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ClassType.javaAPI DocGlassfish v2 API8051Fri May 04 22:35:08 BST 2007com.sun.jdo.spi.persistence.support.sqlstore.query.util.type

ClassType.java

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 * 
 * Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved.
 * 
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License. You can obtain
 * a copy of the License at https://glassfish.dev.java.net/public/CDDL+GPL.html
 * or glassfish/bootstrap/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 * 
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at glassfish/bootstrap/legal/LICENSE.txt.
 * Sun designates this particular file as subject to the "Classpath" exception
 * as provided by Sun in the GPL Version 2 section of the License file that
 * accompanied this code.  If applicable, add the following below the License
 * Header, with the fields enclosed by brackets [] replaced by your own
 * identifying information: "Portions Copyrighted [year]
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 * elects to include this software in this distribution under the [CDDL or GPL
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 * its licensees as provided above.  However, if you add GPL Version 2 code
 * and therefore, elected the GPL Version 2 license, then the option applies
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 */

/*
 * ClassType.java
 *
 * Created on March 8, 2000
 */

package com.sun.jdo.spi.persistence.support.sqlstore.query.util.type;

import java.util.Map;
import java.util.HashMap;
import java.util.List;
import java.util.ArrayList;

import java.lang.reflect.Field;
import java.security.AccessController;
import java.security.PrivilegedAction;

import com.sun.jdo.spi.persistence.utility.FieldTypeEnumeration;
import com.sun.jdo.api.persistence.support.JDOFatalUserException;
import com.sun.jdo.api.persistence.support.JDOFatalInternalException;
import com.sun.jdo.api.persistence.model.Model;
import com.sun.jdo.api.persistence.model.jdo.PersistenceClassElement;
import com.sun.jdo.api.persistence.model.jdo.PersistenceFieldElement;

/**
 *
 * @author  Michael Bouschen
 * @version 0.1
 */
public class ClassType
    extends Type
{
    /**
     * The associated type table.
     */
    protected TypeTable typetab;

    /**
     *
     */
    protected Map fieldInfos;

    /**
     *
     */
    protected PersistenceClassElement pce;

    /**
     *
     */
    public ClassType(String name, Class clazz, int enumType, TypeTable typetab)
    {
        super(name, clazz, enumType);
        this.typetab = typetab;
        this.fieldInfos = new HashMap();
        // get JDO model element if available
        ClassLoader classLoader = clazz.getClassLoader();
        if (classLoader != null)
        {
            try
            {
                this.pce = typetab.model.getPersistenceClass(name, classLoader);
            }
            catch (IllegalArgumentException ex)
            {
                // IllegalArgumentException indicates class loader problem
                throw new JDOFatalUserException(ex.getMessage());
            }
        }
    }

    /**
     *
     */
    public ClassType(String name, Class clazz, TypeTable typetab)
    {
        this(name, clazz, FieldTypeEnumeration.NOT_ENUMERATED, typetab);
    }

    /**
     * Checks the compatibility of this with the specified type.
     * A ClassType object is compatible to
     * errorType, to the type of null (NullType), to itself
     * and to a super class (direct or indirect).
     * @param type type for compatibility check
     * @return true if this is compatible with type;
     * false otherwise.
     * @see Type#isCompatibleWith(Type)
     */
    public boolean isCompatibleWith(Type type)
    {
        boolean result = false;
        if (type instanceof ClassType)
        {
            result = ((ClassType)type).clazz.isAssignableFrom(clazz);
        }
        return result;
    }

    /**
     * Returns whether this represents a type with an
     * defined order.
     * @return true if an order is defined for this;
     * false otherwise.
     */
        public boolean isOrderable()
        {
        Type comparable = typetab.checkType("java.lang.Comparable"); //NOI18N
        return isCompatibleWith(comparable);
        }

    /**
     * Returns true if this is defined as persistence capable class.
     * @return true if this is a persistence capable class;
     * false otherwise.
     */
        public boolean isPersistenceCapable()
        {
        return (pce != null);
        }

    // --------------------
    // Field handling
    // --------------------

    /**
     * Returns an array of fieldInfos for all declared fields.
     */
    public FieldInfo[] getFieldInfos()
    {
        // Initialize the fieldInfos map with the field declared for this class.
        // NOTE, this code does not work for inheritance!
        //Field[] fields = clazz.getDeclaredFields();

        final Class cl = clazz;

        Field[] fields =  (Field[]) AccessController.doPrivileged(new PrivilegedAction() {
                                public Object run () {
                                        return cl.getDeclaredFields();
                                }
                        });

        synchronized(fieldInfos) {
            for (int i = 0; i < fields.length; i++)
            {
                String fieldName = fields[i].getName();
                FieldInfo fieldInfo = (FieldInfo)fieldInfos.get(fieldName);
                if (fieldInfo == null)
                    fieldInfos.put(fieldName, new FieldInfo(fields[i], this));
            }
        }
        return (FieldInfo[])fieldInfos.values().toArray(new FieldInfo[0]);
    }

    /**
     * Return FieldInfo object for the field with the specified name.
     */
    public FieldInfo getFieldInfo(final String fieldName)
    {
        synchronized(fieldInfos) {
            FieldInfo fieldInfo = (FieldInfo)fieldInfos.get(fieldName);
            if (fieldInfo == null)
            {
                // NOTE, no inheritance!
                final Class cl = clazz;
                Field field = (Field) AccessController.doPrivileged(new PrivilegedAction()
                    {
                        public Object run ()
                        {
                            try
                            {
                                return cl.getDeclaredField(fieldName);
                            }
                            catch (NoSuchFieldException ex)
                            {
                                return null; // do nothing, just return null
                            }
                        }
                    });

                if (field != null)
                {
                    fieldInfo = new FieldInfo(field, this);
                    fieldInfos.put(fieldName, fieldInfo);
                }
            }
            return fieldInfo;
        }
    }

    /**
     * Return the list of key field names
     */
    public List getKeyFieldNames()
    {
        if (pce != null)
        {
            PersistenceFieldElement[] persistentFields = pce.getFields();
            List names = new ArrayList();
            for (int i = 0; i < persistentFields.length; i++)
            {
                if (persistentFields[i].isKey())
                    names.add(persistentFields[i].getName());
            }
            return names;
        }
        return null;
    }

}