Pelops Java客户端插入Cassandra数据库

我最近开始使用卡桑德拉数据库。我能够在本地计算机中设置单节点群集

现在我正在考虑开始使用

Pelops客户端

向Cassandra数据库写入一些示例数据

下面是我迄今为止创建的键空间和列族-

create keyspace my_keyspace with placement_strategy = 'org.apache.cassandra.locator.SimpleStrategy' and strategy_options = {replication_factor:1};
use my_keyspace;
create column family users with column_type = 'Standard' and comparator = 'UTF8Type';

下面是我到目前为止的代码。我取得了一些进步，就像以前一样，我遇到了一些异常，我能够修复它。现在我得到了另一个例外

public class MyPelops {
    private static final Logger log = Logger.getLogger(MyPelops.class);

    public static void main(String[] args) throws Exception {

        // A comma separated List of Nodes
        String NODES = "localhost";
        // Thrift Connection Pool
        String THRIFT_CONNECTION_POOL = "Test Cluster";
        // Keyspace
        String KEYSPACE = "my_keyspace";
        // Column Family
        String COLUMN_FAMILY = "users";
        Cluster cluster = new Cluster(NODES, 9160);
        Pelops.addPool(THRIFT_CONNECTION_POOL, cluster, KEYSPACE);
        Mutator mutator = Pelops.createMutator(THRIFT_CONNECTION_POOL);
        log.info("- Write Column -");
        mutator.writeColumn(
                COLUMN_FAMILY,
                "Row1",
                new Column().setName(" Name ".getBytes()).setValue(
                        " Test One ".getBytes()));
        mutator.writeColumn(
                COLUMN_FAMILY,
                "Row1",
                new Column().setName(" Work ".getBytes()).setValue(
                        " Engineer ".getBytes()));
        log.info("- Execute -");
        mutator.execute(ConsistencyLevel.ONE);
        Selector selector = Pelops.createSelector(THRIFT_CONNECTION_POOL);
        int columnCount = selector.getColumnCount(COLUMN_FAMILY, "Row1",
                ConsistencyLevel.ONE);
        log.info("- Column Count = " + columnCount);
        List<Column> columnList = selector
                .getColumnsFromRow(COLUMN_FAMILY, "Row1",
                        Selector.newColumnsPredicateAll(true, 10),
                        ConsistencyLevel.ONE);
        log.info("- Size of Column List = " + columnList.size());
        for (Column column : columnList) {
            log.info("- Column: (" + new String(column.getName()) + ","
                    + new String(column.getValue()) + ")");
        }
        log.info("- All Done. Exit -");
        System.exit(0);
    }
}

当它试图执行这一行时，这个异常就会出现-

mutator.execute

line

正如我前面提到的，我对Cassandra数据库和Pelops客户端也是新手。这是我第一次使用它。有人能帮我解决这个问题吗？我正在本地运行Cassandra 1.2.3

任何一步一步的指导，比如如何在Cassandra数据库中插入数据，都将有助于我理解Cassandra的工作原理

---

提前感谢。

每个cassandra列都是一个键值时间戳三元组。 您没有在列中设置时间戳

Column c = new Column();
c.setTimestamp(System.currentTimeMillis());

您可以使用客户机方式创建列，使工作更轻松

   mutator.writeColumn(
            COLUMN_FAMILY,
            "Row1",
            mutator.newColumn(" Name ", " Test One "));

通过这种方式，您可以避免设置时间戳（客户机将为您执行）和对字符串使用getBytes（）

你好，卡洛

   mutator.writeColumn(
            COLUMN_FAMILY,
            "Row1",
            mutator.newColumn(" Name ", " Test One "));