            }                }  

4、测试调用：

    package com.common.page;                import java.sql.Connection;        import java.sql.PreparedStatement;        import java.sql.ResultSet;        import java.sql.SQLException;        import java.util.ArrayList;        import java.util.List;                import com.common.db.DbUtil;                public class Client {            public static PageModel findAdmins(int pageNo,int pageSize){                Connection conn=DbUtil.getConnection();                String sql="select * from admin limit ?,?";                PageModel pageModel=null;                PreparedStatement pstm=null;                ResultSet rs=null;                Admin admin=null;                List<Admin> list=new ArrayList<Admin>();                try {                    pstm=conn.prepareStatement(sql);                    pstm.setInt(1, (pageNo-1)*pageSize);                    pstm.setInt(2, pageNo*pageSize);                    rs=pstm.executeQuery();;                    while(rs.next()){                        admin=new Admin();                        admin.setId(rs.getInt("a_id"));                        admin.setName(rs.getString("a_name"));                        admin.setPassword(rs.getString("a_pwd"));                        list.add(admin);                    }                    ResultSet rs2=pstm.executeQuery("select count(*) from admin");                    int total=0;                    if(rs2.next()){                        total=rs2.getInt(1);                    }                    pageModel=new PageModel();                    pageModel.setPageNo(pageNo);                    pageModel.setPageSize(pageSize);                    pageModel.setTotalRecords(total);                    pageModel.setList(list);                } catch (SQLException e) {                    e.printStackTrace();                }finally{                    DbUtil.close(conn);                    DbUtil.close(pstm);                    DbUtil.close(rs);                }                return pageModel;            }                        public static void main(String[] args) {                PageModel pageModel=Client.findAdmins(2,4);                List<Admin> list=pageModel.getList();                for(Admin a:list){                    System.out.print("ID:"+a.getId()+",用户名:"+a.getName()+",密码:"+a.getPassword());                    System.out.println();                }                System.out.print("当前页:"+pageModel.getPageNo()+" ");                System.out.print("共"+pageModel.getTotalPages()+"页  ");                System.out.print("首页:"+pageModel.getTopPageNo()+" ");                System.out.print("上一页:"+pageModel.getPreviousPageNo()+" ");                System.out.print("下一页:"+pageModel.getNextPageNo()+" ");                System.out.print("尾页:"+pageModel.getBottomPageNo()+" ");                System.out.print("共"+pageModel.getTotalRecords()+"条记录");                System.out.println();            }                }  

这样分页效果就实现了，我们要实现分页效果，只要传入相应的参数和相应的数据库执行语句即可实现，希望大家能灵活运用。

转自：http://blog.csdn.net/harderxin/article/details/7731313