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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *      https://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  package org.apache.commons.jexl3.jexl342;
18  
19  import org.apache.commons.jexl3.JexlEngine;
20  import org.apache.commons.jexl3.JexlException;
21  import org.apache.commons.jexl3.introspection.JexlPropertySet;
22  
23  /**
24   * Wraps a reference or optional property set executor.
25   */
26  public class ReferenceSetExecutor implements JexlPropertySet {
27      /** The reference handler. */
28      private final ReferenceUberspect.ReferenceHandler handler;
29      /** The previous setter we did delegate to. */
30      private final JexlPropertySet setter;
31  
32      /**
33       * Creates an instance.
34       *
35       * @param referenceHandler the reference handler
36       * @param jexlSet the property setter
37       */
38      public ReferenceSetExecutor(final ReferenceUberspect.ReferenceHandler referenceHandler, final JexlPropertySet jexlSet) {
39          if (referenceHandler == null || jexlSet == null) {
40              throw new IllegalArgumentException("handler and setter cant be null");
41          }
42          this.handler = referenceHandler;
43          this.setter = jexlSet;
44      }
45  
46      /**
47       * Dereference an expected optional or reference.
48       *
49       * @param opt the reference
50       * @return the reference value, TRY_FAILED if null
51       */
52      protected Object getReference(final Object opt) {
53          return handler.callGet(opt);
54      }
55  
56      @Override
57      public Object invoke(final Object opt, final Object arg) throws Exception {
58          final Object obj = getReference(opt);
59          return setter.invoke(obj, arg);
60      }
61  
62      @Override
63      public boolean isCacheable() {
64          return setter.isCacheable();
65      }
66  
67      @Override
68      public boolean tryFailed(final Object rval) {
69          return setter.tryFailed(rval);
70      }
71  
72      @Override
73      public Object tryInvoke(final Object opt, final Object key, final Object arg) throws JexlException.TryFailed {
74          final Object obj = getReference(opt);
75          return obj == opt? JexlEngine.TRY_FAILED : obj == null ? null : setter.tryInvoke(key, obj, arg);
76      }
77  }