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