要使用Confluent Hub而无需安装Confluent Platform，您可以使用Kafka Connect来连接到Confluent Hub并使用其插件。以下是一个使用Python的示例代码：

from confluent_kafka.admin import AdminClient
from confluent_kafka import KafkaException
import requests
import json

# Confluent Hub插件的名称
plugin_name = "confluentinc/kafka-connect-datagen:latest"

# 创建AdminClient以连接到Kafka集群
admin_client = AdminClient({"bootstrap.servers": "localhost:9092"})

# 检查是否已安装插件
def is_plugin_installed(plugin_name):
    try:
        plugins = admin_client.list_plugins().plugins
        for plugin in plugins:
            if plugin.name == plugin_name:
                return True
        return False
    except KafkaException as e:
        print(f"Failed to list plugins: {e}")
        return False

# 安装插件
def install_plugin(plugin_name):
    try:
        response = requests.post(f"http://localhost:8083/connectors/{plugin_name}/config/validate")
        if response.status_code == 200:
            config = response.json()
            if "error_count" in config and config["error_count"] > 0:
                print(f"Validation errors for plugin {plugin_name}: {json.dumps(config['config'], indent=2)}")
                return False
        else:
            print(f"Failed to validate plugin {plugin_name}: {response.text}")
            return False

        response = requests.post(f"http://localhost:8083/connectors", json={"name": plugin_name, "config": {}})
        if response.status_code == 201:
            print(f"Successfully installed plugin {plugin_name}")
            return True
        else:
            print(f"Failed to install plugin {plugin_name}: {response.text}")
            return False
    except requests.exceptions.RequestException as e:
        print(f"Failed to install plugin {plugin_name}: {e}")
        return False

# 检查插件是否已安装
if is_plugin_installed(plugin_name):
    print(f"Plugin {plugin_name} is already installed")
else:
    print(f"Installing plugin {plugin_name}...")
    install_plugin(plugin_name)

上述代码使用confluent_kafka.admin模块中的AdminClient类来连接到Kafka集群并检查插件是否已安装。然后，它使用Python的requests库发送HTTP请求来安装插件。请确保替换localhost:9092和localhost:8083为您的Kafka集群和Kafka Connect REST代理的正确地址。

请注意，这只是一个示例代码，您可能需要根据您的环境和需求进行适当的修改。