Reusing custom JSP tags

Question

I would like to split my Spring/JSP/Maven/Tomcat webapp project to few different ones. So, each of them will act as a stand alone web application. Now, I want to use the same custom JSP tags in all the projects, but I don't want to copy the WEB-INF/tag folder everywhare. How can I have it defined in a shared project and reuse it in all dependent projects?

Answer 1

Further to the previous answer and assuming you are using Maven then your Common taglib project should look like:

-src
--main
---resources
-----META-INF
-----taglib.tld
-----tags
-------tag1.tag
-------tag2.tag

where the contents of your taglib.tld look like:

<?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 web-jsptaglibrary_2_0.xsd"
    version="2.0">

    <description>JSP 2.0 Tag File Library for Spring MVC and Bootstrap
    </description>
    <tlib-version>1.0</tlib-version>
    <short-name>my-taglib-name</short-name>
    <uri>http://my.taglib.namespace</uri>
    <tag-file>
        <name>tag1</name>
        <path>/META-INF/tags/tag1.tag</path>
    </tag-file>
    <tag-file>
        <name>tag2</name>
        <path>/META-INF/tags/tag2.tag</path>
    </tag-file>
</taglib>

and then you can just reference the taglib in dependant projects in the normal way.

<%@ taglib uri="http://my.taglib.namespace" prefix="t"%>

See documentation for further guidance:

http://docs.oracle.com/javaee/5/tutorial/doc/bnamu.html#bnana

Answer 2

I did this by putting the tld in the src/main/java/META-INF folder of the common project.

e.g. common.tld

<?xml version="1.0" encoding="ISO-8859-1" ?>

<!DOCTYPE taglib PUBLIC "-//Sun Microsystems, Inc.//DTD JSP Tag Library 1.1//EN" 
  "http://java.sun.com/j2ee/dtds/web-jsptaglibrary_1_1.dtd">

<taglib>
    <tlibversion>1.0</tlibversion>
    <jspversion>1.1</jspversion>
    <shortname>Custom common Tag Library</shortname>
    <uri>http://www.mysite.be/tags/common</uri>
    ...

Then it the JSP's in the project (that include the shared project):

<%@ taglib prefix="common" uri="http://www.mysite.be/tags/common" %>

Disclaimer: it's been a very long time ago since I did this so I hope I did not forget anything and not sure if this is (still) the best option.