Tomcat 7 and JSTL

Question

I wrote a web application with Eclipse Tomcat and it works on my local Tomcat 7, when I tried to publish it online on a Tomcat 7, I had the following error:

Answer 1

For Tomcat, there is a simpler dependency solution for JSTL 1.1.2:

<dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>jstl</artifactId>
    <!-- Apache Taglibs does not implement version 1.2 -->
    <version>1.1.2</version>
  </dependency>
  <dependency>
    <groupId>taglibs</groupId>
    <artifactId>standard</artifactId>
    <version>1.1.2</version>
    </dependency>
  <dependency>
    <groupId>taglibs</groupId>
    <artifactId>c</artifactId>
    <version>1.1.2</version>
    <type>tld</type>
  </dependency>
  <dependency>
    <groupId>taglibs</groupId>
    <artifactId>fmt</artifactId>
    <version>1.1.2</version>
    <type>tld</type>
  </dependency>
<dependency>

See here for more details (personal blog).

REM: More details as requested, one has to include JSTL dependencies to make them available on Tomcat. Yet, version 1.2 is not really necessary, since version 1.1.2 (delivered by Apache, like Tomcat) does the job too. Its only requirement is Servlet 2.4 and JSP 2.2, and the OP mention Servlet 3.0 and JSP 2.0, which is good enough.

Answer 2

The following dependencies in the pom.xml seem to resolve the issue:

<dependency>
    <groupId>org.glassfish.web</groupId>
    <artifactId>javax.servlet.jsp.jstl</artifactId>
    <version>1.2.1</version>
    <scope>provided</scope>
</dependency>

<dependency>
    <groupId>javax.servlet.jsp.jstl</groupId>
    <artifactId>javax.servlet.jsp.jstl-api</artifactId>
    <version>1.2.1</version>
    <scope>provided</scope>
</dependency>

That was a strange combination - two different groupIds - but it does work :). My expectation was to see the same group ID for both jars. I managed to redeploy without a problem to Tomcat 7.

Also, if you see "Unkown tag

Answer 3

I have been fighting with this for several hours. Here is a complete solution.

1. I am using Tomcat 7, which is a Servlet 3.0-compliant server.

2. If you desire to use the Servlet 3.0 spec, you must have your web.xml as follows:

   <web-app 
     xmlns="http://java.sun.com/xml/ns/javaee" 
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
     http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" version="3.0"> 
   

3. If you're using Maven, your pom.xml should have these lines.

   <dependency>
       <groupId>javax.servlet</groupId>
       <artifactId>javax.servlet-api</artifactId>
       <version>3.0.1</version>
       <scope>provided</scope>
   </dependency>
   
   <dependency>
       <groupId>javax.servlet</groupId>
       <artifactId>jstl</artifactId>
       <version>1.2</version>
   </dependency>
   
   <dependency>
       <groupId>org.glassfish.web</groupId>
       <artifactId>jstl-impl</artifactId>
       <version>1.2</version>
       <exclusions>
           <exclusion>
               <artifactId>servlet-api</artifactId>
               <groupId>javax.servlet</groupId>
           </exclusion>
           <exclusion>
               <artifactId>jsp-api</artifactId>
               <groupId>javax.servlet.jsp</groupId>
           </exclusion>
           <exclusion>
               <artifactId>jstl-api</artifactId>
               <groupId>javax.servlet.jsp.jstl</groupId>
           </exclusion>
       </exclusions>
   </dependency>
   

   These dependencies are very important. JSTL 2.1 + Tomcat 7 + Servlet 3.0 is very broken unless you fix it by using these lines, especially the exclusion part. What is happening is the JSTL 2.1 Jars are actually pulling in the wrong versions of the Servlet spec--2.5. Unless you stop that from happening, you will be in a whole world of pain. A special thanks to Mr. Murray Todd Williams for these insights .

4. Finally, in case Maven can't find those JARS, you can make Eclipse happy by including three JARS with your project and doing the usual Project--> Properties--> Java Build Path and include them that way--though Maven should take care of it.

   javax.servlet-api-3.0.1.jar
   javax.servlet.jsp.jstl-1.2.1.jar
   javax.servlet.jsp.jstl-api-1.2.1.jar
   

5. Please note! This exact configuration only applies if you are using the magic combination of:

   1. A Servlet 3.0-compliant application server such as Tomcat 7

   2. Your web.xml has the right namespace for the Servlet 3.0 spec

   3. You have those three JARS and no other JSTL or Servlet JARS on your classpath.

6. Make sure you do not place copies of these JARs in your WEB-INF/lib directory because they would in that case be sent to the server thereby causing LinkageErrors.

7. In your JSP, you need to have this PRECISE line, formatted exactly as I have it or else Eclipse will whine that it doesn't recognize the c:blah tags:

   <%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
   

8. What a danged PITA! This is MUCH harder to implement than any other version of JSTL. This is the only example of something getting much more complicated rather than simpler in later iterations.

Answer 4

There are two answers here that are mostly correct with regard to how to solve this problem when using Maven when dealing with this issue. However, both are not 100% complete.

Using Exclusions per @Tom Hunter's answer

This answer works. However, there will still be log messages from Tomcat regarding duplicate TLD definitions. This is because both the jstl and jstl-impl artifacts include the TLD definitions. To remove those messages, I think a better Maven setup is this:

<dependency>
    <version>1.2</version>
    <scope>runtime</scope>
    <groupId>javax.servlet.jsp.jstl</groupId>
    <artifactId>jstl-api</artifactId>
    <exclusions>
        <exclusion>
            <artifactId>servlet-api</artifactId>
            <groupId>javax.servlet</groupId>
        </exclusion>
        <exclusion>
            <artifactId>jsp-api</artifactId>
            <groupId>javax.servlet.jsp</groupId>
        </exclusion>
    </exclusions>
</dependency>

<dependency>
    <groupId>org.glassfish.web</groupId>
    <artifactId>jstl-impl</artifactId>
    <version>1.2</version>
    <scope>runtime</scope>
    <exclusions>
        <exclusion>
            <artifactId>servlet-api</artifactId>
            <groupId>javax.servlet</groupId>
        </exclusion>
        <exclusion>
            <artifactId>jsp-api</artifactId>
            <groupId>javax.servlet.jsp</groupId>
        </exclusion>
        <exclusion>
            <artifactId>jstl-api</artifactId>
            <groupId>javax.servlet.jsp.jstl</groupId>
        </exclusion>
    </exclusions>
</dependency>

This includes only the jstl api classes with the necessary exclusions to avoid the problems explained in the rest of that answer.

Using newer POM versions per @George's answer

It took me a while to realize it, but there are newer versions of the JSTL pom's available. It's really confusing because these newer packages use similar, but slightly different naming conventions. These newer versions mark the javax.servlet, javax.jsp, etc dependencies as provided scope so that they do not need to be excluded. The 1.2.1 version depends on a 1.2.1 version of the jstl-api. And so this would work as well as above answer:

<dependency>
    <groupId>org.glassfish.web</groupId>
    <artifactId>javax.servlet.jsp.jstl</artifactId>
    <version>1.2.1</version>
    <scope>runtime</scope>
</dependency>

This differs slightly from George's answer because I changed scope to runtime. George specified scope as provided. With a provided scope, the jars would have to be copied manually in to the Tomcat lib directory, or some other dependency would have to included the necessary implementation.

However, I could not find the 1.2.1 version of the impl in maven central, jboss repo, or any other repos. I ended up going around in circles and finally just used a local file based repo to store the jar. The dependency and jar are described here:

• http://mvnrepository.com/artifact/org.glassfish.web/javax.servlet.jsp.jstl/1.2.1

Answer 5

None of these worked for me, I simply created the project without using Maven and adding the JAR files directly.

Answer 6

For running on apache tomcat 7 adding these into your POM is probably appropriate. These jars don't reference javax.servlet jars like the glassfish ones do, so there is no need for exclusions.

<dependency>
    <groupId>org.apache.taglibs</groupId>
    <artifactId>taglibs-standard-spec</artifactId>
    <version>1.2.1</version>
</dependency>
<dependency>
    <groupId>org.apache.taglibs</groupId>
    <artifactId>taglibs-standard-impl</artifactId>
    <version>1.2.1</version>
</dependency>