jsp自定义分页标签

1、web工程的整体结构

2、Eclipse中tld文件的构建方法
3、编码

package mytags;

import java.io.IOException;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.tagext.TagSupport;

public class PagerTag extends TagSupport {
	/**
	 * 
	 */
	private static final long serialVersionUID = -3066943125964706748L;
	private String url; 		//表单提交地址
	private int recordCount;	//记录总数
	private int pageNo;			//当前页码
	private int pageSize;		//页面容量
	
	//标签体的主体方法
	@Override
	public int doStartTag() throws JspException {
		// TODO Auto-generated method stub
		//总页数
		int pageCount=(recordCount+pageSize-1)/pageSize;
		if(pageNo>pageCount){
			pageNo=pageCount;
		}
		if(pageNo<0){
			pageNo=1;
		}
		//提交到标签体的表单及脚本内容
		StringBuffer sb=new StringBuffer();
		sb.append("<div class=\"pagination\">");
		//当action=“”时，表示不刷新页面，只更新表单内容
		sb.append("<form action=\"\" method=\"post\" name=\"qPagerForm\">\r\n");
		//传递当前页码的隐式参数
		sb.append("<input type=\"hidden\" name=\"pageNo\" value=")
			.append(pageNo).append(">");
		//是否显示“上一页”链接
		if(pageNo>1){
			sb.append("<a href=\"javascript:void(null)\" onclick=\"turnOverPage("
					+ (pageNo-1) + ")\">");
			sb.append("pre");
			sb.append("</a>");
		}
		
		//是否显示当前页前面的"..."，以及其它前面的显示逻辑
		int start=1;
		if(pageNo>4){
			start=pageNo-1;
			sb.append("<a href=\"javascript:void(null)\" onclick=\"turnOverPage(1)\">");
			sb.append("1");
			sb.append("</a>");
			sb.append("<a href=\"javascript:void(null)\" onclick=\"turnOverPage(2)\">");
			sb.append("2");
			sb.append("</a>");
			sb.append("…");
		}
		int end=pageNo+1;
		if(end>pageCount){
			end=pageCount;
		}
		for(int i=start;i<=end;i++){
			if(i==pageNo){
				sb.append("<span class=\"current\">")
				  .append(pageNo)
				  .append("</span>");
			}else{
				sb.append("<a href=\"javascript:void(null)\" onclick=\"turnOverPage(")
					.append(i).append(")\">").append(i).append("</a>");
		
			}
		}
		//当前页面后面的显示逻辑
		if(end<pageCount-2){
			sb.append("…");
		}
		if(end<pageCount-1){
			sb.append("<a href=\"javascript:void(null)\" onclick=\"turnOverPage(")
				.append(pageCount-1).append(")\">").append(pageCount-1).append("</a>");
		}
		if(end<pageCount){
			sb.append("<a href=\"javascript:void(null)\" onclick=\"turnOverPage(")
			.append(pageCount).append(")\">").append(pageCount).append("</a>");
			//显示”下一页“链接2
			sb.append("<a href=\"javascript:void(null)\" onclick=\"turnOverPage(")
			.append(pageNo+1).append(")\">").append("next").append("</a>");
		}
		sb.append("</form></div>");
		
		//翻页脚本函数，主要作用：
		//（1）向TestPagerServlet提交跳转页码，更新条目内容的显示
		//（2）更新翻页标签的显示
		//脚本函数是隐式的，不会显示
		sb.append("<script language=\"javascript\">\r\n");
		sb.append("function turnOverPage(no){\r\n");
		//脚本与表单属于同一文档，下面是获取表单的方法
		sb.append("var qForm=document.qPagerForm;\r\n");
		sb.append("if(no>").append(pageCount)
			.append("){no=")
			.append(pageCount)
			.append(";}\r\n");
		sb.append("if(no<1){no=1;}\r\n");
		sb.append("qForm.pageNo.value=no;\r\n")
			.append("qForm.action=\"").append(url).append("\";");
		sb.append("qForm.submit();").append("\r\n}");
		sb.append("</script>");
		
		
		try {
			pageContext.getOut().println(sb.toString());
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
		return SKIP_BODY;
	}

	public void setRecordCount(int num){
		recordCount=num;
	}
	public void setPageNo(int num){
		pageNo=num;
	}
	public void setPageSize(int num){
		pageSize=num;
	}
	public void setUrl(String str){
		url=str;
	}
}

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class TestPagerTagServlet
 */
@WebServlet("/TestPagerTagServlet")
public class TestPagerTagServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
    private static final int PAGE_SIZE=10;
    private List<String> datas;
    /**
     * @see HttpServlet#HttpServlet()
     */
    public TestPagerTagServlet() {
        super();
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doPost(request, response);
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		int pageSize= PAGE_SIZE;
		request.setAttribute("pageSize", pageSize);
		int recordCount=datas.size();
		//获取当前页码
		String no=request.getParameter("pageNo");
		int pageNo=1;
		if(!"".equals(no) && no!=null){
			pageNo=Integer.parseInt(no);
		}
		request.setAttribute("recordCount",recordCount);
		request.setAttribute("pageNo", pageNo);
		
		int s=(pageNo-1)*pageSize;
		int e=s+pageSize;
		if(e>recordCount){
			e=recordCount;
		}
		List<String> subdatas=datas.subList(s, e);
		request.setAttribute("subdatas", subdatas);
		request.getRequestDispatcher("pager.jsp").forward(request, response);
	}

	@Override
	public void init() throws ServletException {
		// TODO Auto-generated method stub
		//super.init();
		//生成测试用的数据
		datas  = new ArrayList<String>();
		for(int i=1;i<105;i++){
			String str;
			str="String"+i;
			datas.add(str);
		}
	}

}

pager.tdl

<pre name="code" class="html"><?xml version="1.0" encoding="UTF-8"?>
<taglib>
  <tlib-version>0.0</tlib-version>
  <jsp-version>0.0</jsp-version>
  <short-name>q</short-name>
  <!--统一资源定位符，唯一即可-->
  <uri>http://www.csdn.net/cjc/tags/pagertag</uri>
  
  <!-- 自定义标签的描述信息 -->
	<tag>
		<!-- 标签名 -->
		<name>pager</name>
		<!-- 对应的标签处理类全限定名 -->
		<tag-class>mytags.PagerTag</tag-class>
		<!-- 标签主体的类型 -->
		<body-content>empty</body-content>
		<!-- 当前页号属性的描述信息 -->
		<attribute>
			<!-- 属性名 -->
			<name>pageNo</name>
			<!-- 该属性是否为必要的 -->
			<required>true</required>
			<!-- 属性值是否可以在JSP运行时期动态产生 -->
			<rtexprvalue>true</rtexprvalue>
			<!-- 属性的数据类型 -->
			<type>int</type>
		</attribute>
		<!-- 总记录数属性的描述信息 -->
		<attribute>
			<name>recordCount</name>
			<required>true</required>
			<rtexprvalue>true</rtexprvalue>
			<type>int</type>
		</attribute>
		<!-- 总页数属性的描述信息 -->
		<attribute>
			<name>pageSize</name>
			<required>true</required>
			<rtexprvalue>true</rtexprvalue>
			<type>int</type>
		</attribute>
		<!-- 分页标签要跳转的URI属性的描述信息 -->
		<attribute>
			<name>url</name>
			<required>true</required>
			<rtexprvalue>true</rtexprvalue>
			<type>java.lang.String</type>
		</attribute>
	</tag>
	
</taglib>

pager.jsp

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1" import ="java.util.*"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<%@ taglib uri="http://www.csdn.net/cjc/tags/pagertag" prefix="q" %>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>My Define Pager</title>

<style type="text/css">
.pagination{padding:5px; float:right;}
.pagination a, .pagination a:link, .pagination a:visted
{
	padding: 2px 5px 2px 5px;
    margin: 2px;
    border: 1px solid #aaaadd;
    text-decoration: none;
    color: #006699;
}
.pagination a:hover, .pagination a:active {
    border: 1px solid #ff0000;
    color: #000;
    text-decoration: none;
}
.pagination span.current {
    padding: 2px 5px 2px 5px;
    margin: 2px;
    border: 1px solid #ff0000;
    font-weight: bold;
    background-color: #ff0000;
    color: #FFF;
}
</style>

</head>
<body>

<table cellspacing="1" cellpadding="5" border="1" width="500" align="center">
	<% 
		out.println("<hr/>");
		List<String> datas = (List<String>)request.getAttribute("subdatas");
	
		for(int i=0;i<datas.size();i++){
			out.println("<tr><td>");
			out.println(datas.get(i));
			out.println("</td></tr>");
		}
	%>
</table>
	<!--EL表达式 -->
	<q:pager pageNo="${pageNo}"
			 pageSize="${pageSize}"
			 recordCount="${recordCount}"
			 url="TestPagerTagServlet" />

</body>
</html>

index.html

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<a href="TestPagerTagServlet">Test it now</a>
</body>
</html>

4、结果