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