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 * http://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
18 package org.apache.commons.jexl3.internal.introspection;
19 import java.util.Map;
20
21 /**
22 * Specialized executor to set a property in a Map.
23 * @since 2.0
24 */
25 public final class MapSetExecutor extends AbstractExecutor.Set {
26 /** The java.util.map.put method used as an active marker in MapSet. */
27 private static final java.lang.reflect.Method MAP_SET = initMarker(Map.class, "put", Object.class, Object.class);
28 /** The property. */
29 private final Object property;
30 /** The property value class. */
31 private final Class<?> valueClass;
32
33 /**
34 * Attempts to discover a MapSetExecutor.
35 *
36 * @param is the introspector
37 * @param clazz the class to find the set method from
38 * @param identifier the key to use as an argument to the get method
39 * @param value the value to use as argument in map.put(key,value)
40 * @return the executor if found, null otherwise
41 */
42 public static MapSetExecutor discover(final Introspector is,
43 final Class<?> clazz,
44 final Object identifier,
45 final Object value) {
46 // we still need to ensure permissions grant access to put(...)
47 if (Map.class.isAssignableFrom(clazz) && is.getMethod(clazz, "put", identifier, value) != null) {
48 return new MapSetExecutor(clazz, MAP_SET, identifier, value);
49 }
50 return null;
51 }
52
53 /**
54 * Creates an instance.
55 * @param clazz the class the set method applies to
56 * @param method the method called through this executor
57 * @param key the key to use as 1st argument to the set method
58 * @param value the value to use as 2nd argument to the set method
59 */
60 private MapSetExecutor(final Class<?> clazz, final java.lang.reflect.Method method, final Object key, final Object value) {
61 super(clazz, method);
62 property = key;
63 valueClass = classOf(value);
64 }
65
66 @Override
67 public Object getTargetProperty() {
68 return property;
69 }
70
71 @Override
72 public Object invoke(final Object obj, final Object value) {
73 @SuppressWarnings("unchecked") // ctor only allows Map instances - see discover() method
74 final Map<Object,Object> map = ((Map<Object, Object>) obj);
75 map.put(property, value);
76 return value;
77 }
78
79 @Override
80 public Object tryInvoke(final Object obj, final Object key, final Object value) {
81 if (obj != null
82 && method != null
83 && objectClass.equals(obj.getClass())
84 && ((property == null && key == null)
85 || (property != null && key != null && property.getClass().equals(key.getClass())))
86 && valueClass.equals(classOf(value))) {
87 @SuppressWarnings("unchecked") // ctor only allows Map instances - see discover() method
88 final Map<Object,Object> map = ((Map<Object, Object>) obj);
89 map.put(key, value);
90 return value;
91 }
92 return TRY_FAILED;
93 }
94 }