如何使用Java客户端驱动程序在Cassandra中获取行计数估计值

<dependency>
    <groupId>com.datastax.oss</groupId>
    <artifactId>java-driver-core</artifactId>
    <version>4.13.0</version>
</dependency>

import com.datastax.oss.driver.api.core.CqlSession;
import com.datastax.oss.driver.api.core.CqlSessionBuilder;
import com.datastax.oss.driver.api.core.CqlSessionBuilder;

public class CassandraClient {
    private static final String CONTACT_POINTS = "127.0.0.1"; // Cassandra节点IP地址
    private static final int PORT = 9042; // Cassandra节点端口号

    public static void main(String[] args) {
        CqlSession session = CqlSession.builder()
                .addContactPoint(new InetSocketAddress(CONTACT_POINTS, PORT))
                .build();
        
        // 在这里执行获取行计数估计值的操作
        // ...
        
        session.close();
    }
}

import com.datastax.oss.driver.api.core.CqlSession;
import com.datastax.oss.driver.api.core.CqlSessionBuilder;
import com.datastax.oss.driver.api.core.cql.ResultSet;
import com.datastax.oss.driver.api.core.cql.Row;

public class CassandraClient {
    // ...

    public static void main(String[] args) {
        // ...

        String keyspace = "your_keyspace"; // 替换为实际的Cassandra keyspace名称
        String table = "your_table"; // 替换为实际的表名称

        String query = String.format("SELECT COUNT(*) FROM %s.%s", keyspace, table);
        ResultSet resultSet = session.execute(query);
        Row row = resultSet.one();
        long rowCount = row.getLong(0);
        
        System.out.println("行计数估计值: " + rowCount);

        // ...
    }
}