01: /*
02: * Copyright 2004,2004 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.bsf.util;
18:
19: import java.util.Hashtable;
20:
21: /**
22: * An <code>ScriptSymbolTable</code> object is used by a <code>CodeBuffer</code>
23: * object to implement nested scopes.
24: *
25: * @author Matthew J. Duftler
26: */
27: class ScriptSymbolTable extends Hashtable {
28: private Hashtable parentTable;
29:
30: ScriptSymbolTable(Hashtable parentTable) {
31: this .parentTable = parentTable;
32: }
33:
34: public synchronized Object get(Object key) {
35: Object ret = super.get(key);
36:
37: if (ret == null && parentTable != null)
38: ret = parentTable.get(key);
39:
40: return ret;
41: }
42: }
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