Added Session Callback Interface.

Added describeRing() to Operations and Template.

src/main/java/org/springframework/data/cassandra/core/CassandraOperations.java

@@ -18,15 +18,23 @@ package org.springframework.data.cassandra.core;
 import java.util.List;
 
 import org.springframework.data.cassandra.convert.CassandraConverter;
+import org.springframework.data.cassandra.vo.RingMember;
 
 import com.datastax.driver.core.ResultSet;
-import com.datastax.driver.core.querybuilder.Update;
 
 /**
  * @author Alex Shvid
  */
 public interface CassandraOperations {
 
+	
+	/**
+	 * Describe the current Ring
+	 * 
+	 * @return The list of ring tokens that are active in the cluster
+	 */
+	List<RingMember> describeRing();
+	
 	/**
 	 * The table name used for the specified class by this template.
 	 * 

src/main/java/org/springframework/data/cassandra/core/CassandraTemplate.java

@@ -18,17 +18,22 @@ package org.springframework.data.cassandra.core;
 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
+import java.util.Set;
 
+import org.springframework.dao.DataAccessException;
 import org.springframework.dao.DuplicateKeyException;
 import org.springframework.dao.InvalidDataAccessApiUsageException;
 import org.springframework.dao.support.PersistenceExceptionTranslator;
 import org.springframework.data.cassandra.convert.CassandraConverter;
 import org.springframework.data.cassandra.mapping.CassandraPersistentEntity;
 import org.springframework.data.cassandra.mapping.CassandraPersistentProperty;
+import org.springframework.data.cassandra.vo.RingMember;
 import org.springframework.data.convert.EntityReader;
 import org.springframework.data.mapping.context.MappingContext;
 import org.springframework.util.Assert;
 
+import com.datastax.driver.core.Host;
+import com.datastax.driver.core.Metadata;
 import com.datastax.driver.core.ResultSet;
 import com.datastax.driver.core.Row;
 import com.datastax.driver.core.Session;
@@ -56,6 +61,54 @@ public class CassandraTemplate implements CassandraOperations {
 		this.mappingContext = this.cassandraConverter.getMappingContext();
 	}
 	
+	/* (non-Javadoc)
+	 * @see org.springframework.data.cassandra.core.CassandraOperations#describeRing()
+	 */
+	@Override
+	public List<RingMember> describeRing() {
+
+		/*
+		 * Initialize the return variable
+		 */
+		List<RingMember> ring = new ArrayList<RingMember>();
+		
+		/*
+		 * Get the cluster metadata for this session
+		 */
+		Metadata clusterMetadata = session.getCluster().getMetadata();
+		
+		/*
+		 * Get all hosts in the cluster
+		 */
+		Set<Host> hosts = clusterMetadata.getAllHosts();
+		
+		/*
+		 * Loop variables
+		 */
+		RingMember member = null;
+		
+		/*
+		 * Populate Ring with Host Metadata
+		 */
+		for (Host h: hosts) {
+			
+			member = new RingMember();
+			member.hostName = h.getAddress().getHostName();
+			member.address = h.getAddress().getHostAddress();
+			member.DC = h.getDatacenter();
+			member.rack = h.getRack();
+			
+			ring.add(member);
+		}
+		
+		/*
+		 * Return
+		 */
+		return ring;
+	
+	}
+
+	
 	public String getTableName(Class<?> entityClass) {
 		return determineTableName(entityClass);
 	}
@@ -226,4 +279,24 @@ public class CassandraTemplate implements CassandraOperations {
 		return resolved == null ? ex : resolved;
 	}
 
+	
+	/**
+	 * Execute a command at the Session Level
+	 * 
+	 * @param callback
+	 * @return
+	 */
+	protected <T> T execute(SessionCallback<T> callback) {
+		
+		Assert.notNull(callback);
+
+		try {
+			
+			return callback.doInSession(session);
+			
+		} catch (DataAccessException e) {
+			throw potentiallyConvertRuntimeException(e);
+		} 
+	}
+
 }

src/main/java/org/springframework/data/cassandra/core/SessionCallback.java

@@ -0,0 +1,25 @@
+/*
+ * Copyright 2010-2011 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
+ *
+ *      http://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.cassandra.core;
+
+import org.springframework.dao.DataAccessException;
+
+import com.datastax.driver.core.Session;
+
+public interface SessionCallback<T> {
+
+	T doInSession(Session s) throws DataAccessException;
+}

src/main/java/org/springframework/data/cassandra/vo/RingMember.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2010-2013 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
+ *
+ *      http://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.cassandra.vo;
+
+import java.io.Serializable;
+
+/**
+ * @author David Webb
+ *
+ */
+public class RingMember implements Serializable {
+	
+	/*
+	 * Ring attributes
+	 */
+	public String hostName;
+	public String address;
+	public String DC;
+	public String rack;
+	public String status;
+	public String state;
+
+
+}