JSP 사용자 정의 메소드 라이브러리

public class Function{
      public static int length(Object obj){  // 
             if(obj == null){
                    return 0;
             }
 
             if(obj instanceof StringBuffer){
                    return lenth(((StringBuffer)obj).toString());
             }
 
             if(obj instanceof String){
                    return ((String)obj).getBytes.length;
             }
 
             if(obj instanceof Collection){
                    return ((Collection)obj).size();
             }
      }
}

<?xml version="1.0" ecoding="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                 web-jsptaglibrary_2_0.xsd
      version="2.0">
 
      <description>custom functionslibrary</description>
      <display-name>customfunctions</display-name>
      <tlibversion>1.1</tlibversion>
      <shortname>function</shortname>
      <uri>http://www.clf.com/tags</uri>
 
 
      <function>
             <description>descriptioncontent </description>
             <name>lenth</name>
             <function-class>com.chen.Funtion</function-class>
             <function-signature>
                    int length(java.lang.Object)
             </function-signature>
             <example>
                    ${fn:length(string)}
             </example>
      <function>
 
</taglib>