MWLoginSpecHandle.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.db;

import org.eclipse.persistence.tools.workbench.mappingsmodel.handles.MWHandle;
import org.eclipse.persistence.tools.workbench.utility.node.Node;

import org.eclipse.persistence.descriptors.ClassDescriptor;
import org.eclipse.persistence.oxm.XMLDescriptor;

/**
 * MWLoginSpecHandle is used to isolate the painful bits of code
 * necessary to correctly handle references to MWLoginSpecs.
 * Since a MWLoginSpec is nested within the XML file
 * for a MWDatabase, we need to store a reference to a particular
 * login spec as
 *   - the name of the login spec
 *
 * This causes no end of pain when dealing with TopLink, property
 * change listeners, backward-compatibility, etc.
 *
 * NB: Currently this class is only used by MWDatabase. The model
 * synchronization is performed locally by that class since it holds
 * the child collection of login specs ('loginSpecs') as well as the
 * references to them ('deploymentLoginSpec' and 'developmentLoginSpec').
 * If this handle is ever used in another place in the model, the
 * model synchronization will need to cascade to all model objects
 */
public final class MWLoginSpecHandle extends MWHandle {

    /**
     * This is the actual login spec.
     * It is built from the login spec name, below.
     */
    private volatile MWLoginSpec loginSpec;

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


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

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

    MWLoginSpecHandle(MWDatabase parent, NodeReferenceScrubber scrubber) {
        super(parent, scrubber);
    }

    MWLoginSpecHandle(MWDatabase parent, MWLoginSpec loginSpec, NodeReferenceScrubber scrubber) {
        super(parent, scrubber);
        this.loginSpec = loginSpec;
    }


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

    MWLoginSpec getLoginSpec() {
        return this.loginSpec;
    }

    void setLoginSpec(MWLoginSpec loginSpec) {
        this.loginSpec = loginSpec;
    }

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

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

    public void postProjectBuild() {
        super.postProjectBuild();
        if (this.loginSpecName != null) {
            this.loginSpec = this.getDatabase().loginSpecNamed(this.loginSpecName);
        }
        // Ensure loginSpecName is not used by setting it to null....
        this.loginSpecName = null;
    }


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

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


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

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

        descriptor.setJavaClass(MWLoginSpecHandle.class);

        descriptor.addDirectMapping("loginSpecName", "getLoginSpecNameForToplink", "setLoginSpecNameForToplink", "login-spec-name/text()");

        return descriptor;
    }

    private String getLoginSpecNameForToplink() {
        return (this.loginSpec == null) ? null : this.loginSpec.getName();
    }

    private void setLoginSpecNameForToplink(String loginSpecName) {
        this.loginSpecName = loginSpecName;
    }

}