Summary of common tools in the Web

Linked action classes for the database

 PackageUtils;Importjava.sql.Connection;ImportJava.sql.DriverManager;Importjava.sql.PreparedStatement;ImportJava.sql.ResultSet;Importjava.sql.SQLException; Public classDBConnection {Private Static FinalString dbdriver = "Com.mysql.jdbc.Driver";//driver class class name    Private Static FinalString Dburl = "Jdbc:mysql://localhost:3306/db_votemanage";//Connection URL    Private Static FinalString DBUSER = "root";//Database user name    Private Static FinalString Dbpassword = "root";//Database Password     Public StaticConnection getconnection () {Connection conn=NULL;//declaring a Connection object        Try{class.forname (dbdriver); //Registration Driverconn = Drivermanager.getconnection (Dburl,dbuser,dbpassword);//Get the Connection object}Catch(ClassNotFoundException e) {//The capture driver class could not find the exceptionE.printstacktrace (); } Catch(SQLException e) {//Capturing SQL ExceptionsE.printstacktrace (); }        returnConn; }     Public Static voidClose (Connection conn) {//Close the Connection object        if(Conn! =NULL) {//if the Conn connection object is not empty            Try{conn.close (); //close the Conn Connection object Object}Catch(SQLException e) {e.printstacktrace (); }        }    }     Public Static voidClose (PreparedStatement pstmt) {//Close preprocessed Objects        if(Pstmt! =NULL) {//if the pstmt preprocessing object is not empty            Try{pstmt.close (); //Close pstmt preprocessing objects}Catch(SQLException e) {e.printstacktrace (); }        }    }     Public Static voidClose (ResultSet rs) {//Close result Set object        if(rs! =NULL) {//if the RS result set object is not NULL            Try{rs.close (); //Close RS Result set object}Catch(SQLException e) {e.printstacktrace (); }        }    }}

Tool class for pagination

 PackageUtils; Public classPage {Private intEverypage;//shows the number of records per page    Private intTotalCount;//Total Record Count    Private intTotalpage;//Total Pages    Private intCurrentPage;//Current Page    Private intBeginindex;//Query Start point    Private BooleanHasprepage;//do you have a previous page    Private BooleanHasnextpage;//do you have the next page ?     PublicPage (intEverypage,intTotalCount,intTotalpage,intCurrentPage,intBeginindex,BooleanHasprepage,BooleanHasnextpage) {//Custom Construction Methods         This. Everypage =everypage;  This. TotalCount =TotalCount;  This. Totalpage =Totalpage;  This. currentpage =currentpage;  This. Beginindex =Beginindex;  This. Hasprepage =Hasprepage;  This. Hasnextpage =Hasnextpage; }     PublicPage () {}//default constructor     Public intGeteverypage () {//get the number of records displayed per page        returneverypage; }     Public voidSeteverypage (intEverypage) {//set the number of records to display per page         This. Everypage =everypage; }     Public intGettotalcount () {//get total Record Count        returnTotalCount; }     Public voidSettotalcount (intTotalCount) {//set total number of records         This. TotalCount =TotalCount; }     Public intGettotalpage () {//Get Total Pages        returnTotalpage; }     Public voidSettotalpage (intTotalpage) {//Set Total pages         This. Totalpage =Totalpage; }     Public intGetcurrentpage () {//get the current page        returncurrentpage; }     Public voidSetcurrentpage (intCurrentPage) {//set the current page         This. currentpage =currentpage; }     Public intGetbeginindex () {//get query start point        returnBeginindex; }     Public voidSetbeginindex (intBeginindex) {//set query start point         This. Beginindex =Beginindex; }     Public BooleanIshasprepage () {//get a previous page        returnHasprepage; }     Public voidSethasprepage (BooleanHasprepage) {//set whether there is a previous page         This. Hasprepage =Hasprepage; }     Public BooleanIshasnextpage () {//get the next page        returnHasnextpage; }     Public voidSethasnextpage (BooleanHasnextpage) {//set whether there is a next page         This. Hasnextpage =Hasnextpage; }}------------------------------------------------------------------------------- PackageUtils;/** Paging Information auxiliary class*/ Public classPageutil { Public StaticPage Createpage (intEverypage,intTotalCount,intCurrentPage) {//Create a paging information objectEverypage =geteverypage (everypage); CurrentPage=getcurrentpage (currentpage); intTotalpage =gettotalpage (Everypage, totalcount); intBeginindex =Getbeginindex (Everypage, currentpage); BooleanHasprepage =gethasprepage (currentpage); BooleanHasnextpage =gethasnextpage (Totalpage, currentpage); return NewPage (Everypage, TotalCount, Totalpage, CurrentPage, Beginindex, Hasprepage, hasnextpage); }     Public Static intGeteverypage (intEverypage) {//get the number of records displayed per page        returnEverypage = = 0? 10: everypage; }     Public Static intGetcurrentpage (intCurrentPage) {//get the current page        returnCurrentPage = = 0? 1: currentpage; }     Public Static intGettotalpage (intEverypage,intTotalCount) {//Get Total Pages        intTotalpage = 0; if(TotalCount! = 0 &&totalcount% Everypage = = 0) {Totalpage= TotalCount/everypage; } Else{totalpage= Totalcount/everypage + 1; }        returnTotalpage; }     Public Static intGetbeginindex (intEverypage,intCurrentPage) {//Get start position        return(currentPage-1) *everypage; }     Public Static BooleanGethasprepage (intCurrentPage) {//get a previous page        returnCurrentPage = = 1?false:true; }     Public Static BooleanGethasnextpage (intTotalpage,intCurrentPage) {//get a previous page        returnCurrentPage = = Totalpage | | Totalpage = = 0?false:true; }}

Summary of common tools in the Web