OpenID4Java library offers support for OpenID-enabling a consumer site or implementing an OpenID Provider server.
'org.openid4java:openid4java-consumer-SampleConsumer:0.9.5'
<dependency>
<groupId>org.openid4java</groupId>
<artifactId>openid4java-consumer-SampleConsumer</artifactId>
<version>0.9.5</version>
</dependency>
<dependency org="org.openid4java" name="openid4java-consumer-SampleConsumer" rev="0.9.5"/>
"org.openid4java", "openid4java-consumer-SampleConsumer", "0.9.5"