org.apache.struts2.convention.ReflectionTools Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.struts2.convention;
import java.lang.annotation.Annotation;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;
/**
*
* This class has some reflection helpers.
*
*/
public class ReflectionTools {
/**
* Determines if the class given contains the method.
*
* @param clazz The class to check for the method.
* @param method The method name.
* @param parameterTypes The parameter types of the method.
* @return True if the method exists, false if not.
*/
public static boolean containsMethod(Class clazz, String method, Class... parameterTypes) {
try {
clazz.getMethod(method, parameterTypes);
return true;
} catch (NoSuchMethodException e) {
return false;
}
}
/**
* Retrieves the annotation from the given method in the given class.
*
* @param type of annotated class
* @param clazz The class.
* @param methodName The method.
* @param annotationClass The annotation to get.
* @return The annotation or null if it doesn't exist.
*/
public static T getAnnotation(Class clazz, String methodName, Class annotationClass) {
try {
Method method = clazz.getMethod(methodName);
return method.getAnnotation(annotationClass);
} catch (NoSuchMethodException e) {
throw new RuntimeException(e);
}
}
/**
* Return the list of parent classes in order (Object will be at index 0)
* @param clazz class to process
* @return hierarchy of classes
*/
public static List> getClassHierarchy(Class clazz) {
List> classes = new ArrayList<>();
while (clazz != null) {
classes.add(0, clazz);
clazz = clazz.getSuperclass();
}
return classes;
}
}