DATAGEODE-317 - Add PoolResolver implementation that resolves a single, configured Pool.

spring-data-geode/src/main/java/org/springframework/data/gemfire/client/support/SinglePoolPoolResolver.java

@@ -0,0 +1,78 @@
+/*
+ * Copyright 2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.gemfire.client.support;
+
+import org.apache.geode.cache.client.Pool;
+
+import org.springframework.data.gemfire.client.PoolResolver;
+import org.springframework.lang.NonNull;
+import org.springframework.lang.Nullable;
+import org.springframework.util.Assert;
+
+/**
+ * {@link PoolResolver} implementation that resolves a single, configured {@link Pool}.
+ *
+ * @author John Blum
+ * @see org.apache.geode.cache.client.Pool
+ * @see org.springframework.data.gemfire.client.PoolResolver
+ * @since 2.3.0
+ */
+public class SinglePoolPoolResolver implements PoolResolver {
+
+	private final Pool pool;
+
+	/**
+	 * Constructs an instance of {@link SinglePoolPoolResolver} initialized with the given {@link Pool}
+	 * returned during resolution.
+	 *
+	 * @param pool {@link Pool} object resolved by this {@link PoolResolver}.
+	 * @throws IllegalArgumentException if {@link Pool} is {@literal null}.
+	 * @see org.apache.geode.cache.client.Pool
+	 */
+	public SinglePoolPoolResolver(@NonNull Pool pool) {
+
+		Assert.notNull(pool, "Pool must not be null");
+
+		this.pool = pool;
+	}
+
+	/**
+	 * Returns a reference to the configured, "resolvable" {@link Pool}.
+	 *
+	 * @return a reference to the configured, "resolvable" {@link Pool}.
+	 * @see org.apache.geode.cache.client.Pool
+	 */
+	protected @NonNull Pool getPool() {
+		return this.pool;
+	}
+
+	/**
+	 * Returns the configured {@link Pool} iff the given {@link String poolName} matches
+	 * the configured {@link Pool} {@link Pool#getName() name}.
+	 *
+	 * @param poolName {@link String name} of the {@link Pool} to resolve.
+	 * @return the configured {@link Pool} if the configured {@link Pool} {@link Pool#getName() name}
+	 * and the given {@link String poolName} match.
+	 * @see org.apache.geode.cache.client.Pool#getName()
+	 */
+	@Nullable @Override
+	public Pool resolve(@Nullable String poolName) {
+
+		Pool pool = getPool();
+
+		return pool.getName().equals(poolName) ? pool : null;
+	}
+}

spring-data-geode/src/test/java/org/springframework/data/gemfire/client/support/SinglePoolPoolResolverUnitTests.java

@@ -0,0 +1,112 @@
+/*
+ * Copyright 2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.gemfire.client.support;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.junit.MockitoJUnitRunner;
+
+import org.apache.geode.cache.client.Pool;
+
+import org.springframework.data.gemfire.client.PoolResolver;
+
+/**
+ * Unit Tests for {@link SinglePoolPoolResolver}.
+ *
+ * @author John Blum
+ * @see org.junit.Test
+ * @see org.mockito.Mock
+ * @see org.mockito.Mockito
+ * @see org.mockito.junit.MockitoJUnitRunner
+ * @see org.apache.geode.cache.client.Pool
+ * @see org.springframework.data.gemfire.client.support.SinglePoolPoolResolver
+ * @since 2.3.0
+ */
+@RunWith(MockitoJUnitRunner.class)
+public class SinglePoolPoolResolverUnitTests {
+
+	@Mock
+	private Pool mockPool;
+
+	@Test
+	public void constructSinglePoolPoolResolver() {
+
+		SinglePoolPoolResolver poolResolver = new SinglePoolPoolResolver(this.mockPool);
+
+		assertThat(poolResolver).isNotNull();
+		assertThat(poolResolver.getPool()).isEqualTo(this.mockPool);
+	}
+
+	@SuppressWarnings("all")
+	@Test(expected = IllegalArgumentException.class)
+	public void constructSinglePoolPoolResolverWithNullPoolThrowsIllegalArgumentException() {
+
+		try {
+			new SinglePoolPoolResolver(null);
+		}
+		catch (IllegalArgumentException expected) {
+
+			assertThat(expected).hasMessage("Pool must not be null");
+			assertThat(expected).hasNoCause();
+
+			throw expected;
+		}
+	}
+
+	@Test
+	public void resolvesReturnsPoolWhenNamesMatch() {
+
+		PoolResolver poolResolver = new SinglePoolPoolResolver(this.mockPool);
+
+		when(this.mockPool.getName()).thenReturn("TestPool");
+
+		assertThat(poolResolver.resolve("TestPool")).isEqualTo(this.mockPool);
+
+		verify(this.mockPool, times(1)).getName();
+	}
+
+	@Test
+	public void resolveReturnsNullWhenNamesDoNotMatch() {
+
+		PoolResolver poolResolver = new SinglePoolPoolResolver(this.mockPool);
+
+		when(this.mockPool.getName()).thenReturn("TestPool");
+
+		assertThat(poolResolver.resolve("MockPool")).isNull();
+		assertThat(poolResolver.resolve("  ")).isNull();
+		assertThat(poolResolver.resolve("")).isNull();
+
+		verify(this.mockPool, times(3)).getName();
+	}
+
+	@Test
+	public void resolveIsNullSafe() {
+
+		PoolResolver poolResolver = new SinglePoolPoolResolver(this.mockPool);
+
+		when(this.mockPool.getName()).thenReturn("TestPool");
+
+		assertThat(poolResolver.resolve((String) null)).isNull();
+
+		verify(this.mockPool, times(1)).getName();
+	}
+}