Java's implementation of paging

about Java implementation paging

Transferred from: http://www.cnblogs.com/slliang/archive/2012/08/22/2651053.html

1. Paging tool class, encapsulating paging information

Package Com.student.util;import java.util.list;import com.student.entity.person;/** * Packaging Paging information * @author Administrator * *        @param <Person> */public class Pagemodel<e> {//result set private list<e> List;        Query record number private int totalrecords;        The first few pages of private int pageno;        How many records per page private int pageSize;    Total pages public int gettotalpages () {return (totalrecords + pageSize-1)/pagesize;    }//Home public int gettoppage () {return 1;        }//prev public int getpreviouspage () {if (pageno<=1) {return 1;    } return pageNo-1;        }//Next public int getnextpage () {if (Pageno>=getbottompage ()) {return getbottompage ();    } return pageno+1;    }//Last public int getbottompage () {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 Getpageno () {return pageno;    } public void Setpageno (int pageno) {This.pageno = PageNo;    } public int getpagesize () {return pageSize;    } public void SetPageSize (int pageSize) {this.pagesize = pageSize; }}

　　2. Test class

 Public classpagemodeltest{ Public Static voidMain (string[] args) {intPageno=1; intpagesize=10;    Finduserlist (pageno,pagesize); }    /*** Paging Query *@paramPageNo Page *@parampageSize number of records per page *@returnpagemodel<e>*/     PublicPagemodel<person> Finduserlist (intPageNo,intpageSize) {Pagemodel<Person> Pagemodel =NULL; Connection Conn=NULL; PreparedStatement PS=NULL; ResultSet RS=NULL; //the paging statements for each database are not the same                /*Oracle Implementation paging, three-tier nesting, where 10 should be pageno*pagesize, 0 is (pageNo-1) *pagesize String sql= "Select Column1,column2,column 3,column4,column5 from (select RowNum rn,column1,column2,column3,column4,column5 from (sel         ECT COLUMN1,COLUMN2,COLUMN3,COLUMN4,COLUMN5 from table_name ORDER BY column DESC) where rownum<=10)        where rn>0 "; */        //MySQL Implementation pagingString sql= "SELECT * from the person ORDER by id DESC limit?,? "; Conn=dbutil.getutil (). getconnection (); Try{PS=conn.preparestatement (SQL); Ps.setint (1, (pageNo-1) *pageSize); Ps.setint (2, pageSize); RS=Ps.executequery (); List<Person> personlist =NewArraylist<person>();  while(Rs.next ()) { person person=NewPerson (); Person.setname (Rs.getstring ("Stu_name")); Person.setpassword (Rs.getstring ("STU_PSW")); Person.setnumber (Rs.getstring ("Stu_number")); Person.setbirthday (Rs.getdate ("Stu_birth")); Person.setsex (Rs.getint ("Stu_sex")); Person.setpolity (Rs.getint ("Stu_polity")); Person.setbrief (Rs.getstring ("Stu_brief")); Person.settype (Rs.getint ("Type")); Person.setstate (Rs.getint ("State"));            Personlist.add (person); } Pagemodel=NewPagemodel<person>();            Pagemodel.setlist (personlist);            Pagemodel.settotalrecords (Gettotalrecords (conn));            Pagemodel.setpagesize (pageSize);        Pagemodel.setpageno (PageNo); } Catch(SQLException e) {//TODO auto-generated Catch blockE.printstacktrace (); }finally{            Try {                if(rs!=NULL) {rs.close (); }                if(ps!=NULL) {ps.close (); }                if(conn!=NULL) {conn.close (); }            } Catch(SQLException e) {//TODO auto-generated Catch blockE.printstacktrace (); }        }        returnPagemodel; }    /*** Get total record count, private method, external inaccessible, use in this class *@paramConn *@return     */    Private intGettotalrecords (Connection conn) {PreparedStatement PS=NULL; ResultSet RS=NULL; String SQL= "SELECT count (*) from person"; Conn=dbutil.getutil (). getconnection (); intCount=0; Try{PS=conn.preparestatement (SQL); RS=Ps.executequery ();  while(Rs.next ()) {//In this case, only one column is isolated from the SQL statement, otherwise it is not recommended to identify the field with intCount = Rs.getint (1); }        } Catch(SQLException e) {e.printstacktrace (); }finally{            Try {                if(rs!=NULL) {rs.close (); }                if(ps!=NULL) {ps.close (); }            } Catch(SQLException e) {//TODO auto-generated Catch blockE.printstacktrace (); }        }        returncount; }}

Java's implementation of paging