Jsp servlet exception

Question

I've seen some similar answer to this question perhaps but I feel my situation is different. I'm developing a spring MVC app working great so far, that is I included hadoop api in my project, when I included hadoop this exception started happening when I am trying to open the initial dashboard page which worked previously :

java.lang.AbstractMethodError: javax.servlet.jsp.JspFactory.getJspApplicationContext(Ljavax/servlet/ 
ServletContext;)Ljavax/servlet/jsp/JspApplicationContext;
 org.apache.jsp.ServerInfo_jsp._jspInit(ServerInfo_jsp.java:63)
 org.apache.jasper.runtime.HttpJspBase.init(HttpJspBase.java:52)
 org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:158)
 org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:328)
 org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:336)
 org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
 javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
 org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:9

Here is how my hadoop dependency looks like :

<dependency>
            <groupId>org.apache.hadoop</groupId>
            <artifactId>hadoop-client</artifactId>
            <version>0.23.1-mr1-cdh4.0.0b2</version>
        </dependency>
        <dependency>
            <groupId>org.apache.hadoop</groupId>
            <artifactId>hadoop-core</artifactId>
            <version>0.23.1-mr1-cdh4.0.0b2</version>
            <exclusions>
                <exclusion>
                    <groupId>org.mortbay.jetty</groupId>
                    <artifactId>jetty</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>javax.servlet</groupId>
                    <artifactId>servlet-api</artifactId>
                </exclusion>
            </exclusions>
        </dependency>

Once I add this to my app it's no longer usable and naturally without these dependecies things run very smooth. What am I missing here?

Answer 1

I think that your problem is that hadoop is including a version of the servlet API which is coming before the "correct" servlet API in the classpath. Hadoop has dependencies on Jetty, and jetty will in turn try to include a servlet API.

I have a project with a very similar setup, Spring MVC and Hadoop. I have the below exclusions for the hadoop dependency. Note that this might vary slightly depending on your hadoop distribution, I am using cloudera's. Since the servlet container you are using will usually ship with its own javax.servlet dependency, your exclusion needs to catch this case. I have only tested the below configuration with Jetty:

           <dependency>     
              <groupId>org.apache.hadoop</groupId>
              <artifactId>hadoop-core</artifactId>
              <version>${hadoop.version}</version>
           <exclusions>

          <exclusion>
                <groupId>org.mortbay.jetty</groupId>
                <artifactId>jetty</artifactId>
            </exclusion>
            <exclusion>
                <groupId>org.mortbay.jetty</groupId>
                <artifactId>jetty-util</artifactId>
            </exclusion>
            <exclusion>
                <groupId>org.mortbay.jetty</groupId>
                <artifactId>jsp-2.1</artifactId>
            </exclusion>
            <exclusion>
                <groupId>org.mortbay.jetty</groupId>
                <artifactId>jsp-api-2.1</artifactId>
            </exclusion>
            <exclusion>
                <groupId>org.mortbay.jetty</groupId>
                <artifactId>servlet-api-2.1</artifactId>
            </exclusion>
            <exclusion>
                <groupId>javax.servlet</groupId>
                <artifactId>servlet-api</artifactId>
            </exclusion>
            <exclusion>
                <groupId>javax.servlet.jsp</groupId>
                <artifactId>jsp-api</artifactId>
            </exclusion>
            <exclusion>
                <groupId>tomcat</groupId>
                <artifactId>jasper-compiler</artifactId>
            </exclusion>
            <exclusion>
                <groupId>tomcat</groupId>
                <artifactId>jasper-runtime</artifactId>
            </exclusion>
            <!-- other exclusions snipped for brevity -->