Add Cassandra support

Add auto-configuration support and health checks for Cassandra and
Spring Data Cassandra.

Fixes spring-projectsgh-2064
Closes spring-projectsgh-2214

spring-boot-actuator/pom.xml

@@ -147,6 +147,11 @@
 			<artifactId>spring-webmvc</artifactId>
 			<optional>true</optional>
 		</dependency>
+		<dependency>
+			<groupId>org.springframework.data</groupId>
+			<artifactId>spring-data-cassandra</artifactId>
+			<optional>true</optional>
+		</dependency>
 		<dependency>
 			<groupId>org.springframework.data</groupId>
 			<artifactId>spring-data-mongodb</artifactId>

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/health/CassandraHealthIndicator.java

@@ -0,0 +1,65 @@
+/*
+ * Copyright 2012-2015 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.boot.actuate.health;
+
+import org.springframework.data.cassandra.core.CassandraAdminOperations;
+import org.springframework.util.Assert;
+
+import com.datastax.driver.core.ResultSet;
+import com.datastax.driver.core.querybuilder.QueryBuilder;
+import com.datastax.driver.core.querybuilder.Select;
+
+/**
+ * Simple implementation of a {@link HealthIndicator} returning status information for
+ * Cassandra data stores.
+ *
+ * @author Julien Dubois
+ * @since 1.3.0
+ */
+public class CassandraHealthIndicator extends AbstractHealthIndicator {
+
+	private CassandraAdminOperations cassandraAdminOperations;
+
+	/**
+	 * Create a new {@link CassandraHealthIndicator} instance.
+	 * @param cassandraAdminOperations the Cassandra admin operations
+	 */
+	public CassandraHealthIndicator(CassandraAdminOperations cassandraAdminOperations) {
+		Assert.notNull(cassandraAdminOperations,
+				"CassandraAdminOperations must not be null");
+		this.cassandraAdminOperations = cassandraAdminOperations;
+	}
+
+	@Override
+	protected void doHealthCheck(Health.Builder builder) throws Exception {
+		try {
+			Select select = QueryBuilder.select("release_version")
+					.from("system", "local");
+			ResultSet results = this.cassandraAdminOperations.query(select);
+			if (results.isExhausted()) {
+				builder.up();
+				return;
+			}
+			String version = results.one().getString(0);
+			builder.up().withDetail("version", version);
+		}
+		catch (Exception ex) {
+			builder.down(ex);
+		}
+	}
+
+}

spring-boot-autoconfigure/pom.xml

@@ -342,6 +342,11 @@
 				</exclusion>
 			</exclusions>
 		</dependency>
+		<dependency>
+			<groupId>org.springframework.data</groupId>
+			<artifactId>spring-data-cassandra</artifactId>
+			<optional>true</optional>
+		</dependency>
 		<dependency>
 			<groupId>org.springframework.data</groupId>
 			<artifactId>spring-data-mongodb</artifactId>

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/cassandra/CassandraAutoConfiguration.java

@@ -0,0 +1,107 @@
+/*
+ * Copyright 2012-2015 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.boot.autoconfigure.cassandra;
+
+import org.springframework.beans.BeanUtils;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
+import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.util.StringUtils;
+
+import com.datastax.driver.core.Cluster;
+import com.datastax.driver.core.QueryOptions;
+import com.datastax.driver.core.SocketOptions;
+import com.datastax.driver.core.policies.LoadBalancingPolicy;
+import com.datastax.driver.core.policies.ReconnectionPolicy;
+import com.datastax.driver.core.policies.RetryPolicy;
+
+/**
+ * {@link EnableAutoConfiguration Auto-configuration} for Cassandra.
+ *
+ * @author Julien Dubois
+ * @author Phillip Webb
+ * @since 1.3.0
+ */
+@Configuration
+@ConditionalOnClass({ Cluster.class })
+@EnableConfigurationProperties(CassandraProperties.class)
+public class CassandraAutoConfiguration {
+
+	@Autowired
+	private CassandraProperties properties;
+
+	@Bean
+	@ConditionalOnMissingBean
+	public Cluster cluster() {
+		CassandraProperties properties = this.properties;
+		Cluster.Builder builder = Cluster.builder()
+				.withClusterName(properties.getClusterName())
+				.withPort(properties.getPort());
+		if (properties.getCompression() != null) {
+			builder.withCompression(properties.getCompression());
+		}
+		if (properties.getLoadBalancingPolicy() != null) {
+			LoadBalancingPolicy policy = instantiate(properties.getLoadBalancingPolicy());
+			builder.withLoadBalancingPolicy(policy);
+		}
+		builder.withQueryOptions(getQueryOptions());
+		if (properties.getReconnectionPolicy() != null) {
+			ReconnectionPolicy policy = instantiate(properties.getReconnectionPolicy());
+			builder.withReconnectionPolicy(policy);
+		}
+		if (properties.getRetryPolicy() != null) {
+			RetryPolicy policy = instantiate(properties.getRetryPolicy());
+			builder.withRetryPolicy(policy);
+		}
+		builder.withSocketOptions(getSocketOptions());
+		if (properties.isSsl()) {
+			builder.withSSL();
+		}
+		String points = properties.getContactPoints();
+		builder.addContactPoints(StringUtils.commaDelimitedListToStringArray(points));
+		return builder.build();
+	}
+
+	public static <T> T instantiate(Class<T> type) {
+		return BeanUtils.instantiate(type);
+	}
+
+	private QueryOptions getQueryOptions() {
+		QueryOptions options = new QueryOptions();
+		CassandraProperties properties = this.properties;
+		if (properties.getConsistencyLevel() != null) {
+			options.setConsistencyLevel(properties.getConsistencyLevel());
+		}
+		if (properties.getSerialConsistencyLevel() != null) {
+			options.setSerialConsistencyLevel(properties.getSerialConsistencyLevel());
+		}
+		options.setFetchSize(properties.getFetchSize());
+		return options;
+	}
+
+	private SocketOptions getSocketOptions() {
+		SocketOptions options = new SocketOptions();
+		options.setConnectTimeoutMillis(this.properties.getConnectTimeoutMillis());
+		options.setReadTimeoutMillis(this.properties.getReadTimeoutMillis());
+		return options;
+	}
+
+}