JSP custom paging tag TAG whole process

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/**
 * Pagination processing tags
 *
 * @description
 * @DATE 2012-3-11 09:08:46 pm
 */ 
public class PageTag extends TagSupport { 
private int pageNo; 
private int pageSize = 10; 
private int totalSum; 
private int showPage = 10; 
private String url; 

public int getPageNo() { 
return pageNo; 
} 

public void setPageNo(int pageNo) { 
 = pageNo; 
} 

public int getPageSize() { 
return pageSize; 
} 

public void setPageSize(int pageSize) { 
 = pageSize; 
} 

public int getTotalSum() { 
return totalSum; 
} 

public void setTotalSum(int totalSum) { 
 = totalSum; 
} 

public int getShowPage() { 
return showPage; 
} 

public void setShowPage(int showPage) { 
 = showPage; 
} 

public String getUrl() { 
return url; 
} 

public void setUrl(String url) { 
 = url; 
} 

@Override 
public int doEndTag() throws JspException { 
if (pageSize == 0) { 
return TagSupport.SKIP_PAGE;// No pagination is displayed} else if (pageSize > totalSum) { 
return TagSupport.SKIP_BODY;// No pagination is displayed} 
JspWriter out = (); 
try { 
if ((";jsession?") == -1) { 
url += ";jsession?pageNo="; 
} else { 
url = ("\\?", ";jsession?"); 
if (("pageNo=") == -1) { 
url += "&pageNo="; 
} 
} 
} 
url = ().getContextPath() + url; 
VariablePage variablePage = new VariablePage(pageNo, totalSum, pageSize, url); 
(showPage); 
Page page = new HtmlPage(variablePage); 
(() + " " + () + " " + () + " " + () + " " + ()); 
} catch (IOException ex) { 
(); 
} 
return (); 
} 

@Override 
public void release() { 
url = null; 
pageNo = 0; 
totalSum = 0; 
pageSize = 10; 
(); 
} 

private static final long serialVersionUID = -2642907859641024483L; 
}

/**
 * HTML pagination class
 *
 * @description
 * @DATE 2012-3-11 10:33:14 pm
 */ 
public class HtmlPage extends Page { 
public HtmlPage(VariablePage variablePage) { 
super(variablePage); 
} 

public String pagination() { 
String printNo = ""; 
// If pages have been paging; and the number of pages is less than or equal to the number of pages to be displayedif ( > 1 &&  <= ) { 
return displayAll(); 
// If the number of pages: greater than the number of pages displayed} else if ( > 1 &&  > ) { 
if ( == 1) {// The current page is equal to the first pagereturn fromFirstPagePrint(); 
} else if ( == ) {// The current page is equal to the last pagereturn fromLastPagePrint(); 
} else {// If the current page: that is, it is not the home page or the last pageif ( % 2 == 0) {// Can be pagingint print$No =  / 2; 
if ( >= print$No) { 
int index$No =  - print$No; 
if ( + print$No >= ) { 
return fromLastPagePrint(); 
} else { 
if (index$No == 0) 
index$No = 1; 
for (int i = index$No; i < ( + index$No); i++) { 
if (i == ) {// If it is the current page: do not add the connection URLprintNo += (i + ); 
} else { 
printNo += (buildA(variablePage, i) + ); 
} 
} 
} 
} else { 
return fromFirstPagePrint(); 
} 
} else {// When the number of pages printed is not even:int print$No =  / 2 + 1; 
if ( >= print$No &&  + print$No < ) { 
int index$No =  - print$No + 1; 
for (int i = index$No; i <  + index$No; i++) { 
if (i == ) {// If it is the current page: do not add the connection URLprintNo += (i + ); 
} else { 
printNo += (buildA(variablePage, i) + ); 
} 
} 
} else if ( <= print$No) {// Start from the first pagereturn fromFirstPagePrint(); 
} else { 
return fromLastPagePrint(); 
} 
} 
} 
return (printNo); 
} else { 
return "1"; 
} 
} 

public String getBackpageNum() { 
if ( <= 1) { 
return buildSpan("Previous Page", variablePage); 
} else { 
return buildA("Previous Page", ( + ( - 1))); 
} 
} 

public String getNextpageNum() { 
if ( >= ) { 
return buildSpan("Next Page", variablePage); 
} else { 
return buildA("Next Page",  + ( + 1)); 
} 
} 

public String buildSpan(String text, VariablePage variablePage) { 
return "<span style=\"color:gray;\">" + text + "</span>"; 
} 

public String buildA(String text, String url) { 
return "<a href=\"" + url + "\">" + text + "</a>"; 
} 

public String buildA(VariablePage variablePage, int num) { 
return ("<a href=\"" +  + num + "\">" + num + "</a>"); 
} 
}

public abstract class Page { 
protected VariablePage variablePage; 

public Page(VariablePage variablePage) { 
 = variablePage; 
calculateTotalPage(); 
} 

public int getStartIndex() { 
return (getValidpageNum() - 1) * ; 
} 

public String getBackpageNum() { 
if ( <= 1) { 
return buildSpan("Previous Page", variablePage); 
} else { 
return buildA("Previous Page", () + ( - 1)); 
} 
} 

public String getNextpageNum() { 
if ( >= ) { 
return buildSpan("Next Page", variablePage); 
} else { 
return buildA("Next Page", () + ( + 1)); 
} 
} 

/**
 * Calculate the total number of pages
 */ 
private void calculateTotalPage() { 
if ( %  == 0) { 
 =  / ; 
} else { 
 =  /  + 1; 
} 
if ( < ) { 
 = ; 
} else if ( < 1) { 
 = 1; 
} 
} 

protected String displayAll() { 
StringBuilder sBuilder = new StringBuilder(10); 
(); 
for (int i = 1; i <= ; i++) { 
if (i == ) { 
(i + ); 
} else { 
(buildA(variablePage, i) + ); 
} 
} 
return (); 
} 

/**
 * Abstract the paging method
 *
 * @return
 */ 
public abstract String pagination(); 

/**
 * Implement printing from the first page
 *
 * @return
 */ 
protected final String fromFirstPagePrint() { 
StringBuffer buffer = new StringBuffer(100); 
for (int i = 1; i <= ; i++) { 
if (i == ) {// If it is the current page: do not add the connection URL(i + ); 
} else { 
(buildA(variablePage, i) + ); 
} 
} 
return (); 
} 

/**
 * Implementation to print from the last page
 *
 * @return
 */ 
protected final String fromLastPagePrint() { 
StringBuffer buffer = new StringBuffer(100); 
int startPage =  - ( - 1); 
for (int i = startPage; i <= ; i++) { 
if (i == ) {// If it is the current page: do not add the connection URL(i + ); 
} else { 
(buildA(variablePage, i) + ); 
} 
} 
return (); 
} 

public String getFirstNo() { 
if (isExistsPagination()) { 
return buildA("front page",  + 1); 
} else { 
return buildSpan("front page", variablePage); 
} 
} 

/**
 * Determine whether paging exists
 *
 * @return
 */ 
private boolean isExistsPagination() { 
if ( > 1 &&  > 1) { 
return true; 
} 
return false; 
} 

public String getLastNo() { 
if (isExistsPagination()) { 
return buildA("Last Page",  + ); 
} else { 
return buildSpan("Last Page", variablePage); 
} 
} 

protected int getValidpageNum() { 
if ( < ) { 
return  = ; 
} else if ( < 1) { 
return  = 1; 
} else { 
return ; 
} 
} 

public VariablePage getPageContant() { 
return ; 
} 

public abstract String buildSpan(String text, VariablePage variablePage); 

public abstract String buildA(String text, String url); 

public abstract String buildA(VariablePage variablePage, int num); 

public String printModifyPageSize(int pageSize){ 
StringBuilder builder=new StringBuilder(100); 
("Each page<input type='text' id='pageSize' style='width:20px' maxlength='2' name='pageSize'"); 
if(pageSize>0){ 
(" value='"+pageSize+"' "); 
} 
("/>"); 
return (); 
} 
}

/**
 * Pagination basic variables
 *
 * @description
 * @DATE 2012-3-11 10:34:00 pm
 */ 
public class SimpleVariable { 
/**
 * Show page number
 */ 
protected int showPageNum = 10; 
/**
 * Connection URL
 */ 
protected String url = null; 
/**
 * Current page number
 */ 
protected int pageNo = 1; 
/**
 * Total page number
 */ 
protected int totalPage = 1; 
/**
 * Total number of
 */ 
protected int totalSum = 0; 
/**
 * Number of pieces displayed per page
 */ 
protected int pageSize = 10; 

public String getUrl() { 
return url; 
} 

public void setUrl(String url) { 
 = url; 
} 

public int getTotalPage() { 
return totalPage; 
} 

public void setTotalPage(int totalPage) { 
 = totalPage; 
} 

public int getTotalSum() { 
return totalSum; 
} 

public void setTotalSum(int totalSum) { 
 = totalSum; 
} 

public int getPageSize() { 
return pageSize; 
} 

public void setPageSize(int pageSize) { 
 = pageSize; 
} 

public int getShowPageNum() { 
return showPageNum; 
} 

public void setShowPageNum(int showPageNum) { 
 = showPageNum; 
} 

public int getPageNo() { 
return pageNo; 
} 

public void setPageNo(int pageNo) { 
 = pageNo; 
} 
} 

/**
 * Pagination variables
 *
 * @description
 * @DATE 2012-3-11 10:34:08 pm
 */ 
public class VariablePage extends SimpleVariable { 
protected String split = " "; 
protected String style = "class='page'"; 

public VariablePage(int pageNo, int totalSum, int pageSize, String url) { 
pageNo = pageNo < 1 ? 1 : pageNo; 
 = pageNo; 
 = totalSum; 
 = url; 
 = pageSize; 
} 

public VariablePage(int pageNum, int totalSum, String url) { 
pageNum = pageNum < 1 ? 1 : pageNum; 
 = pageNum; 
 = totalSum; 
 = url; 
} 

public String getSplit() { 
return split; 
} 

public void setSplit(String split) { 
 = split; 
} 

}

<%@taglib uri="/taglibs/page" prefix="page" %>

<page:htmlPage pageNo="${pageNo}" url="your_url" totalSum="${totalSum}" showPage="10" pageSize="12"/>