Supported Java EE 7 and 8 feature combinations

Some combinations of Java™ EE 8 and Java EE 7 Liberty features in a server configuration are compatible. However, many combinations are not compatible and cause an error when the server starts.

If a Java EE 7 Liberty feature was updated for Java EE 8, then the Java EE 7 version of the feature is not compatible with Java EE 8.

The error message resembles:

CWWKF0033E: The singleton features com.ibm.websphere.appserver.javaeeCompatible-7.0 and 
com.ibm.websphere.appserver.javaeeCompatible-8.0 cannot be loaded at the same time.  The configured 
features servlet-4.0 and jpa-2.1 include one or more features that cause the conflict. Your 
configuration is not supported.

The following table marks compatible feature combinations with a check mark (✔). Ensure that your server configuration does not contain incompatible features.

Table 1. Supported combinations of Java EE 8 and Java EE 7 Liberty features. New or updated Java EE 8 features are listed vertically. Java EE 7 features are listed horizontally. A check mark (✔) indicates that the combination of Java EE 8 and 7 features is supported and a server configuration can contain both features. An empty cell (no ✔) indicates that the combination of Java EE 8 and 7 features is not supported.
	Java EE 7 features
	batch-1.0	beanValidation-1.1	cdi-1.2	concurrent-1.0	el-3.0	ejb-3.2	ejbLite-3.2	javaMail-1.5	jacc-1.5	jaspic1.1	jaxrs-2.0	jca-1.7	jms-2.0	jpa-2.1	jsf-2.2	jsonp-1.0	jsp-2.3	mdb-3.2	servlet-3.1	websocket-1.1
Java EE 8 features
appSecurity-3.0	✔			✔	✔	✔	✔		✔	✔		✔	✔				✔	✔		✔
beanValidation-2.0	✔			✔	✔	✔	✔		✔	✔		✔	✔				✔	✔		✔
cdi-2.0	✔			✔	✔	✔	✔		✔	✔		✔	✔				✔	✔		✔
javaMail-1.6	✔			✔	✔	✔	✔		✔	✔		✔	✔				✔	✔		✔
jaxrs-2.1	✔			✔	✔	✔	✔		✔	✔		✔	✔				✔	✔		✔
jpa-2.2	✔			✔	✔	✔	✔		✔	✔		✔	✔				✔	✔		✔
jsf-2.3	✔			✔	✔	✔	✔		✔	✔		✔	✔				✔	✔		✔
jsonb-1.0	✔			✔	✔	✔	✔		✔	✔		✔	✔				✔	✔		✔
jsonp-1.1	✔			✔	✔	✔	✔		✔	✔		✔	✔				✔	✔		✔
servlet-4.0	✔			✔	✔	✔	✔		✔	✔		✔	✔				✔	✔		✔

The table shows that the servlet-3.1 feature of Java EE 7 is incompatible with the jaxrs-2.1 feature of Java EE 8. Thus, a server configuration with the following features causes an error:

<featureManager>
   <feature>servlet-3.0</feature>
   <feature>jaxrs-2.1</feature>
</featureManager>

To resolve the error, use servlet-4.0 instead of servlet-3.1 in the server configuration. The servlet-4.0 feature is compatible with the jaxrs-2.1 feature.

For more information on compatibility, or toleration, of features, see Tolerating features.