Refactor the ResourceResolver interface, require(..) method to throw a ResourceNotFoundException.

Edit Javadoc.

Resolves gh-92.

spring-geode/src/main/java/org/springframework/geode/core/io/ResourceResolver.java

@@ -15,8 +15,6 @@
  */
 package org.springframework.geode.core.io;
 
-import static org.springframework.data.gemfire.util.RuntimeExceptionFactory.newIllegalStateException;
-
 import java.util.Optional;
 
 import org.springframework.core.io.Resource;
@@ -27,6 +25,7 @@ import org.springframework.util.ClassUtils;
  * Interface defining a contract encapsulating an algorithm/strategy for resolving {@link Resource Resources}.
  *
  * @author John Blum
+ * @see java.lang.FunctionalInterface
  * @see org.springframework.core.io.Resource
  * @since 1.3.1.
  */
@@ -68,9 +67,9 @@ public interface ResourceResolver {
 	 *
 	 * @param location {@link String location} identifying the {@link Resource} to resolve;
 	 * must not be {@literal null}.
-	 * @return a {@literal non-null}, {@literal existing} {@link Resource} handle for the resolved
-	 * {@link String location}.
-	 * @throws IllegalStateException if a {@link Resource} cannot be resolved from the given {@link String location}.
+	 * @return a {@literal non-null}, {@literal existing} {@link Resource} handle for
+	 * the resolved {@link String location}.
+	 * @throws ResourceNotFoundException if a {@link Resource} cannot be resolved from the given {@link String location}.
 	 * A {@link Resource} is unresolvable if the given {@link String location} does not exist (physically);
 	 * see {@link Resource#exists()}.
 	 * @see org.springframework.core.io.Resource
@@ -79,6 +78,6 @@ public interface ResourceResolver {
 	default @NonNull Resource require(@NonNull String location) {
 		return resolve(location)
 			.filter(Resource::exists)
-			.orElseThrow(() -> newIllegalStateException("Resource [%s] does not exist", location));
+			.orElseThrow(() -> new ResourceNotFoundException(String.format("Resource [%s] does not exist", location)));
 	}
 }

spring-geode/src/test/java/org/springframework/geode/core/io/ResourceResolverUnitTests.java

@@ -23,6 +23,7 @@ import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.verifyNoMoreInteractions;
 
 import java.util.Optional;
 import java.util.Set;
@@ -78,10 +79,11 @@ public class ResourceResolverUnitTests {
 
 		verify(resourceResolver, times(1)).resolve(eq(location));
 		verify(mockResource, times(1)).exists();
+		verifyNoMoreInteractions(mockResource);
 	}
 
-	@Test(expected = IllegalStateException.class)
-	public void requireCallsResolveReturningNonExistingResourceThrowsIllegalStateException() {
+	@Test(expected = ResourceNotFoundException.class)
+	public void requireCallsResolveReturningNonExistingResourceThrowsResourceNotFoundException() {
 
 		String location = "/path/to/non-existing/resource.dat";
 
@@ -96,7 +98,7 @@ public class ResourceResolverUnitTests {
 		try {
 			resourceResolver.require(location);
 		}
-		catch (IllegalStateException expected) {
+		catch (ResourceNotFoundException expected) {
 
 			assertThat(expected).hasMessage("Resource [%s] does not exist", location);
 			assertThat(expected).hasNoCause();
@@ -106,23 +108,24 @@ public class ResourceResolverUnitTests {
 		finally {
 			verify(resourceResolver, times(1)).resolve(eq(location));
 			verify(mockResource, times(1)).exists();
+			verifyNoMoreInteractions(mockResource);
 		}
 	}
 
-	@Test(expected = IllegalStateException.class)
-	public void requireCallsResolveReturningNoResourceThrowsIllegalStateException() {
+	@Test(expected = ResourceNotFoundException.class)
+	public void requireCallsResolveReturningNoResourceThrowsResourceNotFoundException() {
 
 		String location = "/path/to/nowhere";
 
 		ResourceResolver resourceResolver = mock(ResourceResolver.class);
 
-		doReturn(Optional.empty()).when(resourceResolver).resolve(eq(location));
+		doReturn(Optional.empty()).when(resourceResolver).resolve(any());
 		doCallRealMethod().when(resourceResolver).require(any());
 
 		try {
 			resourceResolver.require(location);
 		}
-		catch (IllegalStateException expected) {
+		catch (ResourceNotFoundException expected) {
 
 			assertThat(expected).hasMessage("Resource [%s] does not exist", location);
 			assertThat(expected).hasNoCause();