package javac.db;import com.datastax.driver.core.*;import java.util.Iterator;public class Cassandra {    private static final String IP             = "127.0.0.1";    private static final String KEY_SPACE_NAME = "mykeyspace";    private static Session session             = null;    public static Session getKeyspaceSession(){        if(null == session){            QueryOptions options = new QueryOptions();            options.setConsistencyLevel(ConsistencyLevel.QUORUM);            Cluster cluster = Cluster.builder()                    .addContactPoint(IP)                    .withCredentials("cassandra", "cassandra")                    .withQueryOptions(options)                    .build();            session = cluster.connect(KEY_SPACE_NAME);        }        return session;    }    public static void main(String[] args){        Session mykeyspaceSession = getKeyspaceSession();        // 这里执行SQL（增删改查）        ResultSet result = mykeyspaceSession.execute("select * from users;");        Iterator
    
      iterator = result.iterator();        while(iterator.hasNext())        {            Row row = iterator.next();            String fname = row.getString("fname");            System.out.println(fname);        }    }}
    

datastax maven key:

"com.datastax.cassandra" % "cassandra-driver-core" % "3.0.0-alpha3",