Java Synchronization issues in URLSchemaContextResolver

There are some synchronization issues in the URLSchemaContextResolver class, specifically visibility issues. Specifically:

The currentSchemaContext variable in this class is not thread safe. The "tryToUpdateSchemaContext" method is synchronized, but other places where we read the variable are not synchronized. This leads to "visibility" issues where an update to the variable may not be immediately visible in other threads.

To fix this, we need to either make the variable currentSchemaContext volatile, or ensure that all access to it is synchronized. This can lead to indeterminate behavior.