D-Net

package eu.dnetlib.dhp.common.oozie.property;

import java.io.File;

import java.io.FileOutputStream;

import java.io.OutputStream;

import java.util.Collections;

import java.util.Map;

import java.util.Properties;

import eu.dnetlib.dhp.common.java.PortBindings;

import eu.dnetlib.dhp.common.java.Process;

import eu.dnetlib.dhp.common.java.porttype.PortType;

import org.apache.hadoop.conf.Configuration;

import static eu.dnetlib.dhp.common.WorkflowRuntimeParameters.OOZIE_ACTION_OUTPUT_FILENAME;

/**

 * This process is a solution for setting dynamic properties in oozie workflow definition.

 * 

 * Expects three parameters to be provided: the first 'condition' parameter is boolean value 

 * based on which either first 'inCaseOfTrue' or second 'elseCase' parameter value is set as 

 * the 'result' property.

 *  

 * This can be understood as the: 

 * 

 * condition ? inCaseOfTrue : elseCase

 * 

 * java syntax equivalent.

 * 

 * @author mhorst

 *

 */

public class ConditionalPropertySetter implements Process {

	public static final String PARAM_CONDITION = "condition";

	public static final String PARAM_INCASEOFTRUE = "inCaseOfTrue";

	public static final String PARAM_ELSECASE = "elseCase";

	public static final String OUTPUT_PROPERTY_RESULT = "result";

	@Override

	public Map<String, PortType> getInputPorts() {

		return Collections.emptyMap();

	}

	@Override

	public Map<String, PortType> getOutputPorts() {

		return Collections.emptyMap();

	}

	@Override

	public void run(PortBindings portBindings, Configuration conf,

			Map<String, String> parameters) throws Exception {

		String condition = parameters.get(PARAM_CONDITION);

		if (condition == null) {

			throw new RuntimeException("unable to make decision: " + 

					PARAM_CONDITION + " parameter was not set!");

		}

		Properties props = new Properties();

        props.setProperty(OUTPUT_PROPERTY_RESULT, 

        		Boolean.parseBoolean(condition)?

        				parameters.get(PARAM_INCASEOFTRUE):

        					parameters.get(PARAM_ELSECASE));

        OutputStream os = new FileOutputStream(

        		new File(System.getProperty(OOZIE_ACTION_OUTPUT_FILENAME)));

        try {

        	props.store(os, "");	

        } finally {

        	os.close();	

        }

	}

}