CLExternalClassDescription.java

/*******************************************************************************
 * Copyright (c) 1998, 2015 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 v1.0 and Eclipse Distribution License v. 1.0
 * which accompanies this distribution.
 * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * Contributors:
 *     Oracle - initial API and implementation from Oracle TopLink
******************************************************************************/
package org.eclipse.persistence.tools.workbench.mappingsmodel.spi.meta.classloader;

import org.eclipse.persistence.tools.workbench.mappingsmodel.spi.meta.ExternalClass;
import org.eclipse.persistence.tools.workbench.mappingsmodel.spi.meta.ExternalClassDescription;
import org.eclipse.persistence.tools.workbench.mappingsmodel.spi.meta.ExternalClassNotFoundException;
import org.eclipse.persistence.tools.workbench.utility.ClassTools;
import org.eclipse.persistence.tools.workbench.utility.string.StringTools;


/**
 * Derive most of the type's state from the class name.
 * Build the external class only on demand.
 */
final class CLExternalClassDescription
    implements ExternalClassDescription
{

    /** The name of the type. */
    private final String name;

    /** The classpath entry that contains the class file corresponding to the type. */
    private final String classpathEntry;

    /** The repository used by the external class description to find other class descriptions. */
    private final AbstractCLExternalClassRepository repository;

    /** The external class corresponding to the type. This is null until needed. */
    private ExternalClass externalClass;        // pseudo-final


    // ********** Constructors **********

    /**
     * Package-accessible constructor.
     */
    CLExternalClassDescription(String name, String classpathEntry, AbstractCLExternalClassRepository repository) {
        super();
        this.name = name;
        this.classpathEntry = classpathEntry;
        this.repository = repository;
    }

    /**
     * Package-accessible constructor.
     * Used for "array" types that do not have a classpath entry.
     */
    CLExternalClassDescription(String name, AbstractCLExternalClassRepository repository) {
        this(name, "", repository);
    }


    // ********** ExternalClassDescription implementation **********

    /**
     * @see org.eclipse.persistence.tools.workbench.mappingsmodel.spi.meta.ExternalClassDescription#getArrayDepth()
     */
    public int getArrayDepth() {
        return ClassTools.arrayDepthForClassNamed(this.name);
    }

    /**
     * @see org.eclipse.persistence.tools.workbench.mappingsmodel.spi.meta.ClassDescription#getAdditionalInfo()
     */
    public String getAdditionalInfo() {
        return this.classpathEntry;
    }

    /**
     * @see org.eclipse.persistence.tools.workbench.mappingsmodel.spi.meta.ExternalClassDescription#getElementTypeName()
     */
    public String getElementTypeName() {
        return ClassTools.elementTypeNameForClassNamed(this.name);
    }

    /**
     * @see org.eclipse.persistence.tools.workbench.mappingsmodel.spi.meta.ExternalClassDescription#getExternalClass()
     */
    public synchronized ExternalClass getExternalClass() throws ExternalClassNotFoundException {
        if (this.externalClass == null) {
            this.externalClass = this.buildExternalClass();
        }
        return this.externalClass;
    }

    /**
     * @see org.eclipse.persistence.tools.workbench.mappingsmodel.spi.meta.ClassDescription#getName()
     */
    public String getName() {
        return this.name;
    }

    /**
     * @see org.eclipse.persistence.tools.workbench.mappingsmodel.spi.meta.ExternalClassDescription#isSynthetic()
     */
    public boolean isSynthetic() {
        return ClassTools.classNamedIsAnonymous(this.name);
    }


    // ********** standard methods **********

    public String toString() {
        return StringTools.buildToStringFor(this, this.getName());
    }


    // ********** package-accessible methods **********

    ExternalClassDescription classDescriptionFor(Class javaClass) {
        return this.repository.getClassDescriptionFor(javaClass);
    }


    // ********** internal methods **********

    /**
     * Build an external class corresponding to the external class description.
     */
    private ExternalClass buildExternalClass() throws ExternalClassNotFoundException {
        // external array *types* are supported; but we do *not* support external array *classes*
        if (this.getArrayDepth() != 0) {
            throw new IllegalStateException();
        }
        return new CLExternalClass(this.repository.loadClass(this.name), this);
    }

}