SGF-92 - Improved error message in case no region can be found.

If the region referenced by an entity managed by a repository cannot be found in the application context we now throw an exception with an error message indicating the missing configuration.

src/main/java/org/springframework/data/gemfire/repository/support/GemfireRepositoryFactory.java

@@ -93,9 +93,14 @@ public class GemfireRepositoryFactory extends RepositoryFactorySupport {
 	private GemfireTemplate getTemplate(RepositoryMetadata metadata) {
 
 		Class<?> domainClass = metadata.getDomainType();
+		GemfirePersistentEntity<?> entity = context.getPersistentEntity(domainClass);
+
 		Region<?, ?> region = regions.getRegion(domainClass);
 
-		GemfirePersistentEntity<?> entity = context.getPersistentEntity(domainClass);
+		if (region == null) {
+			throw new IllegalStateException(String.format("No region '%s' found for domain class %s! Make sure you have "
+					+ "configured a Gemfire region of that name in your application context!", entity.getRegionName(), domainClass));
+		}
 
 		Class<?> regionKeyType = region.getAttributes().getKeyConstraint();
 		Class<?> entityIdType = metadata.getIdType();

src/test/java/org/springframework/data/gemfire/repository/support/GemfireRepositoryFactoryIntegrationTests.java

@@ -15,10 +15,13 @@
  */
 package org.springframework.data.gemfire.repository.support;
 
+import org.junit.Test;
 import org.springframework.data.gemfire.mapping.Regions;
 import org.springframework.data.gemfire.repository.sample.PersonRepository;
 import org.springframework.test.context.ContextConfiguration;
 
+import com.gemstone.bp.edu.emory.mathcs.backport.java.util.Collections;
+
 /**
  * Integration test for {@link GemfireRepositoryFactory}.
  * 
@@ -33,4 +36,12 @@ public class GemfireRepositoryFactoryIntegrationTests extends AbstractGemfireRep
 		GemfireRepositoryFactory factory = new GemfireRepositoryFactory(regions, null);
 		return factory.getRepository(PersonRepository.class);
 	}
+
+	@Test(expected = IllegalStateException.class)
+	@SuppressWarnings("unchecked")
+	public void throwsExceptionIfReferencedRegionIsNotConfigured() {
+
+		GemfireRepositoryFactory factory = new GemfireRepositoryFactory(Collections.emptySet(), null);
+		factory.getRepository(PersonRepository.class);
+	}
 }