EJBQLToSQL.java

package strimillinn.xperimental;

import static strimillinn.core.StrimillinnCore.*;

import org.apache.cayenne.access.DataNode;
import org.apache.cayenne.access.translator.ejbql.EJBQLTranslationContext;
import org.apache.cayenne.access.translator.ejbql.EJBQLTranslatorFactory;
import org.apache.cayenne.configuration.server.ServerRuntime;
import org.apache.cayenne.ejbql.EJBQLBaseVisitor;
import org.apache.cayenne.ejbql.EJBQLCompiledExpression;
import org.apache.cayenne.ejbql.EJBQLExpression;
import org.apache.cayenne.ejbql.EJBQLExpressionVisitor;
import org.apache.cayenne.query.EJBQLQuery;

public class EJBQLToSQL {

	/**
	 * @return The given EJBQL compiled to SQL
	 */
	private static String ejbqlToSQL( ServerRuntime runtime, String ejbqlString ) {
		final EJBQLQuery ejbqlQuery = new EJBQLQuery( ejbqlString );
		final DataNode dataNode = runtime.getDataDomain().getDefaultNode();
		final EJBQLCompiledExpression compiledExpression = ejbqlQuery.getExpression( dataNode.getEntityResolver() );
		final EJBQLTranslatorFactory translatorFactory = dataNode.getAdapter().getEjbqlTranslatorFactory();
		final EJBQLTranslationContext context = new EJBQLTranslationContext( dataNode.getEntityResolver(), ejbqlQuery, compiledExpression, translatorFactory, dataNode.getAdapter().getQuotingStrategy() );

		compiledExpression.getExpression().visit( new EJBQLBaseVisitor( false ) {

			@Override
			public boolean visitSelect( EJBQLExpression expression ) {
				EJBQLExpressionVisitor visitor = translatorFactory.getSelectTranslator( context );
				expression.visit( visitor );
				return false;
			}

			@Override
			public boolean visitDelete( EJBQLExpression expression ) {
				EJBQLExpressionVisitor visitor = translatorFactory.getDeleteTranslator( context );
				expression.visit( visitor );
				return false;
			}

			@Override
			public boolean visitUpdate( EJBQLExpression expression ) {
				EJBQLExpressionVisitor visitor = translatorFactory.getUpdateTranslator( context );
				expression.visit( visitor );
				return false;
			}
		} );

		return context.getQuery().getDefaultTemplate();
	}

	public static void main( String[] args ) {
		System.out.println( ejbqlToSQL( serverRuntime(), "select u from User u" ) );
	}
}