[Datastax] Cassandra Java Driver

I have been working with cassandra for a while.
Today I'm going to blog about "How to connect to Cassandra from Java using datastax driver."
You can download driver here and compile it.
In this post I used these jar files: cassandra-driver-core-2.1.8-SNAPSHOT.jar which was compiled from above step.
Next one is guava-18.0.jar , metrics-core-3.0.0.jar, netty-all-4.0.12.Final.jar and for logging purpose slf4j-*.jar are included.
In order to connect to cassandra cluster we will need two parameters

• contact point : list of ip address of your cluster's contact point.
• key space name: name of key space in cassandra cluster you want to connect.

       

    Cluster cluster;
    Session session;
    String[] contactList= {"10.10.10.10","10.10.10.20"};
    String keyspaceName = "test";
    cluster = Cluster.builder().addContactPoints(contactPoints).build();
    session = cluster.connect(keyspaceName);
       

After this step we will use session object to issue our queries.
For example I want to add a column into existing table:

       
     String columnFamily = "test_table";
     String colName = "new_column";
     String dataType = "text";
     String query = String.format("ALTER TABLE %s.%s ADD %s %s", keyspaceName,columnFamily,colName,dataType);
  
     try {
         session.execute(query);
     } 
     catch (Exception e) {
         slf4jLogger.error(e.toString());
  }

Insert records into existing table in this case is users table:

     session.execute(
         "INSERT INTO users (firstname, lastname, age, city, email ) VALUES ('Tin', 'Ho', 27, 'Sai Gon', 'imthientin@gmail.com')");

To acquire data from existing table:

       
     ResultSet results = session.execute("SELECT * FROM users WHERE firstname='Tin'");
     for (Row row : results) {
         System.out.format("%s %d\n", row.getString("email"), row.getInt("age"));
  }         

Some other thing we can do:

• Drop column : non primary key column
• Drop table/column family
• Drop keyspace
• Change column name: only primary key column
• etc ...

My github for source code:
https://github.com/thientin/cassandra-utils

Hope this useful.