Add requireState(..) assertion method to RedisAssertions.

Use RedisAssertions.requireState(..) in RedisAccessor.getRequiredConnectionFactory().

Closes #2611

src/main/java/org/springframework/data/redis/core/RedisAccessor.java

@@ -19,9 +19,8 @@ import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.springframework.beans.factory.InitializingBean;
 import org.springframework.data.redis.connection.RedisConnectionFactory;
-import org.springframework.lang.NonNull;
+import org.springframework.data.redis.util.RedisAssertions;
 import org.springframework.lang.Nullable;
-import org.springframework.util.Assert;
 
 /**
  * Base class for {@link RedisTemplate} defining common properties. Not intended to be used directly.
@@ -62,14 +61,8 @@ public class RedisAccessor implements InitializingBean {
 	 * @see #getConnectionFactory()
 	 * @since 2.0
 	 */
-	@NonNull
 	public RedisConnectionFactory getRequiredConnectionFactory() {
-
-		RedisConnectionFactory connectionFactory = getConnectionFactory();
-
-		Assert.state(connectionFactory != null, "RedisConnectionFactory is required");
-
-		return connectionFactory;
+		return RedisAssertions.requireState(getConnectionFactory(), "RedisConnectionFactory is required");
 	}
 
 	/**

src/main/java/org/springframework/data/redis/util/RedisAssertions.java

@@ -56,4 +56,33 @@ public abstract class RedisAssertions {
 		Assert.notNull(target, message);
 		return target;
 	}
+
+	/**
+	 * Asserts the given {@link Object} is not {@literal null}.
+	 *
+	 * @param <T> {@link Class type} of {@link Object} being asserted.
+	 * @param target {@link Object} to evaluate.
+	 * @param message {@link String} containing the message for the thrown exception.
+	 * @param arguments array of {@link Object} arguments used to format the {@link String message}.
+	 * @return the given {@link Object}.
+	 * @throws IllegalArgumentException if the {@link Object target} is {@literal null}.
+	 * @see #requireObject(Object, Supplier)
+	 */
+	public static <T> T requireState(@Nullable T target, String message, Object... arguments) {
+		return requireState(target, () -> String.format(message, arguments));
+	}
+
+	/**
+	 * Asserts the given {@link Object} is not {@literal null}.
+	 *
+	 * @param <T> {@link Class type} of {@link Object} being asserted.
+	 * @param target {@link Object} to evaluate.
+	 * @param message {@link Supplier} supplying the message for the thrown exception.
+	 * @return the given {@link Object}.
+	 * @throws IllegalArgumentException if the {@link Object target} is {@literal null}.
+	 */
+	public static <T> T requireState(@Nullable T target, Supplier<String> message) {
+		Assert.state(target != null, message);
+		return target;
+	}
 }