com.carrotsearch.sizeof.Constants Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of java-sizeof Show documentation
Show all versions of java-sizeof Show documentation
Java Objects size estimation.
The newest version!
package com.carrotsearch.sizeof;
/**
* 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.
*/
import java.lang.reflect.Field;
/**
* Some useful constants.
**/
final class Constants {
private Constants() {} // can't construct
/** True iff running on a 64bit JVM */
public static final boolean JRE_IS_64BIT;
/** The value of System.getProperty("java.version"). **/
public static final String JAVA_VERSION = System.getProperty("java.version");
public static final String JAVA_VENDOR = System.getProperty("java.vendor");
public static final String JVM_VENDOR = System.getProperty("java.vm.vendor");
public static final String JVM_VERSION = System.getProperty("java.vm.version");
public static final String JVM_NAME = System.getProperty("java.vm.name");
public static final String OS_ARCH = System.getProperty("os.arch");
public static final String OS_VERSION = System.getProperty("os.version");
static {
final String OS_ARCH = System.getProperty("os.arch");
boolean is64Bit = false;
try {
final Class unsafeClass = Class.forName("sun.misc.Unsafe");
final Field unsafeField = unsafeClass.getDeclaredField("theUnsafe");
unsafeField.setAccessible(true);
final Object unsafe = unsafeField.get(null);
final int addressSize = ((Number) unsafeClass.getMethod("addressSize").invoke(unsafe)).intValue();
is64Bit = addressSize >= 8;
} catch (Exception e) {
final String x = System.getProperty("sun.arch.data.model");
if (x != null) {
is64Bit = x.indexOf("64") != -1;
} else {
if (OS_ARCH != null && OS_ARCH.indexOf("64") != -1) {
is64Bit = true;
} else {
is64Bit = false;
}
}
}
JRE_IS_64BIT = is64Bit;
}
}