# AGFreetextSearch.java

`package com.franz.agbase.examples;
import com.franz.agbase.*;
public class AGFreetextSearch {
/**
* Demonstrates some basics of Freetext search
*
* @param args unused
* @throws AllegroGraphException
*/
public static void main(String[] args) throws AllegroGraphException {
// Connect to server, which must already be running.
AllegroGraphConnection ags = new AllegroGraphConnection();
try {
ags.enable();
} catch (Exception e) {
throw new AllegroGraphException("Server connection problem", e);
}
// Create a fresh triple store
AllegroGraph ts = ags.renew("freetextsearch", AGPaths.TRIPLE_STORES);
// Register a namespace
ts.registerNamespace("ex", "http://example.org/");
// Register any predicates whose objects are to be searched.
// Only triples added or loaded after the registration will
// be included in the index.
ts.registerFreetextPredicate("<http://www.w3.org/2000/01/rdf-schema#comment>");
ts.registerFreetextPredicate("!ex:notes");
// Add some triples to the store. Triples involving registered predicates will be
// indexed for free-text search, others will not.
ts.addStatement("!ex:jans", "!rdfs:comment", "\"Born in Emmen in the Netherlands\"");
ts.addStatement("!ex:gary", "!rdfs:comment", "\"Born in Springfield in the USA\"");
ts.addStatement("!ex:henk", "!rdfs:label", "\"Born in Emmermeer in the Netherlands\"");
ts.addStatement("!ex:alice", "!ex:notes", "\"wasn't born in Wonderland.\"");
ts.addStatement("!ex:bob", "!ex:notes", "\"your uncle.\"");
ts.addStatement("!ex:fred", "!ex:notes", "\"Lives in Bedrock.\"");
ts.addStatement("!ex:stanley", "!ex:notes", "\"Dr. Livingstone I presume?\"");
ts.addStatement("!ex:fibonacci", "!ex:notes", "\"fib(n+2) = fib(n+1) + fib(n)\"");
// Search for statements whose object contains the word born -- note that
// search is case insensitive
String query = "'born'";
System.out.println("Search: " + query);
TriplesIterator cc = ts.getFreetextStatements(query);
AGUtils.showTriples(cc);
// Search for statements whose object contains words emmen and born
query = "(and 'emmen' 'born')";
System.out.println("Search: " + query);
cc = ts.getFreetextStatements(query);
AGUtils.showTriples(cc);
// Search for statements whose object contains words Wonderland or Bedrock
query = "(or 'Wonderland' 'Bedrock')";
System.out.println("Search: " + query);
cc = ts.getFreetextStatements(query);
AGUtils.showTriples(cc);
// Words of 2 chars or less are not indexed
query = "(or 'in' 'a')";
System.out.println("Search: " + query);
cc = ts.getFreetextStatements(query);
AGUtils.showTriples(cc);
// Some common words, called "stop words", are also not indexed
query = "'the'";
System.out.println("Search: " + query);
cc = ts.getFreetextStatements(query);
AGUtils.showTriples(cc);
// Some characters, such as '(' and ')' delimit tokens.
// Note: 'fib(x)' will tokenize as "fib" and "x", and "x"
// will be ignored having < 2 letters, so it's really a
// search for 'fib'. Try searching for 'fib(xxx)' and
// note the different results.
query = "'fib(x)'";
System.out.println("Search: " + query);
cc = ts.getFreetextStatements(query);
AGUtils.showTriples(cc);
// Match a single character with '?'
query = "'Liv??'";
System.out.println("Search: " + query);
cc = ts.getFreetextStatements(query);
AGUtils.showTriples(cc);
// Match a sequence of characters with '*'
query = "'Liv*'";
System.out.println("Search: " + query);
cc = ts.getFreetextStatements(query);
AGUtils.showTriples(cc);
// Search for subjects whose object contains Wonderland or Bedrock
query = "(or 'Wonderland' 'Bedrock')";
ValueSetIterator it = ts.getFreetextUniqueSubjects(query);
System.out.println("Subjects matching search: " + query);
AGUtils.showResults(it);
// Close the triple store and disconnect from the server
ts.closeTripleStore();
ags.disable();
}
}
`

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