com.qq.tars.common.util.BeanAccessor Maven / Gradle / Ivy
/**
* Tencent is pleased to support the open source community by making Tars available.
*
* Copyright (C) 2016 THL A29 Limited, a Tencent company. All rights reserved.
*
* Licensed under the BSD 3-Clause License (the "License"); you may not use this file except
* in compliance with the License. You may obtain a copy of the License at
*
* https://opensource.org/licenses/BSD-3-Clause
*
* 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.qq.tars.common.util;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.Map;
import sun.misc.Unsafe;
public class BeanAccessor {
private static Unsafe unsafe;
private static Map, Map> beaninfoMap;
private static Map, Map> beanFieldOffsetMap;
public static String SERIALVERSIONUID = "serialVersionUID";
public static String FINAL = "final";
public static String STATIC = "static";
public static Unsafe getUnsafeInstance() {
if (unsafe != null) {
return unsafe;
}
synchronized (BeanAccessor.class) {
if (unsafe == null) {
unsafe = getUnsafe();
}
}
return unsafe;
}
public static Unsafe getUnsafe() {
Unsafe value;
try {
Class clazz = Class.forName("sun.misc.Unsafe");
Field field = clazz.getDeclaredField("theUnsafe");
field.setAccessible(true);
value = (Unsafe) field.get(null);
} catch (Exception e) {
throw new RuntimeException("error to get theUnsafe", e);
}
return value;
}
public static Map getBeanFieldMap(Class clazz) {
if (clazz == null) {
return null;
}
if (beaninfoMap == null) {
synchronized (BeanAccessor.class) {
if (beaninfoMap == null) {
beaninfoMap = new HashMap, Map>();
}
}
}
if (beaninfoMap == null) {
return null;
}
Map fieldMap = beaninfoMap.get(clazz);
if (fieldMap == null) {
synchronized (clazz) {
if ((fieldMap = beaninfoMap.get(clazz)) == null) {
Field[] fields = clazz.getDeclaredFields();
fieldMap = new LinkedHashMap(fields.length);
for (Field field : fields) {
fieldMap.put(field.getName(), field);
}
beaninfoMap.put(clazz, fieldMap);
}
}
}
return fieldMap;
}
public static long getBeanFieldOffset(Class clazz, String fieldName) {
if (clazz == null || fieldName == null) {
return -1;
}
if (beanFieldOffsetMap == null) {
synchronized (BeanAccessor.class) {
if (beanFieldOffsetMap == null) {
beanFieldOffsetMap = new HashMap, Map>();
}
}
}
Map offsetMap = beanFieldOffsetMap.get(clazz);
if (offsetMap == null) {
synchronized (clazz) {
if ((offsetMap = beanFieldOffsetMap.get(clazz)) == null) {
Map fieldMap = getBeanFieldMap(clazz);
offsetMap = new HashMap(fieldMap.size());
for (String key : fieldMap.keySet()) {
Field field = fieldMap.get(key);
String modifiers = Modifier.toString(field.getModifiers());
if (field.getName().equals(SERIALVERSIONUID) || modifiers.contains(FINAL) || modifiers.contains(STATIC)) {
continue;
}
long offset = getUnsafeInstance().objectFieldOffset(field);
offsetMap.put(key, offset);
}
beanFieldOffsetMap.put(clazz, offsetMap);
}
}
}
Long result = offsetMap == null ? null : offsetMap.get(fieldName);
return result == null ? -1 : result.longValue();
}
public static Object getBeanValue(Object bean, String fieldName) {
if (bean == null || fieldName == null) {
return null;
}
Class clazz = bean.getClass();
Map fieldMap = getBeanFieldMap(clazz);
Field field = fieldMap.get(fieldName);
Unsafe unsafe = getUnsafeInstance();
if (unsafe == null) {
try {
if (!field.isAccessible()) {
field.setAccessible(true);
}
return field.get(bean);
} catch (Exception e) {
throw new RuntimeException(e);
}
}
long offset = getBeanFieldOffset(clazz, fieldName);
if (offset == -1) {
return null;
}
Class type = field.getType();
if (type == boolean.class) {
return unsafe.getBoolean(bean, offset);
} else if (type == byte.class) {
return unsafe.getByte(bean, offset);
} else if (type == short.class) {
return unsafe.getShort(bean, offset);
} else if (type == char.class) {
return unsafe.getChar(bean, offset);
} else if (type == int.class) {
return unsafe.getInt(bean, offset);
} else if (type == long.class) {
return unsafe.getLong(bean, offset);
} else if (type == float.class) {
return unsafe.getFloat(bean, offset);
} else if (type == double.class) {
return unsafe.getDouble(bean, offset);
}
return unsafe.getObject(bean, offset);
}
public static void setBeanValue(Object bean, String fieldName, Object data) {
if (bean == null || fieldName == null) {
return;
}
Class clazz = bean.getClass();
Map fieldMap = getBeanFieldMap(clazz);
Field field = fieldMap.get(fieldName);
Unsafe unsafe = getUnsafeInstance();
if (unsafe == null) {
try {
field.set(bean, data);
} catch (Exception e) {
throw new RuntimeException(e);
}
}
long offset = getBeanFieldOffset(clazz, fieldName);
if (offset == -1) {
return;
}
Class type = field.getType();
if (type == boolean.class) {
unsafe.putBoolean(bean, offset, ((Boolean) data).booleanValue());
} else if (type == byte.class) {
unsafe.putByte(bean, offset, ((Byte) data).byteValue());
} else if (type == short.class) {
unsafe.putShort(bean, offset, ((Short) data).shortValue());
} else if (type == char.class) {
unsafe.putChar(bean, offset, ((Character) data).charValue());
} else if (type == int.class) {
unsafe.putInt(bean, offset, ((Integer) data).intValue());
} else if (type == long.class) {
unsafe.putLong(bean, offset, ((Long) data).longValue());
} else if (type == float.class) {
unsafe.putFloat(bean, offset, ((Float) data).floatValue());
} else if (type == double.class) {
unsafe.putDouble(bean, offset, ((Double) data).doubleValue());
} else {
unsafe.putObject(bean, offset, data);
}
}
}
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