01: /*
02: * Copyright 2002-2006 The Apache Software Foundation.
03: *
04: * Licensed under the Apache License, Version 2.0 (the "License");
05: * you may not use this file except in compliance with the License.
06: * You may obtain a copy of the License at
07: *
08: * http://www.apache.org/licenses/LICENSE-2.0
09: *
10: * Unless required by applicable law or agreed to in writing, software
11: * distributed under the License is distributed on an "AS IS" BASIS,
12: * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13: * See the License for the specific language governing permissions and
14: * limitations under the License.
15: */
16:
17: package org.apache.commons.jexl.parser;
18:
19: import org.apache.commons.jexl.JexlContext;
20:
21: /**
22: * Simple identifier - $foo or $foo.bar (both parts are identifiers).
23: *
24: * @author <a href="mailto:geirm@apache.org">Geir Magnusson Jr.</a>
25: * @version $Id: ASTIdentifier.java 398199 2006-04-29 16:30:05Z dion $
26: */
27: public class ASTIdentifier extends SimpleNode {
28: /** the name of the variable. */
29: protected String val;
30:
31: /**
32: * Create the node given an id.
33: *
34: * @param id node id.
35: */
36: public ASTIdentifier(int id) {
37: super (id);
38: }
39:
40: /**
41: * Create a node with the given parser and id.
42: *
43: * @param p a parser.
44: * @param id node id.
45: */
46: public ASTIdentifier(Parser p, int id) {
47: super (p, id);
48: }
49:
50: /** {@inheritDoc} */
51: public Object jjtAccept(ParserVisitor visitor, Object data) {
52: return visitor.visit(this , data);
53: }
54:
55: /** {@inheritDoc} */
56: public Object value(JexlContext jc) throws Exception {
57: return jc.getVars().get(val);
58: }
59:
60: /**
61: * returns the value of itself applied to the object. We assume that an
62: * identifier can be gotten via a get(String).
63: * e.g. if we have bean.property, 'property' has been parsed as an identifier,
64: * and we need to resolve the expression by calling the property getter.
65: *
66: * @param obj the object to evaluate against.
67: * @param jc the {@link JexlContext}.
68: * @throws Exception on any error.
69: * @return the resulting value.
70: * @see ASTArrayAccess#evaluateExpr(Object, Object)
71: */
72: public Object execute(Object obj, JexlContext jc) throws Exception {
73: return ASTArrayAccess.evaluateExpr(obj, val);
74: }
75:
76: /**
77: * Gets the name of the variable.
78: * @return the variable name.
79: */
80: public String getIdentifierString() {
81: return val;
82: }
83: }
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