lucene-query query->wildcardquery using wildcard characters search

Lucene also provides a wildcard query, which is wildcardquery.

 PackageCh11;ImportOrg.apache.lucene.analysis.standard.StandardAnalyzer;Importorg.apache.lucene.document.Document;ImportOrg.apache.lucene.document.Field;ImportOrg.apache.lucene.index.IndexWriter;Importorg.apache.lucene.index.Term;Importorg.apache.lucene.search.Hits;ImportOrg.apache.lucene.search.IndexSearcher;ImportOrg.apache.lucene.search.WildcardQuery; Public classWildcardquerytest { Public Static voidMain (string[] args)throwsException {//generate Document object, same asDocument Doc1=NewDocument (); //Add the contents of the "Content" field,Doc1.add (Field.text ("Content", "whatever")); //Add the contents of the "title" field,Doc1.add (Field.keyword ("title", "Doc1")); Document doc2=NewDocument (); Doc2.add (Field.text ("Content", "whoever")); Doc2.add (Field.keyword ("title", "Doc2")); Document DOC3=NewDocument (); Doc3.add (Field.text ("Content", "however")); Doc3.add (Field.keyword ("title", "DOC3")); Document doc4=NewDocument (); Doc4.add (Field.text ("Content", "Everest")); Doc4.add (Field.keyword ("title", "Doc4")); //Generate index writerIndexWriter writer=NewIndexWriter ("C://index",                 NewStandardAnalyzer (),true); //to add a Document object to the indexwriter.adddocument (Doc1);         Writer.adddocument (DOC2);         Writer.adddocument (DOC3);         Writer.adddocument (DOC4); //Close the index writerWriter.close (); //Generate index writerIndexsearcher Searcher=NewIndexsearcher ("C://index"); //Construct EntryTerm word1=NewTerm ("content", "*ever"); Term Word2=NewTerm ("content", "Wh?ever"); Term Word3=NewTerm ("content", "H??") Ever "); Term Word4=NewTerm ("content", "ever*"); //generates a Wildcardquery object, initialized to nullwildcardquery Query=NULL; //to save the results of a searchHits Hits=NULL; Query=Newwildcardquery (WORD1); //starts the first retrieval and returns the results of the searchhits=searcher.search (query); //output information about the results of the searchPrintresult (hits,"*ever"); Query=Newwildcardquery (WORD2); //start a second search and return the results of the searchhits=searcher.search (query); //output information about the results of the searchPrintresult (hits,"Wh?ever"); Query=Newwildcardquery (WORD3); //starts a third search and returns the results of the searchhits=searcher.search (query); //output information about the results of the searchPrintresult (hits,"H??" Ever "); Query=Newwildcardquery (WORD4); //starts the fourth retrieval and returns the results of the searchhits=searcher.search (query); //output information about the results of the searchPrintresult (hits,"Ever*"); }         Public Static voidPrintresult (Hits Hits, String key)throwsException {System.out.println ("Find/" "+ Key +"/":"); if(hits! =NULL) {             if(hits.length () = = 0) {System.out.println ("No results found");             System.out.println (); } Else{System.out.print (Find);  for(inti = 0; I < hits.length (); i++) {                     //Get Document ObjectDocument D=Hits.doc (i); //get the contents of the "title" FieldString dname= D.get ("title"); System.out.print (Dname+ "   ");                 } System.out.println ();             System.out.println (); }         }     }}

As you can see from the above code, the wildcard character "?" Represents 1 characters, while "*" represents 0 characters or more. However, wildcard retrieval and fuzzyquery above are subject to some impact on the performance of the search because of the need for string matching of field keywords.

lucene-query query->wildcardquery using wildcard characters search