Configuring Liberty for Expression Language 3.0
You can configure Liberty for the Expression Language (EL) 3.0 feature, which provides full support for the EL 3.0 specification.
About this task
To configure a Liberty server to run an
application that is enabled for EL 3.0, you must set the <el-3.0> feature.
Procedure
Update the
server.xml file to add the <el-3.0>
feature. For example:
<featureManager>
<feature>el-3.0</feature>
</featureManager>Important:
- The EL 3.0 feature does not require any additional features. You can configure it independently of JavaServer Pages (JSP) 2.3.
- The JSP 2.3 feature requires the EL 3.0 feature. When you configure the JSP 2.3 feature, the EL 3.0 feature also loads into the server run time.
- You can use other Java™ EE 6 features, such as JSF 2.0 and CDI 1.0, with the EL 3.0 feature.
- You can choose between EL 3.0 and EL 2.2 (included in the JSP 2.2 feature) for each server instance, but you must consider any behavior changes. If the required behavior is contained only in the EL 3.0 feature, then you must use the EL 3.0 feature. If an existing application would be adversely affected by behavior changes in the EL 3.0 feature, then use the EL 2.2 feature (included in JSP 2.2) to preserve the existing behavior for that application.
- It is not possible to use both the EL 3.0 feature and JSP 2.2 (includes EL 2.2) features in the
same Liberty server. If both features are
configured, it produces an
error:
CWWKF0033E: The singleton features com.ibm.websphere.appserver.javax.el-2.2 and com.ibm.websphere.appserver.javax.el-3.0 cannot be loaded at the same time. The configured features jsp-2.2 and el-3.0 include one or more features that cause the conflict.
See Expression Language 3.0 feature functions to learn about changes in the EL 3.0 feature, compared to the EL 2.2 feature.