74 lines
2.3 KiB
Python
74 lines
2.3 KiB
Python
from confluent_kafka import Consumer, KafkaException
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import json
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import time
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# Kafka 配置
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conf = {
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'bootstrap.servers': 'niit-node3:9092',
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'group.id': 'recommendation-group',
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'auto.offset.reset': 'earliest'
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}
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consumer = Consumer(conf)
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consumer.subscribe(['orders'])
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# 状态存储：category -> { product -> (total_rating, count) }
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product_ratings = {}
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def update_product_rating(category, product, rating):
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if category not in product_ratings:
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product_ratings[category] = {}
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ratings = product_ratings[category]
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if product in ratings:
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total, cnt = ratings[product]
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ratings[product] = (total + rating, cnt + 1)
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else:
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ratings[product] = (rating, 1)
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def get_top_n_products(ratings_dict, n=3):
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# 计算平均评分并排序
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rated_products = [
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(prod, total / cnt) for prod, (total, cnt) in ratings_dict.items()
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]
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rated_products.sort(key=lambda x: x[1], reverse=True)
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return [p[0] for p in rated_products[:n]]
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try:
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while True:
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msg = consumer.poll(timeout=1.0)
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if msg is None:
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continue
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if msg.error():
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if msg.error().code() == KafkaException._PARTITION_EOF:
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print(f"Reached end of partition: {msg.topic()} [{msg.partition()}]")
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else:
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raise KafkaException(msg.error())
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else:
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# 解析消息内容
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try:
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# 注意：Java 生产者发送的是 tab 分隔的字符串，不是 JSON
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line = msg.value().decode('utf-8').strip()
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parts = line.split('\t')
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if len(parts) != 6:
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continue
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category, product, quantity, date, rating_str, is_valid = parts
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if is_valid != "Y":
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continue
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rating = int(rating_str)
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# 更新评分
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update_product_rating(category, product, rating)
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# 获取当前类别下的 Top 3
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top3 = get_top_n_products(product_ratings[category])
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print(f"[{category}] Top 3: {', '.join(top3)}")
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except Exception as e:
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print("Error parsing message:", str(e))
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continue
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except KeyboardInterrupt:
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print("Stopping consumer...")
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finally:
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consumer.close() |