/*
* Copyright 2002-2004 The Apache Software Foundation.
*
* Licensed 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.
*/
package org.apache.commons.jexl.parser;
import org.apache.commons.jexl.JexlContext;
import org.apache.commons.jexl.util.Introspector;
import org.apache.commons.jexl.util.introspection.Info;
import org.apache.commons.jexl.util.introspection.VelMethod;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.lang.reflect.Array;
/**
* generalized size() function for all classes we can think of
*
* @author <a href="mailto:geirm@apache.org">Geir Magnusson Jr.</a>
* @author <a href="hw@kremvax.net">Mark H. Wilkinson</a>
* @version $Id: ASTSizeFunction.java,v 1.6 2004/08/15 16:01:12 dion Exp $
*/
public class ASTSizeFunction extends SimpleNode
{
public ASTSizeFunction(int id)
{
super(id);
}
public ASTSizeFunction(Parser p, int id)
{
super(p, id);
}
/** Accept the visitor. **/
public Object jjtAccept(ParserVisitor visitor, Object data)
{
return visitor.visit(this, data);
}
public Object value(JexlContext jc)
throws Exception
{
SimpleNode arg = (SimpleNode) jjtGetChild(0);
Object val = arg.value(jc);
if (val == null)
{
throw new Exception("size() : null arg");
}
return new Integer(ASTSizeFunction.sizeOf(val));
}
public static int sizeOf(Object val)
throws Exception
{
if (val instanceof List)
{
return ((List)val).size();
}
else if (val.getClass().isArray())
{
return Array.getLength(val);
}
else if (val instanceof Map)
{
return ((Map)val).size();
}
else if (val instanceof String)
{
return ((String)val).length();
}
else if (val instanceof Set)
{
return ((Set)val).size();
}
else {
// check if there is a size method on the object that returns an integer
// and if so, just use it
Object[] params = new Object[0];
Info velInfo = new Info("",1,1);
VelMethod vm = Introspector.getUberspect().getMethod(val, "size", params, velInfo);
if (vm != null && vm.getReturnType() == Integer.TYPE)
{
Integer result = (Integer)vm.invoke(val, params);
return result.intValue();
}
else
{
throw new Exception("size() : unknown type : " + val.getClass());
}
}
}
}