JavaTypeDeclaration.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.platformsmodel;

import org.eclipse.persistence.tools.workbench.utility.XMLTools;
import org.eclipse.persistence.tools.workbench.utility.node.AbstractNodeModel;
import org.w3c.dom.Node;


/**
 * This class describes a Java type declaration; i.e. a type declaration's
 * Java class and its array depth. The Java class is referenced by name,
 * allowing us to reference classes that are not (or cannot be) loaded.
 *
 * This class's state is immutable - once an instance is built, its state
 * cannot be changed. If you want a different declaration, you will need
 * to build another instance, which isn't all that painful.
 */
public final class JavaTypeDeclaration
    extends AbstractNodeModel
{

    /**
     * store the class as a name, so we can reference classes
     * that are not loaded
     */
    private String javaClassName;

    /**
     * non-array classes have an array depth of zero
     */
    private int arrayDepth;


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

    /**
     * this constructor is called when the type declaration is read from an XML file
     */
    JavaTypeDeclaration(AbstractNodeModel parent, Node node) throws CorruptXMLException {
        super(parent);
        this.read(node);
    }

    /**
     * this constructor is called when the user (or a test case)
     * creates a new type declaration
     */
    JavaTypeDeclaration(AbstractNodeModel parent, String javaClassName, int arrayDepth) {
        super(parent);
        this.javaClassName = javaClassName;
        this.arrayDepth = arrayDepth;
        this.checkState();
    }

    /**
     * this constructor is called when the user (or a test case)
     * creates a new type declaration with an array depth of zero
     */
    JavaTypeDeclaration(AbstractNodeModel parent, String javaClassName) {
        this(parent, javaClassName, 0);
    }


    // ********** accessors **********

    /**
     * Return the "element" name of the Java type declaration.
     */
    public String getJavaClassName() {
        return this.javaClassName;
    }

    /**
     * Return the "array depth" of the Java type declaration.
     */
    public int getArrayDepth() {
        return this.arrayDepth;
    }


    // ********** queries **********

    /**
     * there can be multiple instances of the same Java type
     * declaration, so provide some way of comparing them
     */
    boolean equals(String otherJavaClassName, int otherArrayDepth) {
        return this.javaClassName.equals(otherJavaClassName)
            && this.arrayDepth == otherArrayDepth;
    }

    /**
     * there can be multiple instances of the same Java type
     * declaration, so provide some way of comparing them
     */
    boolean equals(JavaTypeDeclaration other) {
        return this.equals(other.javaClassName, other.arrayDepth);
    }


    // ********** behavior **********

    private void checkState() {
        if ((this.javaClassName == null) || (this.javaClassName.length() == 0)) {
            throw new IllegalStateException("Java class name is required");
        }

        if (this.arrayDepth < 0) {
            throw new IllegalStateException("array depth must be greater than or equal to zero: " + this.arrayDepth);
        }
        if (this.javaClassName.equals(void.class.getName()) && (this.arrayDepth != 0)) {
            throw new IllegalStateException("'void' must have an array depth of zero: " + this.arrayDepth);
        }
    }


    // ********** i/o **********

    private void read(Node node) throws CorruptXMLException {
        if (node == null) {
            throw new CorruptXMLException("missing node");
        }
        this.javaClassName = XMLTools.childTextContent(node, "java-class-name", null);
        this.arrayDepth = XMLTools.childIntContent(node, "array-depth", 0);
        try {
            this.checkState();
        } catch (IllegalStateException ex) {
            throw new CorruptXMLException("illegal state: " + this, ex);
        }
    }

    void write(Node node) {
        XMLTools.addSimpleTextNode(node, "java-class-name", this.javaClassName);
        XMLTools.addSimpleTextNode(node, "array-depth", this.arrayDepth, 0);
    }


    // ********** printing and displaying **********

    /**
     * @see org.eclipse.persistence.tools.workbench.utility.Node#displayString()
     */
    public String displayString() {
        StringBuffer sb = new StringBuffer();
        this.displayStringOn(sb);
        return sb.toString();
    }

    public void displayStringOn(StringBuffer sb) {
        sb.append(this.javaClassName);
        for (int i = this.arrayDepth; i-- > 0; ) {
            sb.append("[]");
        }
    }

    /**
     * @see org.eclipse.persistence.tools.workbench.utility.AbstractModel#toString(StringBuffer)
     */
    public void toString(StringBuffer sb) {
        this.displayStringOn(sb);
    }

}