package org.apache.torque.om;/* * Copyright 2001-2004 The Apache Software Foundation. * * Licensed under the Apache License, Version 2.0 (the "License") * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * *     http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */import java.io.Serializable;import java.sql.Connection;import org.apache.commons.logging.Log;import org.apache.commons.logging.LogFactory;import org.apache.torque.TorqueException;/** * This class contains attributes and methods that are used by all * business objects within the system. * * @author <a href="mailto:frank.kim@clearink.com">Frank Y. Kim</a> * @author <a href="mailto:jmcnally@collab.net">John D. McNally</a> * @version $Id: BaseObject.java,v 1.20 2005/01/31 19:43:56 tfischer Exp $ */public abstract class BaseObject implements Persistent, Serializable{    /** The constant denoting an unset numeric database identifier. */    public static final int NEW_ID = -1;    /**     * Shared portion of the error message thrown for methods which     * are not implemented.     */    private static final String NOT_IMPLEMENTED            = "Not implemented: Method must be overridden if called";    /** attribute to determine if this object has previously been saved. */    private boolean isNew = true;    /** The unique id for the object which can be used for persistence. */    private ObjectKey primaryKey = null;    /**     * A flag that indicates an object has been modified since it was     * last retrieved from the persistence mechanism.  This flag is     * used to determine if this object should be saved to the     * database.  We initialize it to true to force new objects to be     * saved.     */    private boolean modified = true;    /** Cache the log to avoid looking it up every time its needed. */    private transient Log log = null;    /**     * getter for the object primaryKey.     *     * @return the object primaryKey as an Object     */    public ObjectKey getPrimaryKey()    {        return primaryKey;    }    /**     * Returns whether the object has been modified.     *     * @return True if the object has been modified.     */    public boolean isModified()    {        return modified;    }    /**     * Returns whether the object has ever been saved.  This will     * be false, if the object was retrieved from storage or was created     * and then saved.     *     * @return true, if the object has never been persisted.     */    public boolean isNew()    {        return isNew;    }    /**     * Setter for the isNew attribute.  This method will be called     * by Torque-generated children and Peers.     *     * @param b the state of the object.     */    public void setNew(boolean b)    {        this.isNew = b;    }    /**     * Sets the PrimaryKey for the object.     *     * @param primaryKey The new PrimaryKey for the object.     * @exception TorqueException This method will not throw any exceptions     * but this allows for children to override the method more easily     */    public void setPrimaryKey(String primaryKey) throws TorqueException    {        this.primaryKey = new StringKey(primaryKey);    }    /**     * Sets the PrimaryKey for the object as an Object.     *     * @param primaryKey The new PrimaryKey for the object.     * @exception TorqueException This method will not throw any exceptions     * but this allows for children to override the method more easily     */    public void setPrimaryKey(SimpleKey[] primaryKey) throws TorqueException    {        this.primaryKey = new ComboKey(primaryKey);    }    /**     * Sets the PrimaryKey for the object as an Object.     *     * @param primaryKey The new PrimaryKey for the object.     * @exception TorqueException This method will not throw any exceptions     * but this allows for children to override the method more easily     */    public void setPrimaryKey(ObjectKey primaryKey) throws TorqueException    {        this.primaryKey = primaryKey;    }    /**     * Sets the modified state for the object.     *     * @param m The new modified state for the object.     */    public void setModified(boolean m)    {        modified = m;    }    /**     * Sets the modified state for the object to be false.     */    public void resetModified()    {        modified = false;    }    /**     * Retrieves a field from the object by name. Must be overridden if called.     * BaseObject's implementation will throw an Error.     *     * @param field The name of the field to retrieve.     * @return The retrieved field value     *     */    public Object getByName(String field)    {        throw new Error("BaseObject.getByName: " + NOT_IMPLEMENTED);    }    /**     * Retrieves a field from the object by name passed in     * as a String.  Must be overridden if called.     * BaseObject's implementation will throw an Error.     *     * @param name field name     * @return value of the field     */    public Object getByPeerName(String name)    {        throw new Error("BaseObject.getByPeerName: " + NOT_IMPLEMENTED);    }    /**     * Retrieves a field from the object by position as specified     * in a database schema for example.  Must be overridden if called.     * BaseObject's implementation will throw an Error.     *     * @param pos field position     * @return value of the field     */    public Object getByPosition(int pos)    {        throw new Error("BaseObject.getByPosition: " + NOT_IMPLEMENTED);    }    /**     * Compares this with another <code>BaseObject</code> instance.  If     * <code>obj</code> is an instance of <code>BaseObject</code>, delegates to     * <code>equals(BaseObject)</code>.  Otherwise, returns <code>false</code>.     *     * @param obj The object to compare to.     * @return    Whether equal to the object specified.     */    public boolean equals(Object obj)    {        if (obj != null && obj instanceof BaseObject)        {            return equals((BaseObject) obj);        }        else        {            return false;        }    }    /**     * Compares the primary key of this instance with the key of another.     *     * @param bo The object to compare to.     * @return   Whether the primary keys are equal.     */    public boolean equals(BaseObject bo)    {        if (bo == null)        {            return false;        }        if (this == bo)        {            return true;        }        else if (getPrimaryKey() == null || bo.getPrimaryKey() == null)        {            return false;        }        else        {            return getPrimaryKey().equals(bo.getPrimaryKey());        }    }    /**     * If the primary key is not <code>null</code>, return the hashcode of the     * primary key.  Otherwise calls <code>Object.hashCode()</code>.     *     * @return an <code>int</code> value     */    public int hashCode()    {        ObjectKey ok = getPrimaryKey();        if (ok == null)        {            return super.hashCode();        }        return ok.hashCode();    }    /**     * gets a commons-logging Log based on class name.     *     * @return a <code>Log</code> to write log to.     */    protected Log getLog()    {        if (log == null)        {            log = LogFactory.getLog(getClass().getName());        }        return log;    }    /**     * @see org.apache.torque.om.Persistent#save()     */    public abstract void save() throws Exception;    /**     * @see org.apache.torque.om.Persistent#save(String)     */    public abstract void save(String dbName) throws Exception;    /**     * @see org.apache.torque.om.Persistent#save(Connection)     */    public abstract void save(Connection con) throws Exception;}