org.eclipse.persistence.queries.ColumnResult Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of eclipselink Show documentation

EclipseLink build based upon Git transaction f2b9fc5

There is a newer version: 5.0.0-B03

/*
 * Copyright (c) 1998, 2018 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0 which is available at
 * http://www.eclipse.org/legal/epl-2.0,
 * or the Eclipse Distribution License v. 1.0 which is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
 */

// Contributors:
//     Oracle - initial API and implementation from Oracle TopLink
//     08/24/2012-2.5 Guy Pelletier
//       - 350487: JPA 2.1 Specification defined support for Stored Procedure Calls
package org.eclipse.persistence.queries;

import org.eclipse.persistence.internal.helper.DatabaseField;
import org.eclipse.persistence.internal.localization.ExceptionLocalization;
import org.eclipse.persistence.sessions.DatabaseRecord;

/**
 * Purpose:
 * Concrete class to represent the ColumnResult structure as defined by
 * the EJB 3.0 Persistence specification.  This class is a subcomponent of the
 * EntityResult
 *
 * @see EntityResult
 * @author Gordon Yorke
 * @since TopLink Java Essentials
 */

public class ColumnResult extends SQLResult{

    /** Stores the Columns name from the result set */
    protected DatabaseField column;

    public ColumnResult(DatabaseField column){
        if (column == null || column.getName() == null ){
            throw new IllegalArgumentException(ExceptionLocalization.buildMessage("null_value_for_column_result"));
        }
        this.column = column;
    }

    public ColumnResult(String column){
        if (column == null){
            throw new IllegalArgumentException(ExceptionLocalization.buildMessage("null_value_for_column_result"));
        }
        this.column = new DatabaseField(column);
    }

    /**
     * INTERNAL:
     * Convert all the class-name-based settings in this query to actual
     * class-based settings. This method is used when converting a project that
     * has been built with class names to a project with classes.
     * @param classLoader
     */
    public void convertClassNamesToClasses(ClassLoader classLoader){
        super.convertClassNamesToClasses(classLoader);

        column.convertClassNamesToClasses(classLoader);
    }

    public DatabaseField getColumn(){
        return this.column;
    }

    /**
     * INTERNAL:
     * This method is a convenience method for extracting values from Results
     */
    public Object getValueFromRecord(DatabaseRecord record, ResultSetMappingQuery query){
        return record.get(this.column);
    }

    public boolean isColumnResult(){
        return true;
    }

}