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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.dubbo.common.utils;
import java.lang.reflect.Field;
import static org.apache.dubbo.common.utils.ClassUtils.getAllInheritedTypes;
/**
* The utilities class for Java Reflection {@link Field}
*
* @since 2.7.6
*/
public interface FieldUtils {
/**
* Like the {@link Class#getDeclaredField(String)} method without throwing any {@link Exception}
*
* @param declaredClass the declared class
* @param fieldName the name of {@link Field}
* @return if field can't be found, return null
*/
static Field getDeclaredField(Class declaredClass, String fieldName) {
try {
Field[] fields = declaredClass.getDeclaredFields();
for (int i = 0; i < fields.length; i++) {
if (fields[i].getName().equals(fieldName)) {
return fields[i];
}
}
return null;
} catch (Exception exception) {
throw new RuntimeException(exception);
}
}
/**
* Find the {@link Field} by the name in the specified class and its inherited types
*
* @param declaredClass the declared class
* @param fieldName the name of {@link Field}
* @return if can't be found, return null
*/
static Field findField(Class declaredClass, String fieldName) {
Field field = getDeclaredField(declaredClass, fieldName);
if (field != null) {
return field;
}
for (Class superType : getAllInheritedTypes(declaredClass)) {
field = getDeclaredField(superType, fieldName);
if (field != null) {
break;
}
}
if (field == null) {
throw new IllegalStateException(String.format("cannot find field %s,field is null", fieldName));
}
return field;
}
/**
* Find the {@link Field} by the name in the specified class and its inherited types
*
* @param object the object whose field should be modified
* @param fieldName the name of {@link Field}
* @return if can't be found, return null
*/
static Field findField(Object object, String fieldName) {
return findField(object.getClass(), fieldName);
}
/**
* Get the value of the specified {@link Field}
*
* @param object the object whose field should be modified
* @param fieldName the name of {@link Field}
* @return the value of the specified {@link Field}
*/
static Object getFieldValue(Object object, String fieldName) {
return getFieldValue(object, findField(object, fieldName));
}
/**
* Get the value of the specified {@link Field}
*
* @param object the object whose field should be modified
* @param field {@link Field}
* @return the value of the specified {@link Field}
*/
static T getFieldValue(Object object, Field field) {
boolean accessible = field.isAccessible();
Object value = null;
try {
if (!accessible) {
field.setAccessible(true);
}
value = field.get(object);
} catch (IllegalAccessException ignored) {
} finally {
field.setAccessible(accessible);
}
return (T) value;
}
/**
* Set the value for the specified {@link Field}
*
* @param object the object whose field should be modified
* @param fieldName the name of {@link Field}
* @param value the value of field to be set
* @return the previous value of the specified {@link Field}
*/
static T setFieldValue(Object object, String fieldName, T value) {
return setFieldValue(object, findField(object, fieldName), value);
}
/**
* Set the value for the specified {@link Field}
*
* @param object the object whose field should be modified
* @param field {@link Field}
* @param value the value of field to be set
* @return the previous value of the specified {@link Field}
*/
static T setFieldValue(Object object, Field field, T value) {
boolean accessible = field.isAccessible();
Object previousValue = null;
try {
if (!accessible) {
field.setAccessible(true);
}
previousValue = field.get(object);
field.set(object, value);
} catch (IllegalAccessException ignored) {
} finally {
field.setAccessible(accessible);
}
return (T) previousValue;
}
}