What are the commonly used technologies for web crawlers?

Commonly used technologies for web crawlers include focused crawler technology, crawling strategy based on link evaluation, crawling strategy based on content evaluation, focused crawling technology, etc. Detailed introduction: 1. Focused crawler technology is a themed web crawler that adds link evaluation and content evaluation modules. The key point of its crawling strategy is to evaluate the page content and the importance of links; 2. Use Web pages as semi-structured documents, which have A lot of structural information can be used to evaluate link importance; 3. Crawling strategies based on content evaluation, etc.

Commonly used technologies for web crawlers include:

1. Focused crawler technology: Focused crawler technology is a themed web crawler that adds link evaluation And the content evaluation module, the key point of its crawling strategy is to evaluate the importance of page content and links.
2. Crawling strategy based on link evaluation: Web pages are used as semi-structured documents, which contain a lot of structural information that can be used to evaluate the importance of links.
3. Crawling strategy based on content evaluation: applying a calculation method similar to text, the Fish-Search algorithm is proposed, and the user input query words are regarded as topics. With further improvement of the algorithm, through the Shark-Search algorithm You can use the spatial vector model to calculate the page and topic relevance.
4. Focus on crawler technology: topic-oriented crawlers and demand-oriented crawlers will crawl information for a specific content and ensure that the information is as relevant as possible to the demand.

Web crawler technology is constantly being upgraded. It is recommended to consult professional technicians to learn about the latest developments.

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