/*
* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch 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.elasticsearch.hadoop.util;
import java.lang.reflect.AccessibleObject;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.Arrays;
import org.elasticsearch.hadoop.EsHadoopIllegalArgumentException;
import org.elasticsearch.hadoop.EsHadoopIllegalStateException;
public abstract class ReflectionUtils {
public static Field findField(Class<?> clazz, String name) {
return findField(clazz, name, null);
}
public static Field findField(Class<?> clazz, String name, Class<?> type) {
Assert.notNull(clazz, "Class must not be null");
Assert.isTrue(name != null || type != null, "Either name or type of the field must be specified");
Class<?> searchType = clazz;
while (!Object.class.equals(searchType) && searchType != null) {
Field[] fields = searchType.getDeclaredFields();
for (Field field : fields) {
if ((name == null || name.equals(field.getName())) && (type == null || type.equals(field.getType()))) {
return field;
}
}
searchType = searchType.getSuperclass();
}
return null;
}
@SuppressWarnings("unchecked")
public static <T> T getField(Field field, Object target) {
try {
return (T) field.get(target);
} catch (IllegalAccessException ex) {
throw new EsHadoopIllegalStateException("Unexpected reflection exception - " + ex.getClass().getName() + ": "+ ex.getMessage());
}
}
public static void setField(Field field, Object target, Object value) {
try {
field.set(target, value);
} catch (IllegalAccessException ex) {
throw new EsHadoopIllegalStateException("Unexpected reflection exception - " + ex.getClass().getName() + ": "+ ex.getMessage());
}
}
public static void makeAccessible(AccessibleObject accessible) {
if (!accessible.isAccessible()) {
accessible.setAccessible(true);
}
}
public static Method findMethod(Class<?> targetClass, String name, Class<?>... paramTypes) {
while (targetClass != null) {
Method[] methods = (targetClass.isInterface() ? targetClass.getMethods() : targetClass.getDeclaredMethods());
for (Method method : methods) {
if (name.equals(method.getName())
&& (paramTypes == null || Arrays.equals(paramTypes, method.getParameterTypes()))) {
return method;
}
}
targetClass = targetClass.getSuperclass();
}
return null;
}
@SuppressWarnings("unchecked")
public static <T> T invoke(Method method, Object target, Object...args) {
try {
return (T) method.invoke(target, args);
} catch (Exception ex) {
throw new EsHadoopIllegalArgumentException("Cannot invoke method " + method, ex);
}
}
}