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
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 *
24 * @since 2.0
25 */
26 public final class MapSetExecutor extends AbstractExecutor.Set {
27
28 /** The java.util.map.put method used as an active marker in MapSet. */
29 private static final java.lang.reflect.Method MAP_SET = initMarker(Map.class, "put", Object.class, Object.class);
30
31 /**
32 * Attempts to discover a MapSetExecutor.
33 *
34 * @param is the introspector
35 * @param clazz the class to find the set method from
36 * @param identifier the key to use as an argument to the get method
37 * @param value the value to use as argument in map.put(key, value)
38 * @return the executor if found, null otherwise
39 */
40 public static MapSetExecutor discover(final Introspector is,
41 final Class<?> clazz,
42 final Object identifier,
43 final Object value) {
44 // we still need to ensure permissions grant access to put(...)
45 if (Map.class.isAssignableFrom(clazz) && is.getMethod(clazz, "put", identifier, value) != null) {
46 return new MapSetExecutor(clazz, MAP_SET, identifier, value);
47 }
48 return null;
49 }
50
51 /** The property. */
52 private final Object property;
53
54 /** The property value class. */
55 private final Class<?> valueClass;
56
57 /**
58 * Creates an instance.
59 *
60 * @param clazz the class the set method applies to
61 * @param method the method called through this executor
62 * @param key the key to use as 1st argument to the set method
63 * @param value the value to use as 2nd argument to the set method
64 */
65 private MapSetExecutor(final Class<?> clazz, final java.lang.reflect.Method method, final Object key, final Object value) {
66 super(clazz, method);
67 property = key;
68 valueClass = classOf(value);
69 }
70
71 @Override
72 public Object getTargetProperty() {
73 return property;
74 }
75
76 @Override
77 public Object invoke(final Object obj, final Object value) {
78 @SuppressWarnings("unchecked") // ctor only allows Map instances - see discover() method
79 final Map<Object,Object> map = (Map<Object, Object>) obj;
80 map.put(property, value);
81 return value;
82 }
83
84 @Override
85 public Object tryInvoke(final Object obj, final Object key, final Object value) {
86 if (obj != null
87 && method != null
88 && objectClass.equals(obj.getClass())
89 && (property == null && key == null
90 || property != null && key != null && property.getClass().equals(key.getClass()))
91 && valueClass.equals(classOf(value))) {
92 @SuppressWarnings("unchecked") // ctor only allows Map instances - see discover() method
93 final Map<Object,Object> map = (Map<Object, Object>) obj;
94 map.put(key, value);
95 return value;
96 }
97 return TRY_FAILED;
98 }
99 }