001: /*
002: * The Apache Software License, Version 1.1
003: *
004: * Copyright (c) 1999 The Apache Software Foundation. All rights
005: * reserved.
006: *
007: * Redistribution and use in source and binary forms, with or without
008: * modification, are permitted provided that the following conditions
009: * are met:
010: *
011: * 1. Redistributions of source code must retain the above copyright
012: * notice, this list of conditions and the following disclaimer.
013: *
014: * 2. Redistributions in binary form must reproduce the above copyright
015: * notice, this list of conditions and the following disclaimer in
016: * the documentation and/or other materials provided with the
017: * distribution.
018: *
019: * 3. The end-user documentation included with the redistribution, if
020: * any, must include the following acknowlegement:
021: * "This product includes software developed by the
022: * Apache Software Foundation (http://www.apache.org/)."
023: * Alternately, this acknowlegement may appear in the software itself,
024: * if and wherever such third-party acknowlegements normally appear.
025: *
026: * 4. The names "The Jakarta Project", "Tomcat", and "Apache Software
027: * Foundation" must not be used to endorse or promote products derived
028: * from this software without prior written permission. For written
029: * permission, please contact apache@apache.org.
030: *
031: * 5. Products derived from this software may not be called "Apache"
032: * nor may "Apache" appear in their names without prior written
033: * permission of the Apache Group.
034: *
035: * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
036: * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
037: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
038: * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
039: * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
040: * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
041: * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
042: * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
043: * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
044: * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
045: * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
046: * SUCH DAMAGE.
047: * ====================================================================
048: *
049: * This software consists of voluntary contributions made by many
050: * individuals on behalf of the Apache Software Foundation. For more
051: * information on the Apache Software Foundation, please see
052: * <http://www.apache.org/>.
053: *
054: */
055:
056: package org.apache.commons.el;
057:
058: /**
059: *
060: * <p>An expression representing a boolean literal value
061: *
062: * @author Nathan Abramson - Art Technology Group
063: * @version $Change: 181177 $$DateTime: 2001/06/26 08:45:09 $$Author: luehe $
064: **/
065:
066: public class BooleanLiteral extends Literal {
067: //-------------------------------------
068: // Member variables
069: //-------------------------------------
070:
071: public static final BooleanLiteral TRUE = new BooleanLiteral("true");
072: public static final BooleanLiteral FALSE = new BooleanLiteral(
073: "false");
074:
075: //-------------------------------------
076: /**
077: *
078: * Constructor
079: **/
080: public BooleanLiteral(String pToken) {
081: super (getValueFromToken(pToken));
082: }
083:
084: //-------------------------------------
085: /**
086: *
087: * Parses the given token into the literal value
088: **/
089: static Object getValueFromToken(String pToken) {
090: return ("true".equals(pToken)) ? Boolean.TRUE : Boolean.FALSE;
091: }
092:
093: //-------------------------------------
094: // Expression methods
095: //-------------------------------------
096: /**
097: *
098: * Returns the expression in the expression language syntax
099: **/
100: public String getExpressionString() {
101: return (getValue() == Boolean.TRUE) ? "true" : "false";
102: }
103:
104: //-------------------------------------
105: }
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