Add generic GemFire findByIndexNameAndIndexValue support

Fixes gh-353

spring-session/src/main/java/org/springframework/session/data/gemfire/AbstractGemFireOperationsSessionRepository.java

@@ -21,10 +21,13 @@ import java.io.DataOutput;
 import java.io.IOException;
 import java.text.DateFormat;
 import java.text.SimpleDateFormat;
+import java.util.AbstractMap;
+import java.util.AbstractSet;
 import java.util.Collections;
 import java.util.Date;
 import java.util.HashMap;
 import java.util.HashSet;
+import java.util.Iterator;
 import java.util.Map;
 import java.util.Set;
 import java.util.UUID;
@@ -325,6 +328,8 @@ public abstract class AbstractGemFireOperationsSessionRepository extends CacheLi
 
 		protected static final DateFormat TO_STRING_DATE_FORMAT = new SimpleDateFormat("YYYY-MM-dd-HH-mm-ss");
 
+		protected static final String SPRING_SECURITY_CONTEXT = "SPRING_SECURITY_CONTEXT";
+
 		static {
 			Instantiator.register(new Instantiator(GemFireSession.class, 800813552) {
 				@Override public DataSerializable newInstance() {
@@ -333,10 +338,6 @@ public abstract class AbstractGemFireOperationsSessionRepository extends CacheLi
 			});
 		}
 
-		private String SPRING_SECURITY_CONTEXT = "SPRING_SECURITY_CONTEXT";
-
-		private SpelExpressionParser parser = new SpelExpressionParser();
-
 		private transient boolean delta = false;
 
 		private int maxInactiveIntervalInSeconds;
@@ -346,6 +347,8 @@ public abstract class AbstractGemFireOperationsSessionRepository extends CacheLi
 
 		private transient final GemFireSessionAttributes sessionAttributes = new GemFireSessionAttributes(this);
 
+		private transient final SpelExpressionParser parser = new SpelExpressionParser();
+
 		private String id;
 
 		/* (non-Javadoc) */
@@ -426,6 +429,11 @@ public abstract class AbstractGemFireOperationsSessionRepository extends CacheLi
 			return sessionAttributes.getAttributeNames();
 		}
 
+		/* (non-Javadoc) */
+		public GemFireSessionAttributes getAttributes() {
+			return sessionAttributes;
+		}
+
 		/* (non-Javadoc) */
 		public synchronized boolean isExpired() {
 			long lastAccessedTime = getLastAccessedTime();
@@ -464,21 +472,23 @@ public abstract class AbstractGemFireOperationsSessionRepository extends CacheLi
 
 		/* (non-Javadoc) */
 		public synchronized void setPrincipalName(String principalName) {
-			setAttribute(FindByIndexNameSessionRepository.PRINCIPAL_NAME_INDEX_NAME, principalName);
+			setAttribute(PRINCIPAL_NAME_INDEX_NAME, principalName);
 		}
 
 		/* (non-Javadoc) */
 		public synchronized String getPrincipalName() {
-			String principalName = getAttribute(FindByIndexNameSessionRepository.PRINCIPAL_NAME_INDEX_NAME);
-			if(principalName != null) {
-				return principalName;
+			String principalName = getAttribute(PRINCIPAL_NAME_INDEX_NAME);
+
+			if (principalName == null) {
+				Object authentication = getAttribute(SPRING_SECURITY_CONTEXT);
+
+				if (authentication != null) {
+					Expression expression = parser.parseExpression("authentication?.name");
+					principalName = expression.getValue(authentication, String.class);
+				}
 			}
-			Object authentication = getAttribute(SPRING_SECURITY_CONTEXT);
-			if(authentication != null) {
-				Expression expression = parser.parseExpression("authentication?.name");
-				return expression.getValue(authentication, String.class);
-			}
-			return null;
+
+			return principalName;
 		}
 
 		/* (non-Javadoc) */
@@ -597,17 +607,20 @@ public abstract class AbstractGemFireOperationsSessionRepository extends CacheLi
 	}
 
 	/**
-	 * The GemFireSessionAttributes class is a container for a Session attributes that implements both
+	 * The GemFireSessionAttributes class is a container for Session attributes that implements both
 	 * the {@link DataSerializable} and {@link Delta} GemFire interfaces for efficient storage and distribution
-	 * (replication) in GemFire.
+	 * (replication) in GemFire.  Additionally, GemFireSessionAttributes extends {@link AbstractMap} providing
+	 * {@link Map}-like behavior since attributes of a Session are effectively a name to value mapping.
 	 *
+	 * @see java.util.AbstractMap
 	 * @see com.gemstone.gemfire.DataSerializable
 	 * @see com.gemstone.gemfire.DataSerializer
 	 * @see com.gemstone.gemfire.Delta
 	 * @see com.gemstone.gemfire.Instantiator
 	 */
 	@SuppressWarnings("serial")
-	public static class GemFireSessionAttributes implements DataSerializable, Delta {
+	public static class GemFireSessionAttributes extends AbstractMap<String, Object>
+			implements DataSerializable, Delta {
 
 		protected static final boolean DEFAULT_ALLOW_JAVA_SERIALIZATION = true;
 
@@ -677,6 +690,21 @@ public abstract class AbstractGemFireOperationsSessionRepository extends CacheLi
 			return DEFAULT_ALLOW_JAVA_SERIALIZATION;
 		}
 
+		/* (non-Javadoc); NOTE: entrySet implementation is not Thread-safe. */
+		@Override
+		@SuppressWarnings("all")
+		public Set<Entry<String, Object>> entrySet() {
+			return new AbstractSet<Entry<String, Object>>() {
+				@Override public Iterator<Entry<String, Object>> iterator() {
+					return Collections.unmodifiableMap(sessionAttributes).entrySet().iterator();
+				}
+
+				@Override public int size() {
+					return sessionAttributes.size();
+				}
+			};
+		}
+
 		/* (non-Javadoc) */
 		public void from(Session session) {
 			synchronized (lock) {

spring-session/src/main/java/org/springframework/session/data/gemfire/GemFireOperationsSessionRepository.java

@@ -16,7 +16,6 @@
 
 package org.springframework.session.data.gemfire;
 
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -38,6 +37,10 @@ import com.gemstone.gemfire.cache.query.SelectResults;
  */
 public class GemFireOperationsSessionRepository extends AbstractGemFireOperationsSessionRepository {
 
+	// GemFire OQL query used to lookup Sessions by arbitrary attributes.
+	protected static final String FIND_SESSIONS_BY_INDEX_NAME_VALUE_QUERY =
+		"SELECT s FROM %1$s s WHERE s.attributes['%2$s'] = $1";
+
 	// GemFire OQL query used to look up Sessions by principal name.
 	protected static final String FIND_SESSIONS_BY_PRINCIPAL_NAME_QUERY =
 		"SELECT s FROM %1$s s WHERE s.principalName = $1";
@@ -54,19 +57,18 @@ public class GemFireOperationsSessionRepository extends AbstractGemFireOperation
 	}
 
 	/**
-	 * Looks up all the available Sessions tied to the specific user identified by principal name.
+	 * Looks up all available Sessions with the particular attribute indexed by name having the given value.
 	 *
-	 * @param indexName the name of the indexed value (i.e. FindByIndexNameSessionRepository.PRINCIPAL_NAME_INDEX_NAME).
-	 * @param indexValue the value of the index to search for (i.e. username) to search for all existing Spring Sessions.
+	 * @param indexName name of the indexed Session attribute.
+	 * (e.g. {@link org.springframework.session.FindByIndexNameSessionRepository#PRINCIPAL_NAME_INDEX_NAME}).
+	 * @param indexValue value of the indexed Session attribute to search on (e.g. username).
 	 * @return a mapping of Session ID to Session instances.
 	 * @see org.springframework.session.ExpiringSession
+	 * @see java.util.Map
+	 * @see #prepareQuery(String)
 	 */
 	public Map<String, ExpiringSession> findByIndexNameAndIndexValue(String indexName, String indexValue) {
-		if(!PRINCIPAL_NAME_INDEX_NAME.equals(indexName)) {
-			return Collections.emptyMap();
-		}
-		SelectResults<ExpiringSession> results = getTemplate().find(String.format(
-			FIND_SESSIONS_BY_PRINCIPAL_NAME_QUERY, getFullyQualifiedRegionName()), indexValue);
+		SelectResults<ExpiringSession> results = getTemplate().find(prepareQuery(indexName), indexValue);
 
 		Map<String, ExpiringSession> sessions = new HashMap<String, ExpiringSession>(results.size());
 
@@ -77,6 +79,18 @@ public class GemFireOperationsSessionRepository extends AbstractGemFireOperation
 		return sessions;
 	}
 
+	/**
+	 * Prepares the appropriate GemFire OQL query based on the indexed Session attribute name.
+	 *
+	 * @param indexName a String indicating the name of the indexed Session attribute.
+	 * @return an appropriate GemFire OQL statement for querying on a particular indexed Session attribute.
+	 */
+	protected String prepareQuery(String indexName) {
+		return (PRINCIPAL_NAME_INDEX_NAME.equals(indexName)
+			? String.format(FIND_SESSIONS_BY_PRINCIPAL_NAME_QUERY, getFullyQualifiedRegionName())
+			: String.format(FIND_SESSIONS_BY_INDEX_NAME_VALUE_QUERY, getFullyQualifiedRegionName(), indexName));
+	}
+
 	/**
 	 * Constructs a new {@link ExpiringSession} instance backed by GemFire.
 	 *

spring-session/src/main/java/org/springframework/session/data/gemfire/config/annotation/web/http/EnableGemFireHttpSession.java

@@ -116,6 +116,14 @@ public @interface EnableGemFireHttpSession {
 	 */
 	ClientRegionShortcut clientRegionShortcut() default ClientRegionShortcut.PROXY;
 
+	/**
+	 * Identifies the Session attributes by name that should be indexed for query operations.
+	 * For instance, find all Sessions in GemFire having attribute A defined with value X.
+	 *
+	 * @return an array of Strings identifying the names of Session attributes to index.
+	 */
+	String[] indexableSessionAttributes() default {};
+
 	/**
 	 * Defines the maximum interval in seconds that a Session can remain inactive before it is considered expired.
 	 * Defaults to 1800 seconds, or 30 minutes.

spring-session/src/main/java/org/springframework/session/data/gemfire/config/annotation/web/http/GemFireHttpSessionConfiguration.java

@@ -37,6 +37,7 @@ import org.springframework.session.data.gemfire.AbstractGemFireOperationsSession
 import org.springframework.session.data.gemfire.GemFireOperationsSessionRepository;
 import org.springframework.session.data.gemfire.config.annotation.web.http.support.GemFireCacheTypeAwareRegionFactoryBean;
 import org.springframework.session.data.gemfire.support.GemFireUtils;
+import org.springframework.util.ObjectUtils;
 import org.springframework.util.StringUtils;
 
 import com.gemstone.gemfire.cache.ExpirationAction;
@@ -68,6 +69,8 @@ import com.gemstone.gemfire.cache.client.ClientRegionShortcut;
  * @see com.gemstone.gemfire.cache.GemFireCache
  * @see com.gemstone.gemfire.cache.Region
  * @see com.gemstone.gemfire.cache.RegionAttributes
+ * @see com.gemstone.gemfire.cache.RegionShortcut
+ * @see com.gemstone.gemfire.cache.client.ClientRegionShortcut
  * @since 1.1.0
  */
 @Configuration
@@ -85,6 +88,8 @@ public class GemFireHttpSessionConfiguration extends SpringHttpSessionConfigurat
 
 	public static final String DEFAULT_SPRING_SESSION_GEMFIRE_REGION_NAME = "ClusteredSpringSessions";
 
+	public static final String[] DEFAULT_INDEXABLE_SESSION_ATTRIBUTES = new String[0];
+
 	private int maxInactiveIntervalInSeconds = DEFAULT_MAX_INACTIVE_INTERVAL_IN_SECONDS;
 
 	private ClassLoader beanClassLoader;
@@ -95,6 +100,8 @@ public class GemFireHttpSessionConfiguration extends SpringHttpSessionConfigurat
 
 	private String springSessionGemFireRegionName = DEFAULT_SPRING_SESSION_GEMFIRE_REGION_NAME;
 
+	private String[] indexableSessionAttributes = DEFAULT_INDEXABLE_SESSION_ATTRIBUTES;
+
 	/**
 	 * Sets a reference to the {@link ClassLoader} used to load bean definition class types in a Spring context.
 	 *
@@ -133,11 +140,55 @@ public class GemFireHttpSessionConfiguration extends SpringHttpSessionConfigurat
 	 *
 	 * @return the ClientRegionShortcut used to configure the GemFire ClientCache Region.
 	 * @see com.gemstone.gemfire.cache.client.ClientRegionShortcut
+	 * @see EnableGemFireHttpSession#clientRegionShortcut()
 	 */
 	protected ClientRegionShortcut getClientRegionShortcut() {
 		return (clientRegionShortcut != null ? clientRegionShortcut : DEFAULT_CLIENT_REGION_SHORTCUT);
 	}
 
+	/**
+	 * Sets the names of all Session attributes that should be indexed by GemFire.
+	 *
+	 * @param indexableSessionAttributes an array of Strings indicating the names of all Session attributes
+	 * for which an Index will be created by GemFire.
+	 */
+	public void setIndexableSessionAttributes(String[] indexableSessionAttributes) {
+		this.indexableSessionAttributes = indexableSessionAttributes;
+	}
+
+	/**
+	 * Get the names of all Session attributes that should be indexed by GemFire.
+	 *
+	 * @return an array of Strings indicating the names of all Session attributes for which an Index
+	 * will be created by GemFire. Defaults to an empty String array if unspecified.
+	 * @see EnableGemFireHttpSession#indexableSessionAttributes()
+	 */
+	protected String[] getIndexableSessionAttributes() {
+		return (indexableSessionAttributes != null ? indexableSessionAttributes : DEFAULT_INDEXABLE_SESSION_ATTRIBUTES);
+	}
+
+	/**
+	 * Gets the names of all Session attributes that will be indexed by GemFire as single String value constituting
+	 * the Index expression of the Index definition.
+	 *
+	 * @return a String composed of all the named Session attributes on which a GemFire Index will be created
+	 * as an Index definition expression.  If the indexable Session attributes were not specified, then the
+	 * wildcard ("*") is returned.
+	 * @see com.gemstone.gemfire.cache.query.Index#getIndexedExpression()
+	 */
+	protected String getIndexableSessionAttributesAsGemFireIndexExpression() {
+		StringBuilder builder = new StringBuilder();
+
+		for (String sessionAttribute : getIndexableSessionAttributes()) {
+			builder.append(builder.length() > 0 ? ", " : "");
+			builder.append(String.format("'%1$s'", sessionAttribute));
+		}
+
+		String indexExpression = builder.toString();
+
+		return (indexExpression.isEmpty() ? "*" : indexExpression);
+	}
+
 	/**
 	 * Sets the maximum interval in seconds in which a Session can remain inactive before it is considered expired.
 	 *
@@ -153,6 +204,7 @@ public class GemFireHttpSessionConfiguration extends SpringHttpSessionConfigurat
 	 *
 	 * @return an integer value specifying the maximum interval in seconds that a Session can remain inactive
 	 * before it is considered expired.
+	 * @see EnableGemFireHttpSession#maxInactiveIntervalInSeconds()
 	 */
 	protected int getMaxInactiveIntervalInSeconds() {
 		return maxInactiveIntervalInSeconds;
@@ -174,6 +226,7 @@ public class GemFireHttpSessionConfiguration extends SpringHttpSessionConfigurat
 	 *
 	 * @return the RegionShortcut used to configure the GemFire Cache Region.
 	 * @see com.gemstone.gemfire.cache.RegionShortcut
+	 * @see EnableGemFireHttpSession#serverRegionShortcut()
 	 */
 	protected RegionShortcut getServerRegionShortcut() {
 		return (serverRegionShortcut != null ? serverRegionShortcut : DEFAULT_SERVER_REGION_SHORTCUT);
@@ -195,6 +248,7 @@ public class GemFireHttpSessionConfiguration extends SpringHttpSessionConfigurat
 	 * @return a String specifying the name of the GemFire (Client)Cache Region
 	 * used to store the Session.
 	 * @see com.gemstone.gemfire.cache.Region#getName()
+	 * @see EnableGemFireHttpSession#regionName()
 	 */
 	protected String getSpringSessionGemFireRegionName() {
 		return (StringUtils.hasText(springSessionGemFireRegionName) ? springSessionGemFireRegionName
@@ -216,6 +270,9 @@ public class GemFireHttpSessionConfiguration extends SpringHttpSessionConfigurat
 		setClientRegionShortcut(ClientRegionShortcut.class.cast(enableGemFireHttpSessionAnnotationAttributes.getEnum(
 			"clientRegionShortcut")));
 
+		setIndexableSessionAttributes(enableGemFireHttpSessionAnnotationAttributes.getStringArray(
+			"indexableSessionAttributes"));
+
 		setMaxInactiveIntervalInSeconds(enableGemFireHttpSessionAnnotationAttributes.getNumber(
 			"maxInactiveIntervalInSeconds").intValue());
 
@@ -359,7 +416,7 @@ public class GemFireHttpSessionConfiguration extends SpringHttpSessionConfigurat
 		};
 
 		index.setCache(gemfireCache);
-		index.setName("principalNameIdx");
+		index.setName("principalNameIndex");
 		index.setExpression("principalName");
 		index.setFrom(GemFireUtils.toRegionPath(getSpringSessionGemFireRegionName()));
 		index.setOverride(true);
@@ -368,4 +425,34 @@ public class GemFireHttpSessionConfiguration extends SpringHttpSessionConfigurat
 		return index;
 	}
 
+	/**
+	 * Defines a Spring GemFire Index bean on the GemFire cache {@link Region} storing and managing Sessions,
+	 * specifically on Session attributes for quick lookup and queries on Session attribute names with a given value.
+	 * This index will only be created on a server @{link Region}.
+	 *
+	 * @param gemfireCache a reference to the GemFire cache.
+	 * @return a IndexFactoryBean creating an GemFire Index on attributes of Sessions stored in the GemFire cache {@link Region}.
+	 * @see org.springframework.data.gemfire.IndexFactoryBean
+	 * @see com.gemstone.gemfire.cache.GemFireCache
+	 */
+	@Bean
+	@DependsOn(DEFAULT_SPRING_SESSION_GEMFIRE_REGION_NAME)
+	public IndexFactoryBean sessionAttributesIndex(final GemFireCache gemfireCache) {
+		IndexFactoryBean index = new IndexFactoryBean() {
+			@Override public void afterPropertiesSet() throws Exception {
+				if (GemFireUtils.isPeer(gemfireCache) && !ObjectUtils.isEmpty(getIndexableSessionAttributes())) {
+					super.afterPropertiesSet();
+				}
+			}
+		};
+
+		index.setCache(gemfireCache);
+		index.setName("sessionAttributesIndex");
+		index.setExpression(String.format("s.attributes[%1$s]", getIndexableSessionAttributesAsGemFireIndexExpression()));
+		index.setFrom(String.format("%1$s s", GemFireUtils.toRegionPath(getSpringSessionGemFireRegionName())));
+		index.setOverride(true);
+
+		return index;
+	}
+
 }