cn.hutool.core.util.JdkUtil Maven / Gradle / Ivy
/*
* Copyright (c) 2023 looly([email protected])
* Hutool is licensed under Mulan PSL v2.
* You can use this software according to the terms and conditions of the Mulan PSL v2.
* You may obtain a copy of Mulan PSL v2 at:
* http://license.coscl.org.cn/MulanPSL2
* THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
* EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
* MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
* See the Mulan PSL v2 for more details.
*/
package cn.hutool.core.util;
/**
* JDK相关工具类，包括判断JDK版本等
* 工具部分方法来自fastjson2的JDKUtils
*
* @author fastjson, looly
*/
public class JdkUtil {
/**
* JDK版本
*/
public static final int JVM_VERSION;
/**
* 是否JDK8
* 由于Hutool基于JDK8编译，当使用JDK版本低于8时，不支持。
*/
public static final boolean IS_JDK8;
/**
* 是否大于等于JDK17
*/
public static final boolean IS_AT_LEAST_JDK17;
/**
* 是否Android环境
*/
public static final boolean IS_ANDROID;
static {
// JVM版本
JVM_VERSION = _getJvmVersion();
IS_JDK8 = 8 == JVM_VERSION;
IS_AT_LEAST_JDK17 = JVM_VERSION >= 17;
// JVM名称
final String jvmName = _getJvmName();
IS_ANDROID = jvmName.equals("Dalvik");
}
/**
* 获取JVM名称
*
* @return JVM名称
*/
private static String _getJvmName() {
return System.getProperty("java.vm.name");
}
/**
* 根据{@code java.specification.version}属性值，获取版本号
*
* @return 版本号
*/
private static int _getJvmVersion() {
int jvmVersion = -1;
try{
String javaSpecVer = System.getProperty("java.specification.version");
if (StrUtil.isNotBlank(javaSpecVer)) {
if (javaSpecVer.startsWith("1.")) {
javaSpecVer = javaSpecVer.substring(2);
}
if (javaSpecVer.indexOf('.') == -1) {
jvmVersion = Integer.parseInt(javaSpecVer);
}
}
} catch (Throwable ignore){
// 默认JDK8
jvmVersion = 8;
}
return jvmVersion;
}
}