org.datanucleus.store.rdbms.mapping.java.ObjectMapping Maven / Gradle / Ivy

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Plugin for DataNucleus providing persistence to RDBMS datastores.

There is a newer version: 6.0.7

/**********************************************************************
Copyright (c) 2005 Andy Jefferson and others. All rights reserved.
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.


Contributors:
    ...
***********************************************************************/
package org.datanucleus.store.rdbms.mapping.java;

import org.datanucleus.ClassNameConstants;

/**
 * Mapping for Object fields.
 * An Object field can represent two things
 * 
 * An object of a series of possible PC types ("implementation-classes") and each implementation type is
 * represented in the datastore by a FK to the PC table
 * An object of a series of possible non-PC types (e.g String, Long, Double etc) and each implementation type
 * is represented in the datastore by a separate column
 * 
 */
public class ObjectMapping extends ReferenceMapping
{
    /**
     * Accessor for the Java type being represented.
     * @return java.lang.Object
     */
    public Class getJavaType()
    {
        return Object.class;
    }

    /**
     * Accessor for the name of the java-type actually used when mapping the particular datastore
     * field. Returns Serializable since the object needs to be serialisable
     * @param index requested datastore field index.
     * @return the name of java-type for the requested datastore field.
     */
    public String getJavaTypeForDatastoreMapping(int index)
    {
        return ClassNameConstants.JAVA_IO_SERIALIZABLE;
    }
}