Configuring Liberty for Servlet 4.0
You can configure Liberty for the Servlet 4.0 feature, which provides full support for the Servlet 4.0 specification.
About this task
To configure a Liberty server to run an
application that is enabled for Servlet 4.0, add the servlet-4.0
feature.
Procedure
Update the
server.xml
file to add the servlet-4.0
feature as
shown in the following example:
<featureManager>
<feature>servlet-4.0</feature>
</featureManager>
- The Servlet 4.0 feature can be used only with other Java™
EE 8 features and Java EE 7 features that do not have an
equivalent Java EE 8 version. For example, you can use the
jsf-2.3
feature only with Servlet 4.0, but you can use thejsp-2.3
feature with either Servlet 4.0 or Servlet 3.1. - The following list includes other features that require or tolerate Servlet 4.0:
- The Java EE 7 feature
jsp-2.3
- The Java EE 7 feature
websocket-1.1
- The Java EE 7 feature
- You can choose between Servlet 3.0, Servlet 3.1, and Servlet 4.0 feature implementations for each server instance. However, consider behavior changes. If only the Servlet 4.0 feature contains a required behavior, use the Servlet 4.0 feature.
- If behavior changes in the Servlet 4.0 feature adversely impact an existing application, use either the Servlet 3.1 feature or the Servlet 3.0 feature to preserve the existing behavior for that application.
- You cannot use two servlet features in the same Liberty server. If two or more servlet features are configured, either directly or indirectly through other features, the program produces an error. For more information, see Servlet 4.0 behavior changes.
- The Servlet 4.0 feature requires Java 8 at minimum.