CassandraInjectedResource.java

/*
 * Copyright 2017 Composable Systems Limited
 *
 *    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 systems.composable.dropwizard.cassandra;

import com.datastax.driver.core.Cluster;
import com.datastax.driver.core.ResultSet;
import com.datastax.driver.core.Session;

import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.MediaType;
import java.util.List;
import java.util.stream.Collectors;

@Path("/")
@Produces(MediaType.APPLICATION_JSON)
public class CassandraInjectedResource {

	@Context Cluster cluster;
	@Context Session session;

	private List<String> query(Session session) {
		final ResultSet resultSet = session.execute("SELECT * FROM system_schema.columns");
		return resultSet.all().stream()
				.map(r -> r.getString(0))
				.collect(Collectors.toList());
	}

	@GET
	@Path("/querySessionField")
	public List<String> querySessionField() {
		return query(session);
	}

	@GET
	@Path("/querySessionParameter")
	public List<String> querySessionParameter(@Context Session session) {
		return query(session);
	}

	@GET
	@Path("/queryClusterField")
	public List<String> queryClusterField() {
		try (Session session = cluster.connect()) {
			return query(session);
		}
	}
}