实现的方法必须是静态的

<%...@ taglib uri="http://hxex.cn/vote" prefix="vote" %>
<c:forEach var="vote" items="${votes}">
<tr>
<td>${vote.name}</td>
<td>${vote.title}</td>
<td>${vote:votetype(vote.votetype)}</td>
<td>${vote:pictype(vote.pictype)}</td>
<td align="center">
<a href="vote_update.jsp?id=${vote.id}">修改投票</a>
<a href="<%=context %>/deleteVote.do?id=${vote.id}">删除投票</a>
<a href="voteitem_updatein.jsp?id=${vote.id}">修改选项</a>
</td>
</tr>
</c:forEach>


<?xml version="1.0" encoding="UTF-8" ?>

<taglib xmlns="http://java.sun.com/xml/ns/j2ee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-jsptaglibrary_2_0.xsd"
version="2.0">
<description>vote function library</description>
<display-name>Vote</display-name>
<tlib-version>1.0</tlib-version>
<short-name>vote</short-name>
<uri>http://hxex.cn/vote</uri>

<function>
<name>votetype</name>
<function-class>cn.hxex.vote.util.VoteFunction</function-class>
<function-signature>java.lang.String votetype(java.lang.String)</function-signature>
</function>

<function>
<name>pictype</name>
<function-class>cn.hxex.vote.util.VoteFunction</function-class>
<function-signature>java.lang.String pictype(java.lang.String)</function-signature>
</function>

<function>
<name>votetypeoptions</name>
<function-class>cn.hxex.vote.util.VoteFunction</function-class>
<function-signature>java.lang.String votetypeoptions(java.lang.String)</function-signature>
</function>

<function>
<name>pictypeoptions</name>
<function-class>cn.hxex.vote.util.VoteFunction</function-class>
<function-signature>java.lang.String pictypeoptions(java.lang.String)</function-signature>
</function>

</taglib>


package cn.hxex.vote.util;

public class VoteFunction ...{
public static String votetype(String votetype)...{

return SelectConst.getVoteTypeTitle(votetype);
}
public static String votetypeoptions(String defaultValue)...{
return SelectConst.getVoteTypeOptions(defaultValue);
}
public static String pictype(String pictype)...{
return SelectConst.getPicTypeTitle(pictype);
}
public static String pictypeoptions(String defaultValue)...{
return SelectConst.getPicTypeoptions(defaultValue);
}
}
http://blog.csdn.net/daryl715/archive/2007/02/11/1507387.aspx