Hibernate example source code file (OracleJoinFragment.java)

This example Hibernate source code file (OracleJoinFragment.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Hibernate tags/keywords

character, character, hashset, joinfragment, jointype, oracle9idialect/oracle10gdialect, oraclejoinfragment, oraclejoinfragment, set, string, string, stringbuffer, stringbuffer, unsupportedoperationexception, util

The Hibernate OracleJoinFragment.java source code

/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2008, Red Hat Middleware LLC or third-party contributors as
 * indicated by the @author tags or express copyright attribution
 * statements applied by the authors.  All third-party contributions are
 * distributed under license by Red Hat Middleware LLC.
 *
 * This copyrighted material is made available to anyone wishing to use, modify,
 * copy, or redistribute it subject to the terms and conditions of the GNU
 * Lesser General Public License, as published by the Free Software Foundation.
 *
 * This program 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 this distribution; if not, write to:
 * Free Software Foundation, Inc.
 * 51 Franklin Street, Fifth Floor
 * Boston, MA  02110-1301  USA
 *
 */
package org.hibernate.sql;
import java.util.HashSet;
import java.util.Set;

/**
 * An Oracle-style (theta) join
 *
 * @author Jon Lipsky, Gavin King
 */
public class OracleJoinFragment extends JoinFragment {

	private StringBuffer afterFrom = new StringBuffer();
	private StringBuffer afterWhere = new StringBuffer();

	public void addJoin(String tableName, String alias, String[] fkColumns, String[] pkColumns, JoinType joinType) {

		addCrossJoin( tableName, alias );

		for ( int j = 0; j < fkColumns.length; j++ ) {
			setHasThetaJoins( true );
			afterWhere.append( " and " )
					.append( fkColumns[j] );
			if ( joinType == JoinType.RIGHT_OUTER_JOIN || joinType == JoinType.FULL_JOIN ) afterWhere.append( "(+)" );
			afterWhere.append( '=' )
					.append( alias )
					.append( '.' )
					.append( pkColumns[j] );
			if ( joinType == JoinType.LEFT_OUTER_JOIN || joinType == JoinType.FULL_JOIN ) afterWhere.append( "(+)" );
		}

	}

	public String toFromFragmentString() {
		return afterFrom.toString();
	}

	public String toWhereFragmentString() {
		return afterWhere.toString();
	}

	public void addJoins(String fromFragment, String whereFragment) {
		afterFrom.append( fromFragment );
		afterWhere.append( whereFragment );
	}

	public JoinFragment copy() {
		OracleJoinFragment copy = new OracleJoinFragment();
		copy.afterFrom = new StringBuffer( afterFrom.toString() );
		copy.afterWhere = new StringBuffer( afterWhere.toString() );
		return copy;
	}

	public void addCondition(String alias, String[] columns, String condition) {
		for ( int i = 0; i < columns.length; i++ ) {
			afterWhere.append( " and " )
					.append( alias )
					.append( '.' )
					.append( columns[i] )
					.append( condition );
		}
	}

	public void addCrossJoin(String tableName, String alias) {
		afterFrom.append( ", " )
				.append( tableName )
				.append( ' ' )
				.append( alias );
	}

	public void addCondition(String alias, String[] fkColumns, String[] pkColumns) {
		throw new UnsupportedOperationException();
	}

	public boolean addCondition(String condition) {
		return addCondition( afterWhere, condition );
	}

	public void addFromFragmentString(String fromFragmentString) {
		afterFrom.append( fromFragmentString );
	}

	public void addJoin(String tableName, String alias, String[] fkColumns, String[] pkColumns, JoinType joinType, String on) {
		//arbitrary on clause ignored!!
		addJoin( tableName, alias, fkColumns, pkColumns, joinType );
		if ( joinType == JoinType.INNER_JOIN ) {
			addCondition( on );
		}
		else if ( joinType == JoinType.LEFT_OUTER_JOIN ) {
			addLeftOuterJoinCondition( on );
		}
		else {
			throw new UnsupportedOperationException( "join type not supported by OracleJoinFragment (use Oracle9iDialect/Oracle10gDialect)" );
		}
	}

	/**
	 * This method is a bit of a hack, and assumes
	 * that the column on the "right" side of the
	 * join appears on the "left" side of the
	 * operator, which is extremely wierd if this
	 * was a normal join condition, but is natural
	 * for a filter.
	 */
	private void addLeftOuterJoinCondition(String on) {
		StringBuffer buf = new StringBuffer( on );
		for ( int i = 0; i < buf.length(); i++ ) {
			char character = buf.charAt( i );
			boolean isInsertPoint = OPERATORS.contains( new Character( character ) ) ||
					( character == ' ' && buf.length() > i + 3 && "is ".equals( buf.substring( i + 1, i + 4 ) ) );
			if ( isInsertPoint ) {
				buf.insert( i, "(+)" );
				i += 3;
			}
		}
		addCondition( buf.toString() );
	}

	private static final Set OPERATORS = new HashSet();

	static {
		OPERATORS.add( new Character( '=' ) );
		OPERATORS.add( new Character( '<' ) );
		OPERATORS.add( new Character( '>' ) );
	}
}