com.baidu.bjf.remoting.protobuf.utils.FieldUtils Maven / Gradle / Ivy
/*
* Copyright (c) Baidu Inc. All rights reserved.
*
* 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 com.baidu.bjf.remoting.protobuf.utils;
import java.lang.annotation.Annotation;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.logging.Level;
import java.util.logging.Logger;
import com.baidu.bjf.remoting.protobuf.annotation.Protobuf;
/**
* Field utility class.
*
* @author xiemalin
* @since 1.0.0
*/
public final class FieldUtils {
private static final Map PRIMITIVE_TYPE_MAPPING;
static {
PRIMITIVE_TYPE_MAPPING = new HashMap();
PRIMITIVE_TYPE_MAPPING.put(int.class.getSimpleName(), Integer.class.getSimpleName());
PRIMITIVE_TYPE_MAPPING.put(long.class.getSimpleName(), Long.class.getSimpleName());
PRIMITIVE_TYPE_MAPPING.put(short.class.getSimpleName(), Short.class.getSimpleName());
PRIMITIVE_TYPE_MAPPING.put(boolean.class.getSimpleName(), Boolean.class.getSimpleName());
PRIMITIVE_TYPE_MAPPING.put(double.class.getSimpleName(), Double.class.getSimpleName());
PRIMITIVE_TYPE_MAPPING.put(float.class.getSimpleName(), Float.class.getSimpleName());
PRIMITIVE_TYPE_MAPPING.put(char.class.getSimpleName(), Character.class.getSimpleName());
PRIMITIVE_TYPE_MAPPING.put(byte.class.getSimpleName(), Byte.class.getSimpleName());
}
/**
* Logger for this class
*/
private static final Logger LOGGER = Logger.getLogger(FieldUtils.class.getName());
public static String toObjectType(String primitiveType) {
if (PRIMITIVE_TYPE_MAPPING.containsKey(primitiveType)) {
return PRIMITIVE_TYPE_MAPPING.get(primitiveType);
}
return ClassHelper.getInternalName(primitiveType);
}
/**
* Get the field represented by the supplied {@link Field field object} on
* the specified {@link Object target object}. In accordance with
* {@link Field#get(Object)} semantics, the returned value is automatically
* wrapped if the underlying field has a primitive type.
*
* Thrown exceptions are handled via a call to
*
* @param t
* the target object from which to get the field
* @param name
* the field to get
* @return the field's current value
*/
public static Object getField(Object t, String name) {
Field field = findField(t.getClass(), name);
if (field == null) {
return null;
}
field.setAccessible(true);
try {
return field.get(t);
} catch (Exception e) {
LOGGER.log(Level.FINE, e.getMessage(), e);
}
return null;
}
/**
* Set the field represented by the supplied {@link Field field object} on
* the specified {@link Object target object} to the specified
* value. In accordance with {@link Field#set(Object, Object)}
* semantics, the new value is automatically unwrapped if the underlying
* field has a primitive type.
*
* Thrown exceptions are handled via a call to
*
* @param t
* the target object on which to set the field
* @param name
* the field to set
* @param value
* the value to set; may be null
*/
public static void setField(Object t, String name, Object value) {
Field field = findField(t.getClass(), name);
if (field == null) {
return;
}
field.setAccessible(true);
try {
field.set(t, value);
} catch (Exception e) {
LOGGER.log(Level.FINE, e.getMessage(), e);
}
}
/**
* Attempt to find a {@link Field field} on the supplied {@link Class} with
* the supplied name. Searches all superclasses up to
* {@link Object}.
*
* @param clazz
* the class to introspect
* @param name
* the name of the field
* @return the corresponding Field object, or null if not found
*/
public static Field findField(Class clazz, String name) {
return findField(clazz, name, null);
}
/**
* Attempt to find a {@link Field field} on the supplied {@link Class} with
* the supplied name and/or {@link Class type}. Searches all
* superclasses up to {@link Object}.
*
* @param clazz
* the class to introspect
* @param name
* the name of the field (may be null if type is
* specified)
* @param type
* the type of the field (may be null if name is
* specified)
* @return the corresponding Field object, or null if not found
*/
public static Field findField(Class clazz, String name, Class type) {
if (clazz == null) {
throw new IllegalArgumentException("Class must not be null");
}
if (name == null && type == null) {
throw new IllegalArgumentException(
"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 (int i = 0; i < fields.length; i++) {
Field field = fields[i];
if ((name == null || name.equals(field.getName()))
&& (type == null || type.equals(field.getType()))) {
return field;
}
}
searchType = searchType.getSuperclass();
}
return null;
}
/**
* To find out matched {@link Field} marked as {@link Protobuf} annotation
*
* @param targetClass taget class
* @return found {@link Field} list
*/
public static List findMatchedFields(Class targetClass, Class ann) {
List ret = new ArrayList();
if (targetClass == null) {
return ret;
}
// Keep backing up the inheritance hierarchy.
do {
// Copy each field declared on this class unless it's static or
// file.
Field[] fields = targetClass.getDeclaredFields();
for (int i = 0; i < fields.length; i++) {
if (ann == null) {
ret.add(fields[i]);
continue;
}
Annotation protobuf = fields[i].getAnnotation(ann);
if (protobuf != null) {
ret.add(fields[i]);
}
}
targetClass = targetClass.getSuperclass();
} while (targetClass != null && targetClass != Object.class);
return ret;
}
}