MaxExample.java

/*
 * Copyright 2017 Crown Copyright
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package uk.gov.gchq.gaffer.doc.operation;

import uk.gov.gchq.gaffer.data.element.Element;
import uk.gov.gchq.gaffer.data.element.comparison.ElementPropertyComparator;
import uk.gov.gchq.gaffer.data.element.function.ElementTransformer;
import uk.gov.gchq.gaffer.data.elementdefinition.view.View;
import uk.gov.gchq.gaffer.data.elementdefinition.view.ViewElementDefinition;
import uk.gov.gchq.gaffer.doc.operation.function.ExampleScoreFunction;
import uk.gov.gchq.gaffer.operation.OperationChain;
import uk.gov.gchq.gaffer.operation.OperationException;
import uk.gov.gchq.gaffer.operation.data.EntitySeed;
import uk.gov.gchq.gaffer.operation.impl.compare.Max;
import uk.gov.gchq.gaffer.operation.impl.get.GetElements;

public class MaxExample extends OperationExample {
    public MaxExample() {
        super(Max.class);
    }

    public static void main(final String[] args) throws OperationException {
        new MaxExample().run();
    }

    @Override
    public void runExamples() {
        maxCount();
        maxCountAndTransientProperty();
    }

    public Element maxCount() {
        // ---------------------------------------------------------
        final OperationChain<Element> opChain = new OperationChain.Builder()
                .first(new GetElements.Builder()
                        .input(new EntitySeed(1), new EntitySeed(2))
                        .build())
                .then(new Max.Builder()
                        .comparators(new ElementPropertyComparator.Builder()
                                .groups("entity", "edge")
                                .property("count")
                                .build())
                        .build())
                .build();
        // ---------------------------------------------------------

        return runExample(opChain);
    }

    public Element maxCountAndTransientProperty() {
        // ---------------------------------------------------------
        final OperationChain<Element> opChain = new OperationChain.Builder()
                .first(new GetElements.Builder()
                        .input(new EntitySeed(1), new EntitySeed(2))
                        .view(new View.Builder()
                                .entity("entity", new ViewElementDefinition.Builder()
                                        .transientProperty("score", Integer.class)
                                        .transformer(new ElementTransformer.Builder()
                                                .select("VERTEX", "count")
                                                .execute(new ExampleScoreFunction())
                                                .project("score")
                                                .build())
                                        .build())
                                .edge("edge", new ViewElementDefinition.Builder()
                                        .transientProperty("score", Integer.class)
                                        .transformer(new ElementTransformer.Builder()
                                                .select("DESTINATION", "count")
                                                .execute(new ExampleScoreFunction())
                                                .project("score")
                                                .build())
                                        .build())
                                .build())
                        .build())
                .then(new Max.Builder()
                        .comparators(
                                new ElementPropertyComparator.Builder()
                                        .groups("entity", "edge")
                                        .property("count")
                                        .reverse(false)
                                        .build(),
                                new ElementPropertyComparator.Builder()
                                        .groups("entity", "edge")
                                        .property("score")
                                        .reverse(false)
                                        .build()
                        )
                        .build())
                .build();
        // ---------------------------------------------------------

        return runExample(opChain);
    }
}