With the following code:

private Document transformDoc(Source source) throws TransformerException, IOException {
    Transformer xslTransformer =
            TransformerFactory.newInstance().newTransformer(new StreamSource(pdfTransformXslt.getInputStream()));
    xslTransformer.setParameter("http://apache.org/xml/features/nonvalidating/load-external-dtd", false);
    xslTransformer.setParameter("http://xml.org/sax/features/validation", false);
    JDOMResult result = new JDOMResult();
    xslTransformer.transform(source, result);
    return result.getDocument();
}

I'm getting the following error:

java.lang.AbstractMethodError: org.apache.xalan.processor.TransformerFactoryImpl.setFeature(Ljava/lang/String;Z)V

Why is this?

Here's my Maven dependency tree:

   ------------------------------------------------------------------------
   Building mc-hub-batch
      task-segment: [dependency:tree]
   ------------------------------------------------------------------------
   snapshot com.billmelater:mc-test-support:2.0.0.11-SNAPSHOT: checking for updates from repository.jboss.org
   [dependency:tree {execution: default-cli}]
   com.billmelater:mc-hub-batch:jar:2.0.0.11-SNAPSHOT
   +- com.billmelater:mc-hub-core:jar:2.0.0.11-SNAPSHOT:compile
   |  +- commons-lang:commons-lang:jar:2.4:compile
   |  +- commons-collections:commons-collections:jar:3.2.1:compile
   |  +- commons-beanutils:commons-beanutils:jar:1.8.0:compile
   |  +- commons-digester:commons-digester:jar:2.0:compile
   |  |  +- (commons-beanutils:commons-beanutils:jar:1.8.0:compile - omitted for duplicate)
   |  |  \- (commons-logging:commons-logging:jar:1.1.1:compile - version managed from 1.0.4; omitted for duplicate)
   |  \- (org.springframework.batch:spring-batch-core:jar:2.0.2.RELEASE:compile - omitted for duplicate)
   +- com.billmelater:mc-test-support:jar:2.0.0.11-SNAPSHOT:test
   |  +- (com.billmelater:mc-hub-core:jar:2.0.0.11-SNAPSHOT:test - omitted for duplicate)
   |  +- (org.springframework:spring:jar:2.5.6:test - omitted for duplicate)
   |  +- org.springframework:spring-jdbc:jar:2.5.6.SEC01:test
   |  |  +- (commons-logging:commons-logging:jar:1.1.1:test - omitted for duplicate)
   |  |  +- (org.springframework:spring-beans:jar:2.5.6.SEC01:test - omitted for conflict with 2.5.6)
   |  |  +- (org.springframework:spring-context:jar:2.5.6.SEC01:test - omitted for conflict with 2.5.6)
   |  |  +- (org.springframework:spring-core:jar:2.5.6.SEC01:test - omitted for conflict with 2.5.6)
   |  |  \- (org.springframework:spring-tx:jar:2.5.6.SEC01:test - omitted for conflict with 2.5.6)
   |  +- (org.dbunit:dbunit:jar:2.4.5:test - omitted for duplicate)
   |  +- (log4j:log4j:jar:1.2.15:test - omitted for duplicate)
   |  +- (org.slf4j:slf4j-api:jar:1.5.6:compile - version managed from 1.5.8; scope updated from test; omitted for duplicate)
   |  +- (org.slf4j:slf4j-log4j12:jar:1.5.6:test - omitted for duplicate)
   |  +- org.jboss.seam:jboss-seam:jar:2.2.0.GA:test
   |  |  +- xstream:xstream:jar:1.1.3:test
   |  |  +- (xpp3:xpp3_min:jar:1.1.3.4.O:compile - scope updated from test; omitted for duplicate)
   |  |  \- org.jboss.el:jboss-el:jar:1.0_02.CR4:test
   |  +- (org.testng:testng:jar:jdk15:5.8:test - omitted for duplicate)
   |  +- (org.hibernate:hibernate-core:jar:3.3.2.GA:test - version managed from 3.3.0.SP1; omitted for duplicate)
   |  +- org.hibernate:hibernate-entitymanager:jar:3.4.0.GA:test
   |  |  +- (org.hibernate:ejb3-persistence:jar:1.0.2.GA:test - omitted for duplicate)
   |  |  +- (org.hibernate:hibernate-commons-annotations:jar:3.1.0.GA:test - omitted for duplicate)
   |  |  +- (org.hibernate:hibernate-annotations:jar:3.4.0.GA:test - omitted for duplicate)
   |  |  +- (org.hibernate:hibernate-core:jar:3.3.2.GA:test - version managed from 3.3.0.SP1; omitted for duplicate)
   |  |  +- (org.slf4j:slf4j-api:jar:1.5.6:test - version managed from 1.4.2; omitted for duplicate)
   |  |  +- (dom4j:dom4j:jar:1.6.1-jboss:test - version managed from 1.6.1; omitted for duplicate)
   |  |  +- (javax.transaction:jta:jar:1.0.1B:test - version managed from 1.1; omitted for duplicate)
   |  |  \- javassist:javassist:jar:3.4.GA:test
   |  +- (org.hibernate:hibernate-validator:jar:3.1.0.GA:test - omitted for duplicate)
   |  +- (org.apache.velocity:velocity:jar:1.6.2:test - omitted for duplicate)
   |  \- (ojdbc:ojdbc:jar:14:test - omitted for duplicate)
   +- org.springframework:spring:jar:2.5.6:compile
   +- org.springframework.batch:spring-batch-core:jar:2.0.2.RELEASE:compile
   |  +- org.springframework.batch:spring-batch-infrastructure:jar:2.0.2.RELEASE:compile
   |  |  +- (commons-logging:commons-logging:jar:1.1.1:compile - omitted for duplicate)
   |  |  +- (org.springframework:spring-core:jar:2.5.6:compile - omitted for duplicate)
   |  |  \- (stax:stax:jar:1.2.0:compile - omitted for duplicate)
   |  +- org.aspectj:aspectjrt:jar:1.5.4:compile
   |  +- org.aspectj:aspectjweaver:jar:1.5.4:compile
   |  +- com.thoughtworks.xstream:xstream:jar:1.3:compile
   |  |  \- xpp3:xpp3_min:jar:1.1.4c:compile
   |  +- org.codehaus.jettison:jettison:jar:1.0:compile
   |  +- org.springframework:spring-aop:jar:2.5.6:compile
   |  |  +- aopalliance:aopalliance:jar:1.0:compile
   |  |  +- (commons-logging:commons-logging:jar:1.1.1:compile - omitted for duplicate)
   |  |  +- (org.springframework:spring-beans:jar:2.5.6:compile - omitted for duplicate)
   |  |  \- (org.springframework:spring-core:jar:2.5.6:compile - omitted for duplicate)
   |  +- org.springframework:spring-beans:jar:2.5.6:compile
   |  |  +- (commons-logging:commons-logging:jar:1.1.1:compile - omitted for duplicate)
   |  |  \- (org.springframework:spring-core:jar:2.5.6:compile - omitted for duplicate)
   |  +- org.springframework:spring-context:jar:2.5.6:compile
   |  |  +- (aopalliance:aopalliance:jar:1.0:compile - omitted for duplicate)
   |  |  +- (commons-logging:commons-logging:jar:1.1.1:compile - omitted for duplicate)
   |  |  +- (org.springframework:spring-beans:jar:2.5.6:compile - omitted for duplicate)
   |  |  \- (org.springframework:spring-core:jar:2.5.6:compile - omitted for duplicate)
   |  +- org.springframework:spring-core:jar:2.5.6:compile
   |  |  \- (commons-logging:commons-logging:jar:1.1.1:compile - omitted for duplicate)
   |  +- org.springframework:spring-tx:jar:2.5.6:compile
   |  |  +- (commons-logging:commons-logging:jar:1.1.1:compile - omitted for duplicate)
   |  |  +- (org.springframework:spring-beans:jar:2.5.6:compile - omitted for duplicate)
   |  |  +- (org.springframework:spring-context:jar:2.5.6:compile - omitted for duplicate)
   |  |  \- (org.springframework:spring-core:jar:2.5.6:compile - omitted for duplicate)
   |  \- stax:stax:jar:1.2.0:compile
   |     \- stax:stax-api:jar:1.0.1:compile
   +- commons-dbcp:commons-dbcp:jar:1.2.2:compile
   |  \- commons-pool:commons-pool:jar:1.3:compile
   +- org.hibernate:hibernate-core:jar:3.3.2.GA:compile
   |  +- antlr:antlr:jar:2.7.7:compile (version managed from 2.7.6)
   |  +- dom4j:dom4j:jar:1.6.1-jboss:compile (version managed from 1.6.1)
   |  +- javax.transaction:jta:jar:1.0.1B:compile (version managed from 1.1)
   |  \- (org.slf4j:slf4j-api:jar:1.5.6:compile - version managed from 1.4.2; omitted for duplicate)
   +- org.hibernate:hibernate-validator:jar:3.1.0.GA:compile
   |  +- (org.hibernate:hibernate-core:jar:3.3.2.GA:compile - version managed from 3.3.0.SP1; omitted for duplicate)
   |  +- org.hibernate:hibernate-commons-annotations:jar:3.1.0.GA:compile
   |  |  \- (org.slf4j:slf4j-api:jar:1.5.6:compile - version managed from 1.4.2; omitted for duplicate)
   |  \- (org.slf4j:slf4j-api:jar:1.5.6:compile - version managed from 1.4.2; omitted for duplicate)
   +- org.hibernate:hibernate-annotations:jar:3.4.0.GA:compile
   |  +- org.hibernate:ejb3-persistence:jar:1.0.2.GA:compile
   |  +- (org.hibernate:hibernate-commons-annotations:jar:3.1.0.GA:compile - omitted for duplicate)
   |  +- (org.hibernate:hibernate-core:jar:3.3.2.GA:compile - version managed from 3.3.0.SP1; omitted for duplicate)
   |  +- (org.slf4j:slf4j-api:jar:1.5.6:compile - version managed from 1.4.2; omitted for duplicate)
   |  \- (dom4j:dom4j:jar:1.6.1-jboss:compile - version managed from 1.6.1; omitted for duplicate)
   +- ojdbc:ojdbc:jar:14:compile
   +- org.slf4j:slf4j-api:jar:1.5.6:compile
   +- org.slf4j:slf4j-log4j12:jar:1.5.6:compile
   |  \- (org.slf4j:slf4j-api:jar:1.5.6:compile - version managed from 1.4.2; omitted for duplicate)
   +- log4j:log4j:jar:1.2.15:compile
   +- org.apache.velocity:velocity:jar:1.6.2:compile
   |  +- (commons-collections:commons-collections:jar:3.2.1:compile - omitted for duplicate)
   |  +- (commons-lang:commons-lang:jar:2.4:compile - omitted for duplicate)
   |  \- oro:oro:jar:2.0.8:compile
   +- org.testng:testng:jar:jdk15:5.8:test
   +- org.dbunit:dbunit:jar:2.4.5:test
   |  +- junit:junit:jar:4.7:test (version managed from 3.8.2)
   |  +- (org.slf4j:slf4j-api:jar:1.5.6:test - version managed from 1.4.2; omitted for duplicate)
   |  \- (commons-collections:commons-collections:jar:3.2.1:test - omitted for duplicate)
   +- hsqldb:hsqldb:jar:1.8.0.7:test
   +- jboss:javassist:jar:3.3.ga:provided
   +- org.jdom:jdom:jar:1.1:compile
   +- jaxen:jaxen:jar:1.1.1:provided
   +- org.apache.xmlgraphics:fop:jar:0.95:compile
   |  +- (org.apache.xmlgraphics:xmlgraphics-commons:jar:1.3.1:compile - omitted for duplicate)
   |  +- org.apache.xmlgraphics:batik-svg-dom:jar:1.7:compile
   |  |  +- (org.apache.xmlgraphics:batik-svg-dom:jar:1.7:compile - omitted for cycle)
   |  |  +- org.apache.xmlgraphics:batik-anim:jar:1.7:compile
   |  |  |  +- (org.apache.xmlgraphics:batik-awt-util:jar:1.7:compile - omitted for duplicate)
   |  |  |  +- (org.apache.xmlgraphics:batik-dom:jar:1.7:compile - omitted for duplicate)
   |  |  |  +- (org.apache.xmlgraphics:batik-ext:jar:1.7:compile - omitted for duplicate)
   |  |  |  \- (org.apache.xmlgraphics:batik-parser:jar:1.7:compile - omitted for duplicate)
   |  |  +- (org.apache.xmlgraphics:batik-awt-util:jar:1.7:compile - omitted for duplicate)
   |  |  +- org.apache.xmlgraphics:batik-css:jar:1.7:compile
   |  |  |  +- (org.apache.xmlgraphics:batik-ext:jar:1.7:compile - omitted for duplicate)
   |  |  |  +- (org.apache.xmlgraphics:batik-util:jar:1.7:compile - omitted for duplicate)
   |  |  |  \- (xml-apis:xml-apis-ext:jar:1.3.04:compile - omitted for duplicate)
   |  |  +- org.apache.xmlgraphics:batik-dom:jar:1.7:compile
   |  |  |  +- (org.apache.xmlgraphics:batik-css:jar:1.7:compile - omitted for duplicate)
   |  |  |  +- (org.apache.xmlgraphics:batik-ext:jar:1.7:compile - omitted for duplicate)
   |  |  |  +- (org.apache.xmlgraphics:batik-util:jar:1.7:compile - omitted for duplicate)
   |  |  |  +- (org.apache.xmlgraphics:batik-xml:jar:1.7:compile - omitted for duplicate)
   |  |  |  +- (xalan:xalan:jar:2.6.0:compile - omitted for duplicate)
   |  |  |  \- (xml-apis:xml-apis-ext:jar:1.3.04:compile - omitted for duplicate)
   |  |  +- (org.apache.xmlgraphics:batik-ext:jar:1.7:compile - omitted for duplicate)
   |  |  +- org.apache.xmlgraphics:batik-parser:jar:1.7:compile
   |  |  |  +- (org.apache.xmlgraphics:batik-awt-util:jar:1.7:compile - omitted for duplicate)
   |  |  |  +- (org.apache.xmlgraphics:batik-util:jar:1.7:compile - omitted for duplicate)
   |  |  |  \- (org.apache.xmlgraphics:batik-xml:jar:1.7:compile - omitted for duplicate)
   |  |  +- org.apache.xmlgraphics:batik-util:jar:1.7:compile
   |  |  \- xml-apis:xml-apis-ext:jar:1.3.04:compile
   |  +- org.apache.xmlgraphics:batik-bridge:jar:1.7:compile
   |  |  +- (org.apache.xmlgraphics:batik-anim:jar:1.7:compile - omitted for duplicate)
   |  |  +- (org.apache.xmlgraphics:batik-awt-util:jar:1.7:compile - omitted for duplicate)
   |  |  +- (org.apache.xmlgraphics:batik-css:jar:1.7:compile - omitted for duplicate)
   |  |  +- (org.apache.xmlgraphics:batik-dom:jar:1.7:compile - omitted for duplicate)
   |  |  +- (org.apache.xmlgraphics:batik-ext:jar:1.7:compile - omitted for duplicate)
   |  |  +- (org.apache.xmlgraphics:batik-bridge:jar:1.7:compile - omitted for cycle)
   |  |  +- (org.apache.xmlgraphics:batik-gvt:jar:1.7:compile - omitted for duplicate)
   |  |  +- (org.apache.xmlgraphics:batik-parser:jar:1.7:compile - omitted for duplicate)
   |  |  +- (org.apache.xmlgraphics:batik-bridge:jar:1.7:compile - omitted for cycle)
   |  |  +- org.apache.xmlgraphics:batik-script:jar:1.7:compile
   |  |  +- (org.apache.xmlgraphics:batik-svg-dom:jar:1.7:compile - omitted for duplicate)
   |  |  +- (org.apache.xmlgraphics:batik-util:jar:1.7:compile - omitted for duplicate)
   |  |  +- org.apache.xmlgraphics:batik-xml:jar:1.7:compile
   |  |  |  \- (org.apache.xmlgraphics:batik-util:jar:1.7:compile - omitted for duplicate)
   |  |  +- xalan:xalan:jar:2.6.0:compile
   |  |  \- (xml-apis:xml-apis-ext:jar:1.3.04:compile - omitted for duplicate)
   |  +- org.apache.xmlgraphics:batik-awt-util:jar:1.7:compile
   |  |  \- (org.apache.xmlgraphics:batik-util:jar:1.7:compile - omitted for duplicate)
   |  +- org.apache.xmlgraphics:batik-gvt:jar:1.7:compile
   |  |  +- (org.apache.xmlgraphics:batik-awt-util:jar:1.7:compile - omitted for duplicate)
   |  |  +- (org.apache.xmlgraphics:batik-gvt:jar:1.7:compile - omitted for cycle)
   |  |  +- (org.apache.xmlgraphics:batik-bridge:jar:1.7:compile - omitted for duplicate)
   |  |  \- (org.apache.xmlgraphics:batik-util:jar:1.7:compile - omitted for duplicate)
   |  +- org.apache.xmlgraphics:batik-transcoder:jar:1.7:compile
   |  |  +- (org.apache.xmlgraphics:batik-awt-util:jar:1.7:compile - omitted for duplicate)
   |  |  +- (org.apache.xmlgraphics:batik-bridge:jar:1.7:compile - omitted for duplicate)
   |  |  +- (org.apache.xmlgraphics:batik-dom:jar:1.7:compile - omitted for duplicate)
   |  |  +- (org.apache.xmlgraphics:batik-gvt:jar:1.7:compile - omitted for duplicate)
   |  |  +- (org.apache.xmlgraphics:batik-svg-dom:jar:1.7:compile - omitted for duplicate)
   |  |  +- org.apache.xmlgraphics:batik-svggen:jar:1.7:compile
   |  |  |  +- (org.apache.xmlgraphics:batik-awt-util:jar:1.7:compile - omitted for duplicate)
   |  |  |  \- (org.apache.xmlgraphics:batik-util:jar:1.7:compile - omitted for duplicate)
   |  |  +- (org.apache.xmlgraphics:batik-util:jar:1.7:compile - omitted for duplicate)
   |  |  +- (org.apache.xmlgraphics:batik-xml:jar:1.7:compile - omitted for duplicate)
   |  |  \- (xml-apis:xml-apis-ext:jar:1.3.04:compile - omitted for duplicate)
   |  +- org.apache.xmlgraphics:batik-extension:jar:1.7:compile
   |  |  +- (org.apache.xmlgraphics:batik-awt-util:jar:1.7:compile - omitted for duplicate)
   |  |  +- (org.apache.xmlgraphics:batik-bridge:jar:1.7:compile - omitted for duplicate)
   |  |  +- (org.apache.xmlgraphics:batik-css:jar:1.7:compile - omitted for duplicate)
   |  |  +- (org.apache.xmlgraphics:batik-dom:jar:1.7:compile - omitted for duplicate)
   |  |  +- (org.apache.xmlgraphics:batik-ext:jar:1.7:compile - omitted for duplicate)
   |  |  +- (org.apache.xmlgraphics:batik-gvt:jar:1.7:compile - omitted for duplicate)
   |  |  +- (org.apache.xmlgraphics:batik-parser:jar:1.7:compile - omitted for duplicate)
   |  |  +- (org.apache.xmlgraphics:batik-svg-dom:jar:1.7:compile - omitted for duplicate)
   |  |  +- (org.apache.xmlgraphics:batik-util:jar:1.7:compile - omitted for duplicate)
   |  |  \- (xml-apis:xml-apis-ext:jar:1.3.04:compile - omitted for duplicate)
   |  +- org.apache.xmlgraphics:batik-ext:jar:1.7:compile
   |  +- commons-logging:commons-logging:jar:1.1.1:compile
   |  +- commons-io:commons-io:jar:1.3.1:compile
   |  \- org.apache.avalon.framework:avalon-framework-api:jar:4.3.1:compile
   +- org.apache.xmlgraphics:xmlgraphics-commons:jar:1.3.1:compile
   |  +- (commons-io:commons-io:jar:1.3.1:compile - omitted for duplicate)
   |  \- (commons-logging:commons-logging:jar:1.1.1:compile - version managed from 1.0.4; omitted for duplicate)
   +- org.easymock:easymock:jar:2.0:test
   \- org.easymock:easymockclassextension:jar:2.2:test
      +- (org.easymock:easymock:jar:2.2:test - omitted for conflict with 2.0)
      \- cglib:cglib-nodep:jar:2.2:test (version managed from 2.1_3)

Can anyone tell me how to clear out intellij's classpath too?