Design And Realization Of News Search Engine Based On Java

Besides television, radio and newspaper, Internet has already become an impotent media and the main source where people can obtain news. To find out the news we are concerned with from so many news sites is the basic task of news search engine. Delivering the latest news about the important affairs to users is also what today's news service cares. To fast train, developing digital passenger information system is one of the measures to improve the soft setting of the service so that passengers can enjoy the mobile digital service. Adopting search technique, database technique and network technique, the thesis realizes the news search engine that applies to the system and provides real time news for fast train.At first the thesis introduces the search engine and explains the basic principle of the search engine and relevant techniques. Then topic search engine is presented, and the methods to improve the topic search are discussed. The thesis focuses on the news search engine, one sort of topic search engine. It analyzes the half structure web page data model and the characteristics of news web pages, expatiates the algorithms of fetching news web pages and extracting news texts in detail. Robot program fetches news from Internet and puts it into database. Client program provides sorted news and keyword search functions for users. Users can personalize their news searches, limit news refresh interval and news search source and etc. In accordance with users' setting, program refreshes news information timely.The result of test shows that this news search engine meets the demand of fast rail passenger information system and achieves the anticipated design effect. It has practical significance to digital fast train in china, and meanwhile offers reference for other related projects.