Design And Implementation Of Xquery Is The Java Api

XQuery Java API is a Java API which can execute query and get results from query. Users can first prepare XQuery search, then kidnap XQuery search strings, and then execute it, last, it can get results of XML files by XQueryResultSet class like JDBC API. Its core is XQuery's Compiler which has some deficiencies. It can only query XML files which have schema. But in real life not all the XML files have schema, so we extend its function so that it can query no Schema XML files; furthermore, we add network function that can query URL files on the web; last, because it is impossible to construct data models of all the XML files, we adopt dymanic construction.XQuery Java API can also shied heterogenous data sources and supply users with a unified interface which can query a number of data sources. Users can achieve query aims by writing XQuery search strings. XQuery itself does not implement such function. So we extent its function by adding sqlquery expressions which contain SQL. It gets results from queries by JDBC API and convert it into XML format. Then it uses XQuery complier to query in succession in order to integrate related databases.Furthmore, we supply users with XQuery view t o query XML files safely and reliably from different views. It defines its contents with query like views of the related databases.At the end of this paper, we will give some examples of querying XML files and related databases. And according to some existing problems further works and developments will also be given.