javaconstantnode.java

一个Java持久层类库

package org.hibernate.hql.ast.tree;

import org.hibernate.type.Type;
import org.hibernate.type.TypeFactory;
import org.hibernate.type.LiteralType;
import org.hibernate.util.ReflectHelper;
import org.hibernate.util.StringHelper;
import org.hibernate.engine.SessionFactoryImplementor;
import org.hibernate.dialect.Dialect;
import org.hibernate.QueryException;
import org.hibernate.hql.QueryTranslator;

/**
 * A node representing a static Java constant.
 *
 * @author Steve Ebersole
 */
public class JavaConstantNode extends Node implements ExpectedTypeAwareNode, SessionFactoryAwareNode {

	private SessionFactoryImplementor factory;

	private String constantExpression;
	private Object constantValue;
	private Type heuristicType;

	private Type expectedType;

	public void setText(String s) {
		// for some reason the antlr.CommonAST initialization routines force
		// this method to get called twice.  The first time with an empty string
		if ( StringHelper.isNotEmpty( s ) ) {
			constantExpression = s;
			constantValue = ReflectHelper.getConstantValue( s );
			heuristicType = TypeFactory.heuristicType( constantValue.getClass().getName() );
			super.setText( s );
		}
	}

	public void setExpectedType(Type expectedType) {
		this.expectedType = expectedType;
	}

	public Type getExpectedType() {
		return expectedType;
	}

	public void setSessionFactory(SessionFactoryImplementor factory) {
		this.factory = factory;
	}

	private String resolveToLiteralString(Type type) {
		try {
			LiteralType literalType = ( LiteralType ) type;
			Dialect dialect = factory.getDialect();
			return literalType.objectToSQLString( constantValue, dialect );
		}
		catch ( Throwable t ) {
			throw new QueryException( QueryTranslator.ERROR_CANNOT_FORMAT_LITERAL + constantExpression, t );
		}
	}

	public String getRenderText(SessionFactoryImplementor sessionFactory) {
		Type type = expectedType == null ? heuristicType : expectedType;
		return resolveToLiteralString( type );
	}
}