lucene-query query->prefixquery using prefix search

Prefixquery is the use of prefixes to find. Typically, a term is defined first . The entry contains the name of the field to look up and the prefix of the keyword, and then constructs a Prefixquery object from that entry , which can be searched by prefix.

 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.PrefixQuery;ImportOrg.apache.lucene.search.RangeQuery; Public classPrefixquerytest { Public Static voidMain (string[] args)throwsException {//generate Document object, same asDocument Doc1=NewDocument (); //Add the contents of the "Name" field,Doc1.add (Field.text ("Name", "David")); //Add the contents of the "title" field,Doc1.add (Field.keyword ("title", "Doc1")); Document doc2=NewDocument (); Doc2.add (Field.text ("Name", "Darwen")); Doc2.add (Field.keyword ("title", "Doc2")); Document DOC3=NewDocument (); Doc3.add (Field.text ("Name", "Smith")); Doc3.add (Field.keyword ("title", "DOC3")); Document doc4=NewDocument (); Doc4.add (Field.text ("Name", "Smart")); Doc4.add (Field.keyword ("title", "Doc4")); //Generate index writerIndexWriter writer=NewIndexWriter ("C://index",                 NewStandardAnalyzer (),true); //set to mixed index modeWriter.setusecompoundfile (true); //add a document to the index in turnwriter.adddocument (Doc1);         Writer.adddocument (DOC2);         Writer.adddocument (DOC3);         Writer.adddocument (DOC4); //Close the index writerWriter.close (); //Build Index Finder objectIndexsearcher Searcher=NewIndexsearcher ("C://index"); //Construct EntryTerm pre1=NewTerm ("name", "Da"); Term Pre2=NewTerm ("name", "Da"); Term pre3=NewTerm ("name", "SM"); //to save the results of a searchHits Hits=NULL; //generates an object of type prefixquery, initialized to nullprefixquery Query=NULL; Query=Newprefixquery (Pre1); //starts the first retrieval and returns the results of the searchhits=searcher.search (query); //output The corresponding search resultsPrintresult (hits,"Document prefixed with ' Da '"); Query=Newprefixquery (Pre2); //start a second search and return the results of the searchhits=searcher.search (query); //output The corresponding search resultsPrintresult (hits,"Document prefixed with ' da '"); Query=Newprefixquery (pre3); //start a second search and return the results of the searchhits=searcher.search (query); //output The corresponding search resultsPrintresult (hits,"Document prefixed with ' SM '"); }       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 DocumentationDocument 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 (); }         }     }}

In the code, 4 different Document constructs are constructed first . Each document has a field named "Name", which stores the name of the person. The code then constructs 3 different entries, "da", "Da",and "SM", which areexactly theprefixes of the keywords in the "name" field.

lucene-query query->prefixquery using prefix search