eu.esdihumboldt.hale.common.align.transformation.function.impl.AbstractTransformationFunction.java Source code

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Here is the source code for eu.esdihumboldt.hale.common.align.transformation.function.impl.AbstractTransformationFunction.java

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/*
 * Copyright (c) 2012 Data Harmonisation Panel
 * 
 * All rights reserved. This program and the accompanying materials are made
 * available under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 3 of the License,
 * or (at your option) any later version.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with this distribution. If not, see <http://www.gnu.org/licenses/>.
 * 
 * Contributors:
 *     HUMBOLDT EU Integrated Project #030962
 *     Data Harmonisation Panel <http://www.dhpanel.eu>
 */

package eu.esdihumboldt.hale.common.align.transformation.function.impl;

import java.text.MessageFormat;

import com.google.common.collect.ListMultimap;
import com.google.common.collect.Multimaps;

import eu.esdihumboldt.hale.common.align.model.ParameterValue;
import eu.esdihumboldt.hale.common.align.transformation.engine.TransformationEngine;
import eu.esdihumboldt.hale.common.align.transformation.function.ExecutionContext;
import eu.esdihumboldt.hale.common.align.transformation.function.TransformationException;
import eu.esdihumboldt.hale.common.align.transformation.function.TransformationFunction;
import eu.esdihumboldt.hale.common.core.io.Value;

/**
 * Transformation function base class
 * 
 * @param <E> the transformation engine type
 * 
 * @author Simon Templer
 */
public abstract class AbstractTransformationFunction<E extends TransformationEngine>
        implements TransformationFunction<E> {

    private ListMultimap<String, ParameterValue> parameters;
    private ExecutionContext executionContext;

    /**
     * @see TransformationFunction#setParameters(ListMultimap)
     */
    @Override
    public void setParameters(ListMultimap<String, ParameterValue> parameters) {
        this.parameters = (parameters == null) ? (null) : (Multimaps.unmodifiableListMultimap(parameters));
    }

    /**
     * Get the function parameters
     * 
     * @return the parameters, may be <code>null</code> if there are none
     */
    public ListMultimap<String, ParameterValue> getParameters() {
        return parameters;
    }

    /**
     * @see TransformationFunction#setExecutionContext(ExecutionContext)
     */
    @Override
    public void setExecutionContext(ExecutionContext executionContext) {
        this.executionContext = executionContext;
    }

    /**
     * Get the current execution context.
     * 
     * @return the executionContext the execution context
     */
    public ExecutionContext getExecutionContext() {
        return executionContext;
    }

    /**
     * Checks if a certain parameter is defined at least a given number of
     * times. Throws a {@link TransformationException} otherwise.
     * 
     * @param parameterName the parameter name
     * @param minCount the minimum count the parameter must be present
     * @throws TransformationException if the parameter doesn't exist the given
     *             number of times
     */
    public void checkParameter(String parameterName, int minCount) throws TransformationException {
        if (parameters == null || parameters.get(parameterName) == null
                || parameters.get(parameterName).size() < minCount) {
            if (minCount == 1) {
                throw new TransformationException(
                        MessageFormat.format("Mandatory parameter {0} not defined", parameterName));
            } else {
                throw new TransformationException(MessageFormat.format("Parameter {0} is needed at least {1} times",
                        parameterName, minCount));
            }
        }
    }

    /**
     * Get the first parameter defined with the given parameter name. Throws a
     * {@link TransformationException} if such a parameter doesn't exist.
     * 
     * @param parameterName the parameter name
     * @return the parameter value
     * @throws TransformationException if a parameter with the given name
     *             doesn't exist
     */
    public ParameterValue getParameterChecked(String parameterName) throws TransformationException {
        if (getParameters() == null || getParameters().get(parameterName) == null
                || getParameters().get(parameterName).isEmpty()) {
            throw new TransformationException(
                    MessageFormat.format("Mandatory parameter {0} not defined", parameterName));
        }

        return getParameters().get(parameterName).get(0);
    }

    /**
     * Get the first parameter defined with the given parameter name. If no such
     * parameter exists, the given default value is returned.
     * 
     * @param parameterName the parameter name
     * @param defaultValue the default value for the parameter
     * @return the parameter value, or the default if none is specified
     */
    public ParameterValue getOptionalParameter(String parameterName, Value defaultValue) {
        if (getParameters() == null || getParameters().get(parameterName) == null
                || getParameters().get(parameterName).isEmpty()
                || getParameters().get(parameterName).get(0).isEmpty()) {
            return new ParameterValue(defaultValue);
        }

        return getParameters().get(parameterName).get(0);
    }

}