Running 'mvn compile' causes the following compilation errors in the encoder-esapi artifact (aka, ESAPI Thunk) when used with esapi-2.2.0.0-rc2.jar:
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.5.1:compile (default-compile) on project encoder-esapi: Compilation failure
[ERROR] /home/kww/Code/GitHub/owasp-java-encoder/esapi/src/main/java/org/owasp/encoder/esapi/ESAPIEncoder.java:[128,13] org.owasp.encoder.esapi.ESAPIEncoder.Impl is not abstract and does not override abstract method getCanonicalizedURI(java.net.URI) in org.owasp.esapi.Encoder
Note that this problem was described as part of your GitHub issue #30 but is not related to that. It was the serendipitous discovery caused by the non-pinned ESAPI transitive dependency that allowed this issue to be discovered.
If you want to eventually be able to support ESAPI 2.2.0.0 this will need to be fixed.