Encapsulate the paging logic using components-page turning of JSP and JSP pages

Page flip control is required for displaying data in the form of a list, which is basically used in all modules of the project. To maximize the reusability and portability of page turning, the page turning logic is encapsulated in the form of components.

Analysis of paging Controller

Description:

The page flip controller is used to control the page flip content display and page flip operations on Web pages. By calling JSP, the page content is displayed on the web page. It supports multiple display modes and styles.

Design of paging Controller

Create a pageconfig class, a page class, And a pageview class for the paging controller respectively.

· Pageconfig. Java

Class

Class	Pageconfig
Statement	Public class
Description	This class is used to save the page property values, such as the number of lines displayed on each page.
Superclass
Run

Attribute description

Attribute	Attribute description	Definition
[Pageconfig]
| -- Page_size	Page size	Public static final int
| -- Page_size_small	Small page size	Public static final int
| -- Page_size_normal	Normal page size	Public static final int
| -- Page_size_big	Size of a large page	Public static final int
| -- Page_size_bigger	Large page size	Public static final int
| -- Page_size_biggest	Maximum page size	Public static final int

· Page. Java

Class

Class	Page
Statement	Public class
Description	This class is used to save the page property values, such as the number of lines displayed on each page.
Superclass
Run	Java. Lang. serializable

Attribute description

Attribute	Name	Attribute description	Data Type
| -- Empty_page	Blank Page	Describe a blank page, that is, a page without content.	Page Object
| -- Objects	Result set list	Result set list	Java. util. List or Java. util. Vector
| -- Start	Start Record Number	Start record number, starting from 0	Positive Integers and 0
| -- End	End Record Number	End Record Number	Positive Integers and 0
| -- Viewstart	The start record number is displayed on the page.	The start record number is displayed on the page, starting from 1.	Positive Integer
| -- Viewend	Display the end record number on the page	Display the end record number on the page	Positive Integer
| -- Hasprevious	Whether the previous page is enabled or not	Whether the previous page is enabled or not	Boolean Value
| -- Previouspagenumber	Page number of the previous page	Page number of the previous page	Positive Integers and 0
| -- Hasnext	Whether there is a next page Switch	Whether there is a next page Switch	Boolean Value
| -- Nextpagenumber	Page number of the next page	Page number of the next page	Positive Integers and 0
| -- Total	Total number of rows	Total number of rows	Positive Integers and 0
| -- Totalpage	Total number of pages	Total number of pages
| -- Currentpagenumber	Current page	Current page of Description	Positive Integers and 0
| -- Pagesize	Page size	Number of lines on each page	Positive Integers and 0

Constructor

Constructor	Constructor description	Parameters
[Page]
| -- Page (list l, int S, Boolean hasnext)	Create page	L number of records starting from S in the result set, starting from 0. Does hasnext have a next page switch?
| -- Page (list l, int S, Boolean hasnext, int total)	Create page	L The number of records starting from S in the result set, starting from 0. Does hasnext have the number of rows in the switch total for the next page?
| -- Page (list l, int S, int size, Boolean hasnext, int total)	Create page	L number of records starting from S in the result set, starting from 0. Size: number of rows on each page. hasnext: whether there is a switch on the next page. Total: Total number of rows.
| -- Page (list l, int num, int size, int total)	Create page	L result set num current is the page size, number of rows on each page total number of rows of records
| -- Page (list l)	Create page without Paging	L result set

Method

Method	Method description	Return Value
[Page]
| -- Autocalculate ()	Automatically calculates the value of other attributes based on the current page, page size, and total number of rows.	Private void
| -- Getlist ()	Get result set	Public list
| -- Getviewstart ()	Obtain the start record number displayed on the page, starting from 1	Public int
| -- Getviewend ()	Obtain the end record number displayed on the page	Public int
| -- Hasnextpage ()	Whether the next page exists	Public Boolean
| -- Haspreviouspage ()	Whether the previous page exists	Public Boolean
| -- Getpreviouspagenumber ()	Retrieve the page number of the previous page	Public int
| -- Getnextpagenumber ()	Obtain the page number of the next page	Public int
| -- Gettotal ()	Total number of records in the result set	Public int
| -- Gettotalpage ()	Obtain the total number of pages	Public int
| -- Getcurrentpagenumber ()	Obtain the current page number	Public int
| -- Getpagesize ()	How many rows of records per page are obtained	Public int
| -- Getstartofnextpage ()	Obtains the number of records starting from the next page in the result set, starting from 0.	Public int
| -- Getstartofpreviouspage ()	Obtains the number of records starting from the previous page in the result set, starting from 0.	Public int
| -- Getsize ()	Obtain the number of records on the current page	Public int
| -- Isempty ()	Checks whether the current page is blank. If the current page is blank, true is returned. Otherwise, false is returned.	Public Boolean

Pageview. Java

Class

Class	Pageview
Statement	Public class
Description	By calling JSP, the page content is displayed on the web page. Images and buttons are not supported. Only text is supported. Usage: the JSP page is defined as follows: <% Pageview view = new pageview (request, out, page); %> display by default <% view. setvisible (true); %> display in the specified form <% view. setvisible (true,); %>
Superclass
Run

Attribute description

Attribute	Name	Attribute description	Data Type
[Pageview]
| -- Currenturl	URL of the current page	URL of the current page	String
| -- Style	Style	Style	String
| -- Usesquarebrackets	Whether to add a [] Switch	Add "[" and "]" on both sides of "Previous Page"	Boolean Value
| -- Page	Web Page	Web Page	Page Object

Constructor

Constructor	Constructor description	Parameters
[Pageview]
| -- Pageview (httpservletrequest request, jspwriter out, page ))	Create a paging content	The request client sends an out page to output the page web page.

Method

method	method description	return value
[pageview]
| -- setvisible (Boolean visible)	the page content is displayed by default. If visible is true, the page content is displayed. Otherwise, the page content is not displayed.	Public void
| -- setvisible (Boolean visible, int style, int order)	the pagination content is displayed in the specified format. If visible is true, the pagination content is displayed. Otherwise, the pagination content is not displayed.	Public void
| -- setvisible (Boolean visible, Boolean usesquarebrackets, int style, int order)	the pagination content is displayed in the specified format. If visible is true, the pagination content is displayed. Otherwise, the pagination content is not displayed.	Public void
| -- viewpage (Boolean usesquarebrackets, int style, int order)	the page content is displayed in the specified form. Order is 0, indicating the complete form. displayed in the following order: Total: 18 pages: 2 current page: 1 per page: 10 go to the front and back pages of the home page to □□□order as 1, which indicates a concise form. It is displayed in the following order: 1/2order is 2 at the end of the front and back pages, complete Form 2, displayed in the following order: Total: 18 per page: 10 go to □□□□home page front page and back page 1/2	Public void

Code of the paging Controller

You only need to encode the code based on the design of the paging controller.

Page flip Controller componentSource code

A) pageconfig. Java

B) page. Java

C) pageview. Java

SourceCode: Download Now

Call of paging Controller

The call of the paging controller is too simple. The call method is as follows:

· Import the paging controller package

<% @ Page import = "Java. util. list, Com. cwap. oa. controller. web. page. page, Com. cwap. oa. controller. web. page. pageview "%>

· Create a Page Object. Page. empty_page is a blank page.

Page page = page. empty_page;

· Create A pageview object

<% Pageview view = new pageview (request, out, page); %>

· Display page content:

Display by default

<% View. setvisible (true); %>

Display as specified

<% View. setvisible (true, 0, 1); %>

· Example of calling the paging Controller

The following is an example called in a JSP in the Forum section to display the list of all Forum sections. only part of the code is listed below:

<% @ Page Language = "Java" %> <% @ page contenttype = "text/html; charset = GBK" %> <% @ page import = "Java. util. list, Com. cwap. oa. controller. web. page. pageview, Com. cwap. oa. controller. web. page. page "%> <JSP: usebean id =" forumboardhelper "Scope =" page "class =" com. club8090.forum. forumboard. client. forumboardclienthelper "/> <% string TMP = request. getparameter ("pagenumber"); int pagenumber = 0; If (TMP = NULL | TMP. equals ("")) {Pagenumber = 1;} else {try {pagenumber = integer. parseint (TMP);} catch (Java. lang. nullpointerexception NPE) {pagenumber = 1;} catch (Java. lang. numberformatexception NFE) {pagenumber = 1 ;}} page = page. empty_page; // The page is initialized to page. empty_page blank page = forumboardhelper. getallforumboards (pagenumber); %>... <Table> <tr> <TD> NO. </TD> <TD> name </TD> <TD> description abstract </TD> </tr> <% list items = page. getlist (); If (items. isempty () {out. println ("<tr colspan = 3> no record exists </tr>");} else {int no; // The number of rows displayed on the page for (INT I = 0; I <items. size (); I ++) {forumboardmodel = (forumboardmodel) items. get (I); NO = page. getviewstart () + I; %> // display the record list <tr> <TD> <% = No %> </TD> <% = forumboardmodel. getname () %> </TD> <% = forumboardmode L. getsummary () %> </TD> </tr> <%} pageview view = new pageview (request, out, page); view. setvisible (true,) ;}%> </table>...