src/main/java/org/apache/commons/ognl/BooleanExpression.java

package org.apache.commons.ognl;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.commons.ognl.enhance.UnsupportedCompilationException;

/**
 * Base class for boolean expressions.
 */
public abstract class BooleanExpression
    extends ExpressionNode
    implements NodeType
{

    private static final long serialVersionUID = 8630306635724834872L;

    protected Class<?> getterClass;

    public BooleanExpression( int id )
    {
        super( id );
    }

    public BooleanExpression( OgnlParser p, int id )
    {
        super( p, id );
    }

    /**
     * {@inheritDoc}
     */
    public Class<?> getGetterClass()
    {
        return getterClass;
    }

    /**
     * {@inheritDoc}
     */
    public Class<?> getSetterClass()
    {
        return null;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public String toGetSourceString( OgnlContext context, Object target )
    {
        try
        {

            Object value = getValueBody( context, target );

            if ( value != null && Boolean.class.isAssignableFrom( value.getClass() ) )
            {
                getterClass = Boolean.TYPE;
            }
            else if ( value != null )
            {
                getterClass = value.getClass();
            }
            else
            {
                getterClass = Boolean.TYPE;
            }

            String ret = super.toGetSourceString( context, target );

            if ( "(false)".equals( ret ) )
            {
                return "false";
            }
            if ( "(true)".equals( ret ) )
            {
                return "true";
            }
            return ret;

        }
        catch ( NullPointerException e )
        {

            // expected to happen in some instances
            e.printStackTrace();

            throw new UnsupportedCompilationException( "evaluation resulted in null expression." );
        }
        catch ( Throwable t )
        {
            throw OgnlOps.castToRuntime( t );
        }
    }
}