创建自己的taglib 并打包入jar

1. Create a TLD (tag library descriptor) file namedmy-tags.tld. For more information, see Creating a Tag Library Descriptor.
例如：

<taglib>
    <display-name>Raptor JSP Taglib</display-name>
    <tlib-version>1.0</tlib-version>
    <jspversion>2.0</jspversion>
    <short-name>r</short-name>
    <uri>http://ebay.com/raptor</uri>
    <tag>
        <name>deferredFragment</name>
        <tagclass>com.ebay.raptor.fragment.jsp.DeferredFragmentTag</tagclass>
        <body-content>scriptless</body-content>
        <!--dynamic-attributes>true</dynamic-attributes-->
        <attribute>
            <name>afterRender</name>
            <type>String</type>
            <required>false</required>
            <rtexprvalue>false</rtexprvalue>
        </attribute>
        <attribute>
            <name>beforeRender</name>
            <type>String</type>
            <required>false</required>
            <rtexprvalue>false</rtexprvalue>
        </attribute>
        <attribute>
            <name>dependency</name>
            <type>Object</type>
            <required>false</required>
            <rtexprvalue>true</rtexprvalue>
        </attribute>
        <attribute>
            <name>fragmentDependencies</name>
            <type>String</type>
            <required>false</required>
            <rtexprvalue>true</rtexprvalue>
        </attribute>
        <attribute>
            <name>delay</name>
            <type>int</type>
            <required>false</required>
            <rtexprvalue>true</rtexprvalue>
        </attribute>
        <attribute>
            <name>timeoutFragment</name>
            <type>String</type>
            <required>false</required>
            <rtexprvalue>true</rtexprvalue>
        </attribute>
        <attribute>
            <name>timeoutURL</name>
            <type>String</type>
            <required>false</required>
            <rtexprvalue>true</rtexprvalue>
        </attribute>
        <attribute>
            <name>id</name>
            <type>String</type>
            <required>true</required>
            <rtexprvalue>true</rtexprvalue>
        </attribute>
        <attribute>
            <name>inline</name>
            <type>boolean</type>
            <required>false</required>
            <rtexprvalue>true</rtexprvalue>
        </attribute>
        <attribute>
            <name>outerElement</name>
            <type>String</type>
            <required>false</required>
            <rtexprvalue>true</rtexprvalue>
        </attribute>
        <attribute>
            <name>style</name>
            <type>String</type>
            <required>false</required>
            <rtexprvalue>true</rtexprvalue>
        </attribute>
        <attribute>
            <name>styleClass</name>
            <type>String</type>
            <required>false</required>
            <rtexprvalue>true</rtexprvalue>
        </attribute>
    </tag>
</taglib>

2. Create a directory containing the compiled Java tag handler class files used in your tag library.

3. Create a sub-directory of the directory you created in step 2 and call it META-INF.

注意my-tag.tld必须放在META-INF里，这也是web container回去search tld文件的位置

4. Copy the my-tags.tld file you created in step 1 into the META-INF directory you created in step 3

5. Archive your compiled Java class files into a jar file

6.Copy the jar file into the WEB-INF/lib directory of the Web application that uses your tag library.

有些文档说需要在web.xml 中提供对tag library 的引用才可以在JSP中使用，如下：

<taglib>
  <taglib-uri>myjar.tld</taglib-uri>
  <taglib-location>
     /WEB-INF/lib/myTagLibrary.jar
  </taglib-location>
</taglib>

但实际情况是，至少在Tomcat 和 Geronimo 服务器中，不需要上面的配置，服务器可以自己找到Jar里的tld文件，可能不同的服务器其实现不一样吧。

7.Reference the tag library in your JSP. For example:

<%@ taglib prefix="r" uri="http://ebay.com/raptor"%>

<r:includeRaptorJS />

参考：

http://docs.oracle.com/cd/E15051_01/wls/docs103/taglib/admin.html#wp364493

http://www.ibm.com/developerworks/cn/java/j-jsp07233/index.html