我有这个密码：

import os
from pyspark import SparkContext,SparkFiles,SQLContext,SparkFiles
from pyspark.sql import SQLContext, SparkSession
from pyspark.sql.functions import col

secure_bundle_file=os.getcwd()+'\\secure-connect-dbtest.zip'
sparkSession =SparkSession.builder.appName('SparkCassandraApp')\
  .config('spark.cassandra.connection.config.cloud.path',secure_bundle_file)\
  .config('spark.cassandra.auth.username', 'test')\
  .config('spark.cassandra.auth.password','testquart')\
  .config('spark.dse.continuousPagingEnabled',False)\
  .master('local[*]').getOrCreate()

data = sparkSession.read.format("org.apache.spark.sql.cassandra")\
  .options(table="tbthesis", keyspace="test").load()
data.count()

我尝试做的是连接到我的数据库并检索我的数据。代码很好地连接到数据库，但一旦到达读取行，它就会说：

Exception has occurred: Py4JJavaError
An error occurred while calling o48.load.
: java.lang.ClassNotFoundException: Failed to find data source: org.apache.spark.sql.cassandra. 
Please find packages at http://spark.apache.org/third-party-projects.html
at org.apache.spark.sql.execution.datasources.DataSource$.lookupDataSource(DataSource.scala:674)
at org.apache.spark.sql.execution.datasources.DataSource$.lookupDataSourceV2(DataSource.scala:728)
at org.apache.spark.sql.DataFrameReader.load(DataFrameReader.scala:230)
at org.apache.spark.sql.DataFrameReader.load(DataFrameReader.scala:203)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at py4j.reflection.MethodInvoker.invoke(MethodInvoker.java:244)
at py4j.reflection.ReflectionEngine.invoke(ReflectionEngine.java:357)
at py4j.Gateway.invoke(Gateway.java:282)
at py4j.commands.AbstractCommand.invokeMethod(AbstractCommand.java:132)
at py4j.commands.CallCommand.execute(CallCommand.java:79)

有人能帮我吗？
另外，我还想添加一些有关此代码的详细信息：
我想做的是测试spark从我的数据库中读取200万条记录需要多长时间，普通的python cassandra驱动程序在大约1小时内读取了200万条记录（使用simplestatement），所以在这里我想知道使用spark读取这200万条记录需要多长时间。
谢谢