JSP的自定义TagSupport标签实现分页

1、在pom.xml中配置相关jar包

<dependency>
	<groupId>commons-fileupload</groupId>
	<artifactId>commons-fileupload</artifactId>
	<version>1.3.1</version>
</dependency>

 

2、需要在WEB-INF下面配置myTag.tlg文件，内容如下

<?xml version="1.0" encoding="UTF-8"?>
<taglib version="2.1" xmlns="http://java.sun.com/xml/ns/javaee"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
		http://java.sun.com/xml/ns/javaee/web-jsptaglibrary_2_1.xsd">
		
	<tlib-version>1.0</tlib-version>
	<short-name>mt</short-name>

	<!-- 标签库配置文件 -->
    <tag>
    	<name>page</name>
    	<!-- PageTag的类路径 -->
    	<tag-class>com.bs.beststore.web.tags.PageTag</tag-class>
    	<body-content>empty</body-content>
    	<attribute>
    		<name>href</name>	<!-- 链接 -->
    		<required>true</required>
    		<rtexprvalue>true</rtexprvalue>
    	</attribute>
    	<attribute>
    		<name>rows</name>	<!-- 每页行数 -->
    		<required>true</required>
    		<rtexprvalue>true</rtexprvalue>
    	</attribute>
    	<attribute>
    		<name>total</name>	<!-- 总行数 -->
    		<required>true</required>
    		<rtexprvalue>true</rtexprvalue>
    	</attribute>
    </tag>
    
</taglib>

3、写PageTag.java文件

package com.bs.beststore.web.tags;

import java.io.IOException;

import javax.servlet.jsp.JspException;
import javax.servlet.jsp.tagext.TagSupport;

public class PageTag extends TagSupport {
	
	private static final long serialVersionUID = 1L;
	private long total;		//总数
	private int rows;		//每页行数
	private String href;	//请求地址
	
	public int doStartTag() throws JspException {
		int totalPage=0;
		if(total>0 && rows>0){
			totalPage=((int)total%rows)==0 ? (int)total/rows : (int)total/rows+1; //总页数
		}
		int pageNo=0;		//当前页号
		if(total<=0 || rows<=0 || totalPage<=0){
			return SKIP_BODY;
		}
		
		while(pageNo<totalPage){
			//String pageName=  pageNo==0 ? "首页" : pageNo==totalPage-1 ? "尾页" : (pageNo+1+"");
			String pageName=null;
			if(pageNo==0){
				pageName="首页";
			}else if(pageNo==totalPage-1){
				pageName="尾页";
			}else{
				pageName=pageNo+1+"";
			}
			
			pageNo++;
			
			String wen=href.contains("?") ? "&" : "?";
			
			String s=String.format("<a href='%s%spage=%s&rows=%s'>%s</a>", href,wen,pageNo,rows,pageName);
			try {
				pageContext.getOut().println(s);
			} catch (IOException e) {
				new JspException();
			}
		}
		return EVAL_BODY_INCLUDE;
	}

	public void setTotal(long total) {
		this.total = total;
	}

	public void setRows(int rows) {
		this.rows = rows;
	}

	public void setHref(String href) {
		this.href = href;
	}
	
}

4、在JSP页面加入指令

<%@ taglib uri="/WEB-INF/myTag.tld" prefix="mt"%>

5、JSP页面使用

<mt:page href="userCollectionPage.do" total="${total }" rows="${rows }"/>

6、写控制层，记得要判断当前页号

@RequestMapping(value="userCollectionPage.do")
	public String userCollectionPage(HttpServletRequest request) {
		Human human = (Human) request.getSession().getAttribute("loginHuman");
		String page=request.getParameter("page");
		if(page==null) {
			page="1";
		}
		int rows=8;	//每页条数
		long total=favoriteBiz.findAllTotal(human.getHid());	//总条数
		int totalPage=(int) (total/rows==0 ? total/rows: total/rows+1);	//总页数
		request.setAttribute("totalPage", totalPage);
		if(Integer.parseInt(page)<=1) {
			page="1";
		}
		if(Integer.parseInt(page)>=totalPage && totalPage>0){
			page=totalPage+"";
		}
		request.setAttribute("page", page);	//当前页数
		List<Map<String, Object>> list = favoriteBiz.findAllFavorite(human.getHid(),Integer.valueOf(page),rows);
		if(list.size()>0) {
			request.setAttribute("list", list);
			request.setAttribute("total", total);
			request.setAttribute("rows", rows);
		}
		return "userCollection";
	}