AGTemporalCalendars.java

package com.franz.agbase.examples;

import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.GregorianCalendar;

import com.franz.agbase.AllegroGraph;
import com.franz.agbase.AllegroGraphConnection;
import com.franz.agbase.AllegroGraphException;
import com.franz.agbase.EncodedLiteral;
import com.franz.agbase.TriplesIterator;

public class AGTemporalCalendars {

    /**
     * Demonstrates converting Gregorian Calendar objects into date-time objects
     * for storage and performing a range query.
     * 
     * @param 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 for this example.
        AllegroGraph ts = ags.renew("gregorian", AGPaths.TRIPLE_STORES);
        
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssZ");
        GregorianCalendar cal = new GregorianCalendar();
        String date;
                
        // Register your namespaces
        ts.registerNamespace("ex","http://example.org/");
        
        // Add some triples to the store using encoded literals
        // Encoded literals are necessary when performing range queries 
        cal.set(1932, Calendar.JANUARY, 1, 0, 0, 1); 
        date = sdf.format(cal.getTime());
        ts.addStatement("!ex:person1","!ex:birthdate", ts.createEncodedLiteral(date,"date-time"));
        cal.set(1948, Calendar.FEBRUARY, 29, 23, 59, 59); 
        date = sdf.format(cal.getTime());
        ts.addStatement("!ex:person2","!ex:birthdate", ts.createEncodedLiteral(date,"date-time"));
        cal.set(1968, Calendar.MARCH, 17, 8, 0, 0); 
        date = sdf.format(cal.getTime());
        ts.addStatement("!ex:person3","!ex:birthdate", ts.createEncodedLiteral(date,"date-time"));
        cal.set(1988, Calendar.APRIL, 3, 9, 0, 0); 
        date = sdf.format(cal.getTime());
        ts.addStatement("!ex:person4","!ex:birthdate", ts.createEncodedLiteral(date,"date-time"));
        cal.set(2007, Calendar.JUNE, 31, 12, 0, 0); 
        date = sdf.format(cal.getTime());
        ts.addStatement("!ex:person5","!ex:birthdate", ts.createEncodedLiteral(date,"date-time"));
        
        // Retrieve triples by matching a range of objects
        cal.set(1980, Calendar.JANUARY, 1, 0, 0, 0); date = sdf.format(cal.getTime());
        EncodedLiteral low = ts.createEncodedLiteral(date,"date-time");
        cal.set(1989, Calendar.DECEMBER, 31, 23, 59, 59); date = sdf.format(cal.getTime());
        EncodedLiteral high = ts.createEncodedLiteral(date,"date-time");
        System.out.println("Retrieving triples for birthdates in the 1980's:");
        TriplesIterator it = ts.getStatements(null, "!ex:birthdate", low, high, null, null);
        AGUtils.showTriples(it);

        // Close the triple store and disconnect from the server
        ts.closeTripleStore();
        ags.disable();      
    }
}

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