com.avaje.ebeaninternal.server.deploy.meta.DeployTableJoinColumn Maven / Gradle / Ivy

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/**
 * Copyright (C) 2006  Robin Bygrave
 * 
 * This file is part of Ebean.
 * 
 * Ebean is free software; you can redistribute it and/or modify it 
 * under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or
 * (at your option) any later version.
 *  
 * Ebean is distributed in the hope that it will be useful, but 
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with Ebean; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA  
 */
package com.avaje.ebeaninternal.server.deploy.meta;

import javax.persistence.JoinColumn;

import com.avaje.ebeaninternal.server.deploy.BeanProperty;
import com.avaje.ebeaninternal.server.deploy.BeanTable;

/**
 * A join pair of local and foreign properties.
 */
public class DeployTableJoinColumn {

	/**
	 * The local database column name.
	 */
	String localDbColumn;

	/**
	 * The foreign database column name.
	 */
	String foreignDbColumn;

	boolean insertable;
	
	boolean updateable;
	
	/**
	 * Construct when automatically determining the join.
	 * 
	 * Assume that we want the foreign key to be insertable and updateable.
	 * 
	 */
	public DeployTableJoinColumn(String localDbColumn, String foreignDbColumn) {
		this(localDbColumn, foreignDbColumn, true, true);
	}
	    
	/**
	 * Construct with explicit insertable and updateable flags.
	 */
	public DeployTableJoinColumn(String localDbColumn, String foreignDbColumn, boolean insertable, boolean updateable) {
		this.localDbColumn = nullEmptyString(localDbColumn);
		this.foreignDbColumn = nullEmptyString(foreignDbColumn);
		this.insertable = insertable;
		this.updateable = updateable;
	}
    
    public DeployTableJoinColumn(boolean order, JoinColumn jc, BeanTable beanTable) {
    	this(jc.referencedColumnName(), jc.name(), jc.insertable(), jc.updatable());
    	setReferencedColumn(beanTable);
    	if (!order){
    		reverse();
    	}
    }

    private void setReferencedColumn(BeanTable beanTable){
    	if (localDbColumn == null){
    		BeanProperty[] idProperties = beanTable.getIdProperties();
    		if (idProperties.length == 1){
    			localDbColumn = idProperties[0].getDbColumn();
    		}
    	}
    }
    
    /**
     * Reverse the direction of the join.
     */
    public DeployTableJoinColumn reverse() {
    	String temp = localDbColumn;
    	localDbColumn = foreignDbColumn;
    	foreignDbColumn = temp;
    	return this;
    }

    /**
     * Helper method to null out empty strings.
     */
	private String nullEmptyString(String s){
		if ("".equals(s)){
			return null;
		}
		return s;
	}
	
	
	public DeployTableJoinColumn copy(boolean reverse) {
		// Note that the insertable and updateable are just copied 
		// which may not always be the correct thing to do
		// but will leave it like this for now
		if (reverse){
			return new DeployTableJoinColumn(foreignDbColumn, localDbColumn, insertable, updateable);
			
		} else {
			return new DeployTableJoinColumn(localDbColumn, foreignDbColumn, insertable, updateable);			
		}
	}

	public String toString() {
		return localDbColumn + " = " + foreignDbColumn;
	}

	/**
	 * Return true if either the local or foreign column is null.
	 * 
	 * Both columns need to be defined. If one is null then typically it is
	 * derived as the primary key column.
	 * 
	 */
	public boolean hasNullColumn() {
		return localDbColumn == null || foreignDbColumn == null;
	}

	/**
	 * When only ONE column has been set by deployment information return that one.
	 * 
	 * Used with hasNullColumn() to set the foreignDbColumn for OneToMany joins.
	 * 
	 */
	public String getNonNullColumn() {
		if (localDbColumn == null && foreignDbColumn == null) {
			throw new IllegalStateException("expecting only one null column?");
			
		} else if (localDbColumn != null && foreignDbColumn != null) {
			throw new IllegalStateException("expecting one null column?");			
		}
		if (localDbColumn != null) {
			return localDbColumn;
		} else {			
			return foreignDbColumn;
		}
	}

	/**
	 * Return true if this column should be insertable.
	 */
	public boolean isInsertable() {
		return insertable;
	}

	/**
	 * Return true if this column should be updateable.
	 */
	public boolean isUpdateable() {
		return updateable;
	}

	/**
	 * Return the foreign database column name.
	 */
	public String getForeignDbColumn() {
		return foreignDbColumn;
	}

	/**
	 * Set the foreign database column name.
	 * 
	 * Used when this is derived from Primary Key and not set explicitly in the
	 * deployment information.
	 * 
	 */
	public void setForeignDbColumn(String foreignDbColumn) {
		this.foreignDbColumn = foreignDbColumn;
	}

	/**
	 * Return the local database column name.
	 */
	public String getLocalDbColumn() {
		return localDbColumn;
	}

	/**
	 * Set the local database column name.
	 */
	public void setLocalDbColumn(String localDbColumn) {
		this.localDbColumn = localDbColumn;
	}

}