如何创建自定义taglib

Question

我想制作一个util方法,从地图转换为列表,以便与EL一起使用,这是我试过的:

1- utils.taglib.xml:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE facelet-taglib PUBLIC
  "-//Sun Microsystems, Inc.//DTD Facelet Taglib 1.0//EN"
  "https://facelets.dev.java.net/source/browse/*checkout*/facelets/src/etc/facelet-taglib_1_0.dtd">
<facelet-taglib xmlns="http://java.sun.com/JSF/Facelet">
    <namespace>http://mycomp.com/utils</namespace>

    <function>
      <function-name>mapToList</function-name>
      <function-class>com.mycomp.MyClass</function-class>
      <function-signature>java.util.List mapToList(java.util.Map)</function-signature>
    </function>

</facelet-taglib>

2- web.xml:我添加了它,因为我添加了spring安全标记lib,如下所示:

<context-param>
    <param-name>javax.faces.FACELETS_LIBRARIES</param-name>
    <param-value>
    /WEB-INF/springsecurity.taglib.xml
    /WEB-INF/utils.taglib.xml
    </param-value>
</context-param>

3- xhtml页面:

xmlns:utils="http://mycomp.com/utils"

  <ui:repeat value="#{utils:mapToList(myBean.map)}" var="entry" >
    Key = #{entry.key} Value = #{entry.value} <br/>
  </ui:repeat>

4- Util类:

public class MyClass{

    public static <T, S> List<Map.Entry<T, S>> mapToList(Map<T, S> map) {

    if (map == null) {
        return null;
    }

    List<Map.Entry<T, S>> list = new ArrayList<Map.Entry<T, S>>();
    list.addAll(map.entrySet());

    return list;
  }

 }

问题:

我收到两个错误:

1-当试图打开使用弹簧安全标签的页面时,标签不再被识别,我收到错误:

Warning: This page calls for XML namespace http://www.springframework.org/security/tags declared with prefix sec but no taglibrary exists for that namespace.

2-当访问使用新自定义taglib的页面时,我收到错误:

Function 'utils:mapToList' not found 

请指教,谢谢.

Answer 1

在pount 2注释中,您必须通过将facelets.LIBRARIES作为以分号分隔的列表进行传递来定义要使用的多个标记库.

试试这个:

<context-param>
     <param-name>javax.faces.FACELETS_LIBRARIES</param-name>
     <param-value>/WEB-INF/springsecurity.taglib.xml;/WEB-INF/utils.taglib.xml</param-value>
</context-param>