DATAKV-102 - Add possibility to iterate over available keys.

pom.xml

@@ -5,7 +5,7 @@
 
 	<groupId>org.springframework.data</groupId>
 	<artifactId>spring-data-keyvalue</artifactId>
-	<version>0.1.0.BUILD-SNAPSHOT</version>
+	<version>0.1.0.DATAKV-102-SNAPSHOT</version>
 
 	<name>Spring Data KeyValue</name>
 

src/main/java/org/springframework/data/keyvalue/core/KeyValueAdapter.java

@@ -74,13 +74,21 @@ public interface KeyValueAdapter extends DisposableBean {
 	Iterable<?> getAllOf(Serializable keyspace);
 
 	/**
-	 * Returns a {@link KeyValueIterator} that iterates over all entries. 
+	 * Returns a {@link KeyValueIterator} that iterates over all entries.
 	 * 
-	 * @param keyspace
+	 * @param keyspace must not be {@literal null}.
 	 * @return
 	 */
 	KeyValueIterator<? extends Serializable, ?> entries(Serializable keyspace);
 
+	/**
+	 * Returns all keys available in {@literal keyspace}.
+	 * 
+	 * @param keyspace must not be {@literal null}.
+	 * @return empty {@link Iterable} if no keys available or keyspace unknown.
+	 */
+	Iterable<? extends Serializable> keys(Serializable keyspace);
+
 	/**
 	 * Remove all objects of given type.
 	 * 

src/main/java/org/springframework/data/map/MapKeyValueAdapter.java

@@ -104,7 +104,6 @@ public boolean contains(Serializable id, Serializable keyspace) {
 		return get(id, keyspace) != null;
 	}
 
-
 	/* (non-Javadoc)
 	 * @see org.springframework.data.keyvalue.core.KeyValueAdapter#count(java.io.Serializable)
 	 */
@@ -153,6 +152,15 @@ public Collection<?> getAllOf(Serializable keyspace) {
 		return new ForwardingKeyValueIterator<Serializable, Object>(getKeySpaceMap(keyspace).entrySet().iterator());
 	}
 
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.keyvalue.core.KeyValueAdapter#keys(java.io.Serializable)
+	 */
+	@Override
+	public Iterable<Serializable> keys(Serializable keyspace) {
+		return getKeySpaceMap(keyspace).keySet();
+	}
+
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.keyvalue.core.KeyValueAdapter#deleteAllOf(java.io.Serializable)

src/test/java/org/springframework/data/map/MapKeyValueAdapterUnitTests.java

@@ -15,6 +15,7 @@
  */
 package org.springframework.data.map;
 
+import static org.hamcrest.collection.IsEmptyIterable.*;
 import static org.hamcrest.collection.IsIterableContainingInAnyOrder.*;
 import static org.hamcrest.core.Is.*;
 import static org.hamcrest.core.IsEqual.*;
@@ -24,6 +25,8 @@
 
 import java.io.Serializable;
 
+import org.hamcrest.collection.IsIterableContainingInAnyOrder;
+import org.hamcrest.collection.IsIterableWithSize;
 import org.junit.Before;
 import org.junit.Test;
 import org.springframework.data.keyvalue.core.KeyValueIterator;
@@ -193,7 +196,7 @@ public void deleteShouldReturnDeletedObject() {
 	 * @see DATAKV-99
 	 */
 	@Test
-	public void scanShouldIterateOverAvailableEntries() {
+	public void entriesShouldIterateOverAvailableEntries() {
 
 		adapter.put("1", object1, COLLECTION_1);
 		adapter.put("2", object2, COLLECTION_1);
@@ -209,15 +212,15 @@ public void scanShouldIterateOverAvailableEntries() {
 	 * @see DATAKV-99
 	 */
 	@Test
-	public void scanShouldReturnEmptyIteratorWhenNoElementsAvailable() {
+	public void entriesShouldReturnEmptyIteratorWhenNoElementsAvailable() {
 		assertThat(adapter.entries(COLLECTION_1).hasNext(), is(false));
 	}
 
 	/**
 	 * @see DATAKV-99
 	 */
 	@Test
-	public void scanDoesNotMixResultsFromMultipleKeyspaces() {
+	public void entriesShouldNotMixResultsFromMultipleKeyspaces() {
 
 		adapter.put("1", object1, COLLECTION_1);
 		adapter.put("2", object2, COLLECTION_2);
@@ -228,6 +231,40 @@ public void scanDoesNotMixResultsFromMultipleKeyspaces() {
 		assertThat(iterator.hasNext(), is(false));
 	}
 
+	/**
+	 * @see DATAKV-102
+	 */
+	@Test
+	public void keysShouldReturnAvailableKeys() {
+
+		adapter.put("1", object1, COLLECTION_1);
+		adapter.put("2", object2, COLLECTION_1);
+
+		Iterable<Serializable> iterable = adapter.keys(COLLECTION_1);
+
+		assertThat(iterable, IsIterableContainingInAnyOrder.<Serializable> containsInAnyOrder("1", "2"));
+	}
+
+	/**
+	 * @see DATAKV-102
+	 */
+	@Test
+	public void keyShouldReturnEmptyIterableWhenNoElementsAvailable() {
+		assertThat(adapter.keys(COLLECTION_1), emptyIterable());
+	}
+
+	/**
+	 * @see DATAKV-102
+	 */
+	@Test
+	public void keysShouldNotMixResultsFromMultipleKeyspaces() {
+
+		adapter.put("1", object1, COLLECTION_1);
+		adapter.put("2", object2, COLLECTION_2);
+
+		assertThat(adapter.keys(COLLECTION_1), IsIterableWithSize.<Serializable> iterableWithSize(1));
+	}
+
 	static class SimpleObject {
 
 		protected String stringValue;