Upgrading to com.networknt:json-schema-validator v2.0.0 breaks MockServer

[peter-thomas-mgd]

Describe the issue
We have a Gradle project that has been using the MockServer Java client and server for a number of years in our unit tests. The project is in active development and we perform monthly maintenance to upgrade all dependencies to their latest versions.

The project has a dependency on com.networknt:json-schema-validator in its main code. When we upgraded json-schema-validator to version 2.0.0 and fixed the breaking changes in our main application, MockServer started failing with runtime errors in our tests. The main issue seems to be a change in the package namespaces and interfaces used by json-schema-validator .

What you are trying to do
In our Gradle configuration, we have the following dependencies:

implementation("com.networknt:json-schema-validator:2.0.0")
...
testImplementation("org.mock-server:mockserver-netty:5.15.0")

This configuration has worked in multiple previous versions of json-schema-validator up to version 1.5.9. But after the update to version 2.0.0 our tests fail with the following error:

java.lang.NoClassDefFoundError: com/networknt/schema/SpecVersion$VersionFlag
	at org.mockserver.validator.jsonschema.JsonSchemaValidator.<clinit>(JsonSchemaValidator.java:39) ~[mockserver-core-5.15.0.jar:5.15.0]
	at org.mockserver.serialization.ExpectationSerializer.getValidator(ExpectationSerializer.java:67) ~[mockserver-core-5.15.0.jar:5.15.0]
	at org.mockserver.serialization.ExpectationSerializer.deserialize(ExpectationSerializer.java:127) ~[mockserver-core-5.15.0.jar:5.15.0]
	at org.mockserver.serialization.ExpectationSerializer.deserializeArray(ExpectationSerializer.java:195) ~[mockserver-core-5.15.0.jar:5.15.0]
	at org.mockserver.serialization.ExpectationSerializer.deserializeArray(ExpectationSerializer.java:158) ~[mockserver-core-5.15.0.jar:5.15.0]
	at org.mockserver.mock.HttpState.handle(HttpState.java:600) ~[mockserver-core-5.15.0.jar:5.15.0]
	at org.mockserver.netty.HttpRequestHandler.channelRead0(HttpRequestHandler.java:114) ~[mockserver-netty-5.15.0.jar:5.15.0]
	at org.mockserver.netty.HttpRequestHandler.channelRead0(HttpRequestHandler.java:51) ~[mockserver-netty-5.15.0.jar:5.15.0]

This looks like it is happening because of a transient dependency on com.networknt:json-schema-validator:1.0.76 in the org.mock-server library.

If we switch our Gradle dependencies to use the shaded MockServer jar, as in the following:

implementation("com.networknt:json-schema-validator:2.0.0")
...
testImplementation("org.mock-server:mockserver-netty-no-dependencies:5.15.0")

we get a different error:

java.util.MissingResourceException: Can't find resource for bundle java.util.PropertyResourceBundle, key crossEdits
	at java.base/java.util.ResourceBundle.getObject(ResourceBundle.java:558)
	at java.base/java.util.ResourceBundle.getObject(ResourceBundle.java:552)
	at java.base/java.util.ResourceBundle.getString(ResourceBundle.java:514)
	at shaded_package.com.networknt.schema.I18nSupport.getString(I18nSupport.java:33)
	at shaded_package.com.networknt.schema.ValidatorTypeCode.<clinit>(ValidatorTypeCode.java:54)
	at shaded_package.com.networknt.schema.Version7.getInstance(Version7.java:18)
	at shaded_package.com.networknt.schema.JsonSchemaFactory.getInstance(JsonSchemaFactory.java:244)
	at org.mockserver.validator.jsonschema.JsonSchemaValidator.getJsonSchemaFactory(JsonSchemaValidator.java:90)

If we revert json-schema-validator to version 1.5.9 in the Gradle dependencies, the first configuration with mockserver-netty works correctly, but the shaded library configuration using mockserver-netty-no-dependencies still throws the resource bundle exception.

MockServer version
MockServer 5.15.0
Java 25.0.1
Gradle 9.2.1

To Reproduce
See explanation above.