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Tomcat example source code file (

This example Tomcat source code file ( is included in the "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Tomcat tags/keywords

astempty, astempty, class, collection, collection, elexception, elexception, map, object, object, simplenode, string, util

The Tomcat source code

 * 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
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * See the License for the specific language governing permissions and
 * limitations under the License.
/* Generated By:JJTree: Do not edit this line. */

package org.apache.el.parser;

import java.util.Collection;
import java.util.Map;

import javax.el.ELException;

import org.apache.el.lang.EvaluationContext;

 * @author Jacob Hookom []
 * @version $Change: 181177 $$DateTime: 2001/06/26 08:45:09 $$Author: markt $
public final class AstEmpty extends SimpleNode {
    public AstEmpty(int id) {

    public Class getType(EvaluationContext ctx)
            throws ELException {
        return Boolean.class;

    public Object getValue(EvaluationContext ctx)
            throws ELException {
        Object obj = this.children[0].getValue(ctx);
        if (obj == null) {
            return Boolean.TRUE;
        } else if (obj instanceof String) {
            return Boolean.valueOf(((String) obj).length() == 0);
        } else if (obj instanceof Object[]) {
            return Boolean.valueOf(((Object[]) obj).length == 0);
        } else if (obj instanceof Collection) {
            return Boolean.valueOf(((Collection) obj).isEmpty());
        } else if (obj instanceof Map) {
            return Boolean.valueOf(((Map) obj).isEmpty());
        return Boolean.FALSE;

Other Tomcat examples (source code examples)

Here is a short list of links related to this Tomcat source code file:

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