Add popFirst and popLast methods to RedisZSet.

See #2007
Original Pull Request: #2088

src/main/java/org/springframework/data/redis/support/collections/DefaultRedisZSet.java

@@ -19,6 +19,7 @@ import java.util.Collection;
 import java.util.Iterator;
 import java.util.NoSuchElementException;
 import java.util.Set;
+import java.util.concurrent.TimeUnit;
 
 import org.springframework.data.redis.connection.DataType;
 import org.springframework.data.redis.connection.RedisZSetCommands.Limit;
@@ -380,6 +381,38 @@ public class DefaultRedisZSet<E> extends AbstractRedisCollection<E> implements R
 		throw new NoSuchElementException();
 	}
 
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.redis.support.collections.RedisZSet#popFirst()
+	 */
+	@Override
+	public E popFirst() {
+
+		TypedTuple<E> tuple = boundZSetOps.popMin();
+
+		if (tuple != null) {
+			return tuple.getValue();
+		}
+
+		throw new NoSuchElementException();
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.redis.support.collections.RedisZSet#popFirst(long, java.util.concurrent.TimeUnit)
+	 */
+	@Override
+	public E popFirst(long timeout, TimeUnit unit) {
+
+		TypedTuple<E> tuple = boundZSetOps.popMin(timeout, unit);
+
+		if (tuple != null) {
+			return tuple.getValue();
+		}
+
+		throw new NoSuchElementException();
+	}
+
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.support.collections.RedisZSet#last()
@@ -397,6 +430,38 @@ public class DefaultRedisZSet<E> extends AbstractRedisCollection<E> implements R
 		throw new NoSuchElementException();
 	}
 
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.redis.support.collections.RedisZSet#popLast()
+	 */
+	@Override
+	public E popLast() {
+
+		TypedTuple<E> tuple = boundZSetOps.popMax();
+
+		if (tuple != null) {
+			return tuple.getValue();
+		}
+
+		throw new NoSuchElementException();
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.redis.support.collections.RedisZSet#popLast(long, java.util.concurrent.TimeUnit)
+	 */
+	@Override
+	public E popLast(long timeout, TimeUnit unit) {
+
+		TypedTuple<E> tuple = boundZSetOps.popMax(timeout, unit);
+
+		if (tuple != null) {
+			return tuple.getValue();
+		}
+
+		throw new NoSuchElementException();
+	}
+
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.redis.support.collections.RedisZSet#rank(java.lang.Object)

src/main/java/org/springframework/data/redis/support/collections/RedisZSet.java

@@ -21,6 +21,7 @@ import java.util.Iterator;
 import java.util.NoSuchElementException;
 import java.util.Set;
 import java.util.SortedSet;
+import java.util.concurrent.TimeUnit;
 
 import org.springframework.data.redis.connection.RedisZSetCommands.Limit;
 import org.springframework.data.redis.connection.RedisZSetCommands.Range;
@@ -217,6 +218,28 @@ public interface RedisZSet<E> extends RedisCollection<E>, Set<E> {
 	 */
 	E first();
 
+	/**
+	 * Removes the first (lowest) object at the top of this sorted set and returns that object as the value of this
+	 * function.
+	 *
+	 * @return the first (lowest) element currently in this sorted set.
+	 * @throws NoSuchElementException sorted set is empty.
+	 * @since 2.6
+	 */
+	E popFirst();
+
+	/**
+	 * Removes the first (lowest) object at the top of this sorted set and returns that object as the value of this
+	 * function. <b>Blocks connection</b> until element available or {@code timeout} reached.
+	 *
+	 * @param timeout
+	 * @param unit must not be {@literal null}.
+	 * @return the first (lowest) element currently in this sorted set.
+	 * @throws NoSuchElementException sorted set is empty.
+	 * @since 2.6
+	 */
+	E popFirst(long timeout, TimeUnit unit);
+
 	/**
 	 * Returns the last (highest) element currently in this sorted set.
 	 *
@@ -225,6 +248,28 @@ public interface RedisZSet<E> extends RedisCollection<E>, Set<E> {
 	 */
 	E last();
 
+	/**
+	 * Removes the last (highest) object at the top of this sorted set and returns that object as the value of this
+	 * function.
+	 *
+	 * @return the last (highest) element currently in this sorted set.
+	 * @throws NoSuchElementException sorted set is empty.
+	 * @since 2.6
+	 */
+	E popLast();
+
+	/**
+	 * Removes the last (highest) object at the top of this sorted set and returns that object as the value of this
+	 * function. <b>Blocks connection</b> until element available or {@code timeout} reached.
+	 *
+	 * @param timeout
+	 * @param unit must not be {@literal null}.
+	 * @return the last (highest) element currently in this sorted set.
+	 * @throws NoSuchElementException sorted set is empty.
+	 * @since 2.6
+	 */
+	E popLast(long timeout, TimeUnit unit);
+
 	/**
 	 * @since 1.4
 	 * @return