package org.drools.process.core.datatype.impl;



/*

 * Copyright 2005 JBoss Inc

 * 

 * 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.

 */



import org.drools.process.core.datatype.DataType;

import org.drools.process.core.datatype.DataTypeFactory;



/**

 * A data type factory that always returns the same instance of a given class.

 * 

 * @author <a href="mailto:kris_verlaenen@hotmail.com">Kris Verlaenen</a>

 */

public class InstanceDataTypeFactory implements DataTypeFactory {



    private static final long serialVersionUID = 400L;

    

    private Class<?> dataTypeClass;

    private DataType instance;



    public InstanceDataTypeFactory(final Class<?> dataTypeClass) {

        this.dataTypeClass = dataTypeClass;

    }



    public DataType createDataType() {

        if (this.instance == null) {

            try {

                this.instance = (DataType) this.dataTypeClass.newInstance();

            } catch (final IllegalAccessException e) {

                throw new RuntimeException(

                        "Could not create data type for class "

                                + this.dataTypeClass, e);

            } catch (final InstantiationException e) {

                throw new RuntimeException(

                        "Could not create data type for class "

                                + this.dataTypeClass, e);

            }

        }

        return this.instance;

    }



}