MWClassHandle.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.handles;

import org.eclipse.persistence.tools.workbench.mappingsmodel.MWModel;
import org.eclipse.persistence.tools.workbench.mappingsmodel.meta.MWClass;
import org.eclipse.persistence.tools.workbench.utility.node.Node;
import org.eclipse.persistence.tools.workbench.utility.string.StringTools;

import org.eclipse.persistence.oxm.XMLDescriptor;

/**
 * MWClassHandle is used to handle a reference to a MWClass
 * via a type name.
 *
 * This allows us to better control which classes are written out.
 * This also allows us to fabricate classes when a project is read.
 *
 * NOTE: MWClassHandle is DIFFERENT from the other handles.
 * Since many of the other handles are dependent on class handles,
 * we resolve the class handles first, via #resolveClassHandles(),
 * while the other handles are resolved via #postProjectBuild().
 */
public final class MWClassHandle extends MWHandle {

    /**
     * This is the actual type.
     * It is built from the type name, below.
     */
    private volatile MWClass type;

    /**
     * The type name is transient. It is used only to hold its value
     * until resolveClassHandles() is called and we can resolve
     * the actual type. We do not keep it in synch with the type
     * itself because we cannot know when the type has been renamed etc.
     */
    private volatile String typeName;


    // ********** constructors **********

    /**
     * default constructor - for TopLink use only
     */
    private MWClassHandle() {
        super();
    }

    public MWClassHandle(MWModel parent, NodeReferenceScrubber scrubber) {
        super(parent, scrubber);
    }

    public MWClassHandle(MWModel parent, MWClass type, NodeReferenceScrubber scrubber) {
        super(parent, scrubber);
        this.type = type;
    }


    // ********** instance methods **********

    public MWClass getType() {
        return this.type;
    }

    public void setType(MWClass type) {
        this.type = type;
    }

    protected Node node() {
        return getType();
    }

    public MWClassHandle setScrubber(NodeReferenceScrubber scrubber) {
        this.setScrubberInternal(scrubber);
        return this;
    }

    /**
     * Class handles are resolved here - BEFORE all the other handles
     */
    public void resolveClassHandles() {
        super.resolveClassHandles();
        if (this.typeName != null) {
            // the type will never be null - the repository will auto-generate one if necessary
            this.type = this.typeNamed(this.typeName);
            // Ensure typeName is not used by setting it to null....
            this.typeName = null;
        }
    }

    /**
     * Override to delegate comparison to the type itself.
     * If the handles being compared are in a collection that is being sorted,
     * NEITHER type should be null.
     */
    public int compareTo(Object o) {
        return this.type.compareTo(((MWClassHandle) o).type);
    }

    public void toString(StringBuffer sb) {
        if (this.type == null) {
            sb.append("null");
        } else {
            this.type.toString(sb);
        }
    }


    // ********** TopLink methods **********

    public static XMLDescriptor buildDescriptor() {
        XMLDescriptor descriptor = new XMLDescriptor();

        descriptor.setJavaClass(MWClassHandle.class);

        descriptor.addDirectMapping("typeName", "getTypeNameForTopLink", "setTypeNameForTopLink", "type-name/text()");

        return descriptor;
    }

    private String getTypeNameForTopLink() {
        return (this.type == null) ? null : type.getName();
    }

    private void setTypeNameForTopLink(String typeName) {
        this.typeName = typeName;
    }

    // ********** TopLink methods *********

    public static XMLDescriptor legacy60BuildDescriptor() {
        XMLDescriptor descriptor = new XMLDescriptor();

        descriptor.setJavaClass(MWClassHandle.class);

        descriptor.addDirectMapping("typeName", "legacyGetTypeNameForTopLink", "legacySetTypeNameForTopLink", "type-name/text()");

        return descriptor;
    }

    public String legacyGetTypeNameForTopLink() {
        return getType().getName();
    }

    public void legacySetTypeNameForTopLink(String typeName) {
        this.typeName = MWModel.legacyReplaceToplinkDeprecatedClassReferences(typeName);
    }

}