asterixdb/asterix-external-data/src/test/java/org/apache/asterix/external/library/CapitalFinderFunction.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.asterix.external.library;

import java.io.InputStream;
import java.util.Properties;

import org.apache.asterix.external.library.java.JObjects.JRecord;
import org.apache.asterix.external.library.java.JObjects.JString;
import org.apache.asterix.external.api.IExternalScalarFunction;
import org.apache.asterix.external.api.IFunctionHelper;
import org.apache.asterix.external.library.java.JTypeTag;

public class CapitalFinderFunction implements IExternalScalarFunction {

    private static Properties capitalList;
    private static final String NOT_FOUND = "NOT_FOUND";
    private JString capital;

    @Override
    public void deinitialize() {
        System.out.println("De-Initialized");
    }

    @Override
    public void evaluate(IFunctionHelper functionHelper) throws Exception {
        JString country = ((JString) functionHelper.getArgument(0));
        JRecord record = (JRecord) functionHelper.getResultObject();
        String capitalCity = capitalList.getProperty(country.getValue(), NOT_FOUND);
        capital.setValue(capitalCity);

        record.setField("country", country);
        record.setField("capital", capital);
        functionHelper.setResult(record);
    }

    @Override
    public void initialize(IFunctionHelper functionHelper) throws Exception {
        InputStream in = CapitalFinderFunction.class.getClassLoader().getResourceAsStream("data/countriesCapitals.txt");
        capitalList = new Properties();
        capitalList.load(in);
        capital = (JString) functionHelper.getObject(JTypeTag.STRING);
    }

}