Paging (displaying information in a database to a Web page)

Problem Analysis:

　When we want to retrieve information from a database and display it on a Web page, if there is too much information in the database. On the one hand, the database overhead is very large, performance is reduced, on the other hand, displaying too much data on a single page can degrade the user experience.

Workaround:

1. Since the information displayed on each page after pagination is no longer just data aerial data, it is similar to the following:

So we need to create a page class:

 PackageCom.neuedu.manage.bean; Importjava.util.List;  Public classPage <T>{PrivateList<t> data;//data queried by the database   　　　　   Private intTotalrecord;//Total record count, database query       　　　　   Private intPageNumber;//Current page number   　　　　   Private intPageSize;//number of records per page        　　　　  PrivateString path;//the address of the JSP page link to jump to//private int index; //current index, calculated by//private int totalpage;//The total number of pages are calculated   
}

Where we create get and set methods for the first 5 variables, and because the last two variables are computed, only the Get method is created for them:

 Public intGetIndex () {/*** Current index value, calculated by*/     　　　　     return(Getpagenumber ()-1) *pageSize; } Public intGettotalpage () {/*** Total Pages*/      　　　　    if(totalrecord%pagesize==0) {returntotalrecord/pageSize; }return(Totalrecord/pagesize +1); }

　　2. DAO Layer Code: Queries the result based on the current index value and the number of records per page, and then encapsulates it into a user object and saves it to the list of the student class, returning it.

     PublicList<student> Getlimitstulist (intIndexintpageSize) {Jdbcutil Jdbcutil=NewJdbcutil (); Connection Con=jdbcutil.getconnection (); PreparedStatement PST=NULL; ResultSet RSet=NULL; List<student>list=NewArraylist<student>(); String SQL= "SELECT * FROM students limit?,?"; Try{PST=con.preparestatement (SQL); Pst.setint (1, index); Pst.setint (2, pageSize); RSet=Pst.executequery ();  while(Rset.next ()) {intId=rset.getint ("id"); String name=rset.getstring ("name"); String School=rset.getstring ("School"); DoubleScore=rset.getdouble ("Score"); List.add (NewStudent (ID, name, school, score)); }            } Catch(SQLException e) {e.printstacktrace (); } finally{jdbcutil.close (con, PST, rSet);        } System.out.println (list); returnlist; }

Not to be continued ....

Paging (displaying information in a database to a Web page)