001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018 package org.apache.commons.jexl2.internal;
019 import java.lang.reflect.InvocationTargetException;
020 /**
021 * Specialized executor to get a boolean property from an object.
022 * @since 2.0
023 */
024 public final class BooleanGetExecutor extends AbstractExecutor.Get {
025 /** The property. */
026 private final String property;
027 /**
028 * Creates an instance by attempting discovery of the get method.
029 * @param is the introspector
030 * @param clazz the class to introspect
031 * @param key the property to get
032 */
033 public BooleanGetExecutor(Introspector is, Class<?> clazz, String key) {
034 super(clazz, discover(is, clazz, key));
035 property = key;
036 }
037
038 /** {@inheritDoc} */
039 @Override
040 public Object getTargetProperty() {
041 return property;
042 }
043
044 /** {@inheritDoc} */
045 @Override
046 public Object execute(Object obj)
047 throws IllegalAccessException, InvocationTargetException {
048 return method == null ? null : method.invoke(obj, (Object[]) null);
049 }
050
051 /** {@inheritDoc} */
052 @Override
053 public Object tryExecute(Object obj, Object key) {
054 if (obj != null && method != null
055 // ensure method name matches the property name
056 && property.equals(key)
057 && objectClass.equals(obj.getClass())) {
058 try {
059 return method.invoke(obj, (Object[]) null);
060 } catch (InvocationTargetException xinvoke) {
061 return TRY_FAILED; // fail
062 } catch (IllegalAccessException xill) {
063 return TRY_FAILED;// fail
064 }
065 }
066 return TRY_FAILED;
067 }
068
069 /**
070 * Discovers the method for a {@link BooleanGet}.
071 * <p>The method to be found should be named "is{P,p}property and return a boolean.</p>
072 *@param is the introspector
073 *@param clazz the class to find the get method from
074 *@param property the the property name
075 *@return the method if found, null otherwise
076 */
077 static java.lang.reflect.Method discover(Introspector is, final Class<?> clazz, String property) {
078 java.lang.reflect.Method m = PropertyGetExecutor.discoverGet(is, "is", clazz, property);
079 return (m != null && m.getReturnType() == Boolean.TYPE) ? m : null;
080 }
081
082 }