Main.java example

Explorer
cayenne-master
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package org.apache.cayenne.tutorial;

import static org.apache.cayenne.exp.ExpressionFactory.exp;

import java.util.Calendar;
import java.util.GregorianCalendar;
import java.util.List;

import org.apache.cayenne.Cayenne;
import org.apache.cayenne.ObjectContext;
import org.apache.cayenne.configuration.server.ServerRuntime;
import org.apache.cayenne.exp.Expression;
import org.apache.cayenne.query.SelectQuery;
import org.apache.cayenne.tutorial.persistent.Artist;
import org.apache.cayenne.tutorial.persistent.Gallery;
import org.apache.cayenne.tutorial.persistent.Painting;

public class Main {

    public static void main(String[] args) {

        // starting Cayenne
        ServerRuntime cayenneRuntime = ServerRuntime.builder()
                .addConfig("cayenne-project.xml")
                .build();

        // getting a hold of ObjectContext
        ObjectContext context = cayenneRuntime.newContext();

        newObjectsTutorial(context);
        selectTutorial(context);
        deleteTutorial(context);
    }

    static void newObjectsTutorial(ObjectContext context) {

        // creating new Artist
        Artist picasso = context.newObject(Artist.class);
        picasso.setName("Pablo Picasso");
        picasso.setDateOfBirthString("18811025");

        // Creating other objects
        Gallery metropolitan = context.newObject(Gallery.class);
        metropolitan.setName("Metropolitan Museum of Art");

        Painting girl = context.newObject(Painting.class);
        girl.setName("Girl Reading at a Table");

        Painting stein = context.newObject(Painting.class);
        stein.setName("Gertrude Stein");

        // connecting objects together via relationships
        picasso.addToPaintings(girl);
        picasso.addToPaintings(stein);

        girl.setGallery(metropolitan);
        stein.setGallery(metropolitan);

        // saving all the changes above
        context.commitChanges();
    }

    static void selectTutorial(ObjectContext context) {
        // SelectQuery examples
        SelectQuery<Painting> select1 = SelectQuery.query(Painting.class, null);
        List<Painting> paintings1 = context.select(select1);

        Expression qualifier2 = Painting.NAME.likeIgnoreCase("gi%");
        SelectQuery<Painting> select2 = SelectQuery.query(Painting.class, qualifier2);
        List<Painting> paintings2 = context.select(select2);

        Calendar c = new GregorianCalendar();
        c.set(c.get(Calendar.YEAR) - 100, 0, 1, 0, 0, 0);

        Expression qualifier3 = exp("artist.dateOfBirth < $date", c.getTime());
        SelectQuery<Painting> select3 = SelectQuery.query(Painting.class, qualifier3);
        List<Painting> paintings3 = context.select(select3);
    }

    static void deleteTutorial(ObjectContext context) {
        // Delete object examples
        Expression qualifier = Artist.NAME.eq("Pablo Picasso");
        SelectQuery<Artist> selectToDelete = SelectQuery.query(Artist.class, qualifier);
        Artist picasso = (Artist) Cayenne.objectForQuery(context, selectToDelete);

        if (picasso != null) {
            context.deleteObjects(picasso);
            context.commitChanges();
        }
    }
}