01: /*
02: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
03: *
04: * Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved.
05: *
06: * Portions Copyright Apache Software Foundation.
07: *
08: * The contents of this file are subject to the terms of either the GNU
09: * General Public License Version 2 only ("GPL") or the Common Development
10: * and Distribution License("CDDL") (collectively, the "License"). You
11: * may not use this file except in compliance with the License. You can obtain
12: * a copy of the License at https://glassfish.dev.java.net/public/CDDL+GPL.html
13: * or glassfish/bootstrap/legal/LICENSE.txt. See the License for the specific
14: * language governing permissions and limitations under the License.
15: *
16: * When distributing the software, include this License Header Notice in each
17: * file and include the License file at glassfish/bootstrap/legal/LICENSE.txt.
18: * Sun designates this particular file as subject to the "Classpath" exception
19: * as provided by Sun in the GPL Version 2 section of the License file that
20: * accompanied this code. If applicable, add the following below the License
21: * Header, with the fields enclosed by brackets [] replaced by your own
22: * identifying information: "Portions Copyrighted [year]
23: * [name of copyright owner]"
24: *
25: * Contributor(s):
26: *
27: * If you wish your version of this file to be governed by only the CDDL or
28: * only the GPL Version 2, indicate your decision by adding "[Contributor]
29: * elects to include this software in this distribution under the [CDDL or GPL
30: * Version 2] license." If you don't indicate a single choice of license, a
31: * recipient has the option to distribute your version of this file under
32: * either the CDDL, the GPL Version 2 or to extend the choice of license to
33: * its licensees as provided above. However, if you add GPL Version 2 code
34: * and therefore, elected the GPL Version 2 license, then the option applies
35: * only if the new code is made subject to such option by the copyright
36: * holder.
37: */
38:
39: package javax.servlet.jsp.el;
40:
41: /**
42: * <p>The abstract class for a prepared expression.</p>
43: *
44: * <p>An instance of an Expression can be obtained via from an
45: * ExpressionEvaluator instance.</p>
46: *
47: * <p>An Expression may or not have done a syntactic parse of the expression.
48: * A client invoking the evaluate() method should be ready for the case
49: * where ELParseException exceptions are raised. </p>
50: *
51: * @deprecated As of JSP 2.1, replaced by {@link javax.el.ValueExpression}
52: * @since JSP 2.0
53: */
54: public abstract class Expression {
55:
56: /**
57: * Evaluates an expression that was previously prepared. In some
58: * implementations preparing an expression involves full syntactic
59: * validation, but others may not do so. Evaluating the expression may
60: * raise an ELParseException as well as other ELExceptions due to
61: * run-time evaluation.
62: *
63: * @param vResolver A VariableResolver instance that can be used at
64: * runtime to resolve the name of implicit objects into Objects.
65: * @return The result of the expression evaluation.
66: *
67: * @exception ELException Thrown if the expression evaluation failed.
68: */
69: public abstract Object evaluate(VariableResolver vResolver)
70: throws ELException;
71: }
|