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.lang.reflect.InvocationTargetException;
20
21 import org.apache.commons.jexl3.JexlException;
22
23 /**
24 * Specialized executor to get a boolean property from an object.
25 *
26 * @since 2.0
27 */
28 public final class BooleanGetExecutor extends AbstractExecutor.Get {
29
30 /**
31 * Discovers a BooleanGetExecutor.
32 * <p>The method to be found should be named "is{P,p}property and return a boolean.</p>
33 *
34 * @param is the introspector
35 * @param clazz the class to find the get method from
36 * @param property the property name
37 * @return the executor if found, null otherwise
38 */
39 public static BooleanGetExecutor discover(final Introspector is, final Class<?> clazz, final String property) {
40 if (property != null && !property.isEmpty()) {
41 final java.lang.reflect.Method m = PropertyGetExecutor.discoverGet(is, "is", clazz, property);
42 if (m != null && (m.getReturnType() == Boolean.TYPE || m.getReturnType() == Boolean.class)) {
43 return new BooleanGetExecutor(clazz, m, property);
44 }
45 }
46 return null;
47 }
48
49 /** The property. */
50 private final String property;
51
52 /**
53 * Creates an instance by attempting discovery of the get method.
54 *
55 * @param clazz the class to introspect
56 * @param method the method held by this executor
57 * @param key the property to get
58 */
59 private BooleanGetExecutor(final Class<?> clazz, final java.lang.reflect.Method method, final String key) {
60 super(clazz, method);
61 property = key;
62 }
63
64 @Override
65 public Object getTargetProperty() {
66 return property;
67 }
68
69 @Override
70 public Object invoke(final Object obj) throws IllegalAccessException, InvocationTargetException {
71 return method == null ? null : method.invoke(obj, (Object[]) null);
72 }
73
74 @Override
75 public Object tryInvoke(final Object obj, final Object key) {
76 if (obj != null && method != null
77 // ensure method name matches the property name
78 && property.equals(key)
79 && objectClass.equals(obj.getClass())) {
80 try {
81 return method.invoke(obj, (Object[]) null);
82 } catch (final IllegalAccessException xill) {
83 return TRY_FAILED; // fail
84 } catch (final InvocationTargetException xinvoke) {
85 throw JexlException.tryFailed(xinvoke); // throw
86 }
87 }
88 return TRY_FAILED;
89 }
90 }