欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页  >  web前端

JSP自定义分页标签TAG全过程

程序员文章站 2022-04-29 19:02:46
...
首先我们需要在WEB-INF/tld/目录下创建page.tld文件
<?xml version="1.0" encoding="ISO-8859-1"?> 
<taglib> 
<tlib-version>1.0</tlib-version> 
<jsp-version>1.2</jsp-version> 
<short-name>page</short-name> 
<uri>http://www.kevin.com/taglibs/page</uri> 
<tag> 
<name>htmlPage</name> 
<tag-class>com.lss.common.tag.PageTag</tag-class> 
<body-content>JSP</body-content> 
<description>htmlPage Tag</description> 
<attribute> 
<name>pageNo</name> 
<required>false</required> 
<rtexprvalue>true</rtexprvalue> 
</attribute> 
<attribute> 
<name>pageSize</name> 
<required>false</required> 
<rtexprvalue>true</rtexprvalue> 
</attribute> 
<attribute> 
<name>totalSum</name> 
<required>true</required> 
<rtexprvalue>true</rtexprvalue> 
</attribute> 
<attribute> 
<name>url</name> 
<required>true</required> 
<rtexprvalue>true</rtexprvalue> 
</attribute> 
<attribute> 
<name>showPage</name> 
<required>false</required> 
<rtexprvalue>true</rtexprvalue> 
</attribute> 
</tag> 
</taglib>
package com.lss.common.tag; 
 
import java.io.IOException; 
 
import javax.servlet.jsp.JspException; 
import javax.servlet.jsp.JspWriter; 
import javax.servlet.jsp.tagext.TagSupport; 
 
import com.lss.common.page.HtmlPage; 
import com.lss.common.page.Page; 
import com.lss.common.page.VariablePage; 
 
/** 
* 分页处理标签 
* 
* @description 
* @DATE 2012-3-11下午09:08:46 
*/
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) { 
this.pageNo = pageNo; 
} 
 
public int getPageSize() { 
return pageSize; 
} 
 
public void setPageSize(int pageSize) { 
this.pageSize = pageSize; 
} 
 
public int getTotalSum() { 
return totalSum; 
} 
 
public void setTotalSum(int totalSum) { 
this.totalSum = totalSum; 
} 
 
public int getShowPage() { 
return showPage; 
} 
 
public void setShowPage(int showPage) { 
this.showPage = showPage; 
} 
 
public String getUrl() { 
return url; 
} 
 
public void setUrl(String url) { 
this.url = url; 
} 
 
@Override
public int doEndTag() throws JspException { 
if (pageSize == 0) { 
return TagSupport.SKIP_PAGE;// 不显示分页 
} else if (pageSize > totalSum) { 
return TagSupport.SKIP_BODY;// 不显示分页 
} 
JspWriter out = pageContext.getOut(); 
try { 
if (url.indexOf(";jsessionid=") == -1) { 
if (url.indexOf("?") == -1) { 
url += ";jsessionid=" + pageContext.getSession().getId() + "?pageNo="; 
} else { 
url = url.replaceFirst("\\?", ";jsessionid=" + pageContext.getSession().getId() + "?"); 
if (url.indexOf("pageNo=") == -1) { 
url += "&pageNo="; 
} 
} 
} 
url = pageContext.getServletContext().getContextPath() + url; 
VariablePage variablePage = new VariablePage(pageNo, totalSum, pageSize, url); 
variablePage.setShowPageNum(showPage); 
Page page = new HtmlPage(variablePage); 
out.print(page.getFirstNo() + " " + page.getBackpageNum() + " " + page.pagination() + " " + page.getNextpageNum() + " " + page.getLastNo()); 
} catch (IOException ex) { 
ex.printStackTrace(); 
} 
return super.doEndTag(); 
} 
 
@Override
public void release() { 
url = null; 
pageNo = 0; 
totalSum = 0; 
pageSize = 10; 
super.release(); 
} 
 
private static final long serialVersionUID = -2642907859641024483L; 
}
/** 
* HTML 分页类 
* 
* @description 
* @DATE 2012-3-11下午10:33:14 
*/
public class HtmlPage extends Page { 
public HtmlPage(VariablePage variablePage) { 
super(variablePage); 
} 
 
public String pagination() { 
String printNo = ""; 
// 如果已分页;并且页数小于等于要显示的页数 
if (variablePage.totalPage > 1 && variablePage.totalPage <= variablePage.showPageNum) { 
return displayAll(); 
// 如果分页数:大于显示的页码数 
} else if (variablePage.totalPage > 1 && variablePage.totalPage > variablePage.showPageNum) { 
if (variablePage.pageNo == 1) {// 当前页等于第一页 
return fromFirstPagePrint(); 
} else if (variablePage.pageNo == variablePage.totalPage) {// 当前页等于最后一页 
return fromLastPagePrint(); 
} else {// 如果当前页:即不是首页也不是尾页 
if (variablePage.showPageNum % 2 == 0) {// 可以平分页码 
int print$No = variablePage.showPageNum / 2; 
if (variablePage.pageNo >= print$No) { 
int index$No = variablePage.pageNo - print$No; 
if (variablePage.pageNo + print$No >= variablePage.totalPage) { 
return fromLastPagePrint(); 
} else { 
if (index$No == 0) 
index$No = 1; 
for (int i = index$No; i < (variablePage.showPageNum + index$No); i++) { 
if (i == variablePage.pageNo) {// 如果是当前页:不添加连接URL 
printNo += (i + variablePage.split); 
} else { 
printNo += (buildA(variablePage, i) + variablePage.split); 
} 
} 
} 
} else { 
return fromFirstPagePrint(); 
} 
} else {// 打印页数不是偶数时: 
int print$No = variablePage.showPageNum / 2 + 1; 
if (variablePage.pageNo >= print$No && variablePage.pageNo + print$No < variablePage.totalPage) { 
int index$No = variablePage.pageNo - print$No + 1; 
for (int i = index$No; i < variablePage.showPageNum + index$No; i++) { 
if (i == variablePage.pageNo) {// 如果是当前页:不添加连接URL 
printNo += (i + variablePage.split); 
} else { 
printNo += (buildA(variablePage, i) + variablePage.split); 
} 
} 
} else if (variablePage.pageNo <= print$No) {// 从第一页开始 
return fromFirstPagePrint(); 
} else { 
return fromLastPagePrint(); 
} 
} 
} 
return (printNo); 
} else { 
return "1"; 
} 
} 
 
public String getBackpageNum() { 
if (variablePage.pageNo <= 1) { 
return buildSpan("上一页", variablePage); 
} else { 
return buildA("上一页", (variablePage.url + (variablePage.pageNo - 1))); 
} 
} 
 
public String getNextpageNum() { 
if (variablePage.pageNo >= variablePage.totalPage) { 
return buildSpan("下一页", variablePage); 
} else { 
return buildA("下一页", variablePage.url + (variablePage.pageNo + 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=\"" + variablePage.url + num + "\">" + num + "</a>"); 
} 
}
public abstract class Page { 
protected VariablePage variablePage; 
 
public Page(VariablePage variablePage) { 
this.variablePage = variablePage; 
calculateTotalPage(); 
} 
 
public int getStartIndex() { 
return (getValidpageNum() - 1) * variablePage.pageSize; 
} 
 
public String getBackpageNum() { 
if (variablePage.pageNo <= 1) { 
return buildSpan("上一页", variablePage); 
} else { 
return buildA("上一页", variablePage.getUrl() + (variablePage.pageNo - 1)); 
} 
} 
 
public String getNextpageNum() { 
if (variablePage.pageNo >= variablePage.totalPage) { 
return buildSpan("下一页", variablePage); 
} else { 
return buildA("下一页", variablePage.getUrl() + (variablePage.pageNo + 1)); 
} 
} 
 
/** 
* 计算总页数 
*/
private void calculateTotalPage() { 
if (variablePage.totalSum % variablePage.pageSize == 0) { 
variablePage.totalPage = variablePage.totalSum / variablePage.pageSize; 
} else { 
variablePage.totalPage = variablePage.totalSum / variablePage.pageSize + 1; 
} 
if (variablePage.totalPage < variablePage.pageNo) { 
variablePage.pageNo = variablePage.totalPage; 
} else if (variablePage.pageNo < 1) { 
variablePage.pageNo = 1; 
} 
} 
 
protected String displayAll() { 
StringBuilder sBuilder = new StringBuilder(10); 
sBuilder.append(variablePage.split); 
for (int i = 1; i <= variablePage.totalPage; i++) { 
if (i == variablePage.pageNo) { 
sBuilder.append(i + variablePage.split); 
} else { 
sBuilder.append(buildA(variablePage, i) + variablePage.split); 
} 
} 
return sBuilder.toString(); 
} 
 
/** 
* 抽象出分页方法 
* 
* @return 
*/
public abstract String pagination(); 
 
/** 
* 实现从第一页开始打印 
* 
* @return 
*/
protected final String fromFirstPagePrint() { 
StringBuffer buffer = new StringBuffer(100); 
for (int i = 1; i <= variablePage.showPageNum; i++) { 
if (i == variablePage.pageNo) {// 如果是当前页:不添加连接URL 
buffer.append(i + variablePage.split); 
} else { 
buffer.append(buildA(variablePage, i) + variablePage.split); 
} 
} 
return buffer.toString(); 
} 
 
/** 
* 实现从最后一页开始打印 
* 
* @return 
*/
protected final String fromLastPagePrint() { 
StringBuffer buffer = new StringBuffer(100); 
int startPage = variablePage.totalPage - (variablePage.showPageNum - 1); 
for (int i = startPage; i <= variablePage.totalPage; i++) { 
if (i == variablePage.pageNo) {// 如果是当前页:不添加连接URL 
buffer.append(i + variablePage.split); 
} else { 
buffer.append(buildA(variablePage, i) + variablePage.split); 
} 
} 
return buffer.toString(); 
} 
 
public String getFirstNo() { 
if (isExistsPagination()) { 
return buildA("首页", variablePage.url + 1); 
} else { 
return buildSpan("首页", variablePage); 
} 
} 
 
/** 
* 判断是否存在分页 
* 
* @return 
*/
private boolean isExistsPagination() { 
if (variablePage.totalSum > 1 && variablePage.totalPage > 1) { 
return true; 
} 
return false; 
} 
 
public String getLastNo() { 
if (isExistsPagination()) { 
return buildA("尾页", variablePage.url + variablePage.totalPage); 
} else { 
return buildSpan("尾页", variablePage); 
} 
} 
 
protected int getValidpageNum() { 
if (variablePage.totalPage < variablePage.pageNo) { 
return variablePage.pageNo = variablePage.totalPage; 
} else if (variablePage.pageNo < 1) { 
return variablePage.pageNo = 1; 
} else { 
return variablePage.pageNo; 
} 
} 
 
public VariablePage getPageContant() { 
return this.variablePage; 
} 
 
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); 
builder.append("每页<input type='text' id='pageSize' style='width:20px' maxlength='2' name='pageSize'"); 
if(pageSize>0){ 
builder.append(" value='"+pageSize+"' "); 
} 
builder.append("/>条"); 
return builder.toString(); 
} 
}
/** 
* 分页基础变量 
* 
* @description 
* @DATE 2012-3-11下午10:34:00 
*/
public class SimpleVariable { 
/** 
* 显示页码 
*/
protected int showPageNum = 10; 
/** 
* 连接URL 
*/
protected String url = null; 
/** 
* 当前页码 
*/
protected int pageNo = 1; 
/** 
* 总页码 
*/
protected int totalPage = 1; 
/** 
* 总条数 
*/
protected int totalSum = 0; 
/** 
* 每页显示条数 
*/
protected int pageSize = 10; 
 
public String getUrl() { 
return url; 
} 
 
public void setUrl(String url) { 
this.url = url; 
} 
 
public int getTotalPage() { 
return totalPage; 
} 
 
public void setTotalPage(int totalPage) { 
this.totalPage = totalPage; 
} 
 
public int getTotalSum() { 
return totalSum; 
} 
 
public void setTotalSum(int totalSum) { 
this.totalSum = totalSum; 
} 
 
public int getPageSize() { 
return pageSize; 
} 
 
public void setPageSize(int pageSize) { 
this.pageSize = pageSize; 
} 
 
public int getShowPageNum() { 
return showPageNum; 
} 
 
public void setShowPageNum(int showPageNum) { 
this.showPageNum = showPageNum; 
} 
 
public int getPageNo() { 
return pageNo; 
} 
 
public void setPageNo(int pageNo) { 
this.pageNo = pageNo; 
} 
}
/** 
* 分页变量 
* 
* @description 
* @DATE 2012-3-11下午10:34:08 
*/
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; 
super.pageNo = pageNo; 
this.totalSum = totalSum; 
this.url = url; 
this.pageSize = pageSize; 
} 
 
public VariablePage(int pageNum, int totalSum, String url) { 
pageNum = pageNum < 1 ? 1 : pageNum; 
super.pageNo = pageNum; 
this.totalSum = totalSum; 
this.url = url; 
} 
 
public String getSplit() { 
return split; 
} 
 
public void setSplit(String split) { 
this.split = split; 
} 
 
}

#需要使用该分页标签的JSP 使用方法如下:

JSP 头部引入

<%@taglib uri="http://www.kevin.com/taglibs/page" prefix="page" %>

使用以下标签生成分页HTML代码

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


更多JSP自定义分页标签TAG全过程相关文章请关注PHP中文网!

相关标签: 分页标签 tag