Currently, the best JSP paging technology

Preface
In the process of using the database, it is inevitable to use the paging function, but the JDBC specification does not solve this well. Many of my friends have their own solutions for this demand. For example, we use a collection class such as Vector to save the retrieved data first and then pagination. However, this method has poor availability, which is completely different from the JDBC interface and does not support different types of fields. A solution with good compatibility with JDBC is provided here.
JDBC and paging
Sun's JDBC specification is sometimes dumbfounded. In JDBC1.0, you can only perform the next () operation on a result set instead of rolling it backwards, this directly leads to the failure to obtain the size of the result set when only one SQL query is executed. Therefore, if you are using the JDBC1.0 driver, paging is almost impossible.
Fortunately, Sun's JDBC2 specification makes up for this deficiency and adds the frontend and backend scrolling operations of the result set. Although it still cannot directly support paging, however, you can write your own ResultSet that supports pagination on this basis.
Implementation methods related to specific databases
Some databases, such as Mysql and Oracle, have their own paging methods. For example, Mysql can use the limit clause, and Oracle can use ROWNUM to limit the size and start position of the result set. Take Mysql as an example. The typical code is as follows:
// Calculate the total number of records
String SQL = "SELECT Count (*) AS total" + this. QueryPart;
Rs = db.exe cuteQuery (SQL );
If (rs. next ())
Total = rs. getInt (1 );
// Set the current page number and total page number
TPages = (int) Math. ceil (double) this. Total/this. MaxLine );
CPages = (int) Math. floor (double) Offset/this. MaxLine + 1 );
// Retrieve the required records based on conditions
If (Total> 0 ){
SQL = Query + "LIMIT" + Offset + "," + MaxLine;
Rs = db.exe cuteQuery (SQL );
    }
Return rs;
  }
Without a doubt, this code will be beautiful when the database is Mysql, but as a general class (in fact, what I want to provide later is part of a general class library ), we need to adapt to different databases, and applications based on this class (database) may also use different databases. Therefore, we will not use this method.