Web crawler based application

Abstract

This article provides some basic key points about simple and complex web crawlers, xml parsers and databases. Also there are some general overview of the architecture, implementation, optimization and usage of the web crawlers. The purpose of application is to get unorganized open data from different web sites on daily basis, to filter and organize it, and to store it in a centralized database on a server for future usage. The data processed by application is currency rates from all commercial banks of Moldova. The domain of usage very large, from single price calculation to long term review of the trends of currencies.