org.apache.cassandra.utils.JavaUtils Maven / Gradle / Ivy
/*
* 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.cassandra.utils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Utility method to retrieve information about the JRE.
*/
public final class JavaUtils
{
private static final Logger logger = LoggerFactory.getLogger(JavaUtils.class);
/**
* Checks if the specified JRE support ExitOnOutOfMemory and CrashOnOutOfMemory.
* @param jreVersion the JRE version
* @return {@code true} if the running JRE support ExitOnOutOfMemory and CrashOnOutOfMemory or if the exact version
* cannot be determined, {@code false} otherwise.
*/
public static boolean supportExitOnOutOfMemory(String jreVersion)
{
try
{
int version = parseJavaVersion(jreVersion);
if (version > 8)
return true;
int update = parseUpdateForPre9Versions(jreVersion);
// The ExitOnOutOfMemory and CrashOnOutOfMemory are supported since the version 7u101 and 8u92
return (version == 7 && update >= 101) || (version == 8 && update >= 92);
}
catch (Exception e)
{
logger.error("Some JRE information could not be retrieved for the JRE version: " + jreVersion, e);
// We will continue assuming that the version supports ExitOnOutOfMemory and CrashOnOutOfMemory.
return true;
}
}
/**
* Parses an Oracle JRE Version to extract the java version number.
* The parsing rules are based on the following
* String Naming Convention and
* JEP 223: New Version-String Scheme.
* @param jreVersion the Oracle JRE Version
* @return the java version number
* @throws NumberFormatException if the version cannot be retrieved
*/
private static int parseJavaVersion(String jreVersion)
{
String version;
if (jreVersion.startsWith("1."))
{
version = jreVersion.substring(2, 3); // Pre 9 version
}
else
{
// Version > = 9
int index = jreVersion.indexOf('.');
if (index < 0)
{
// Does not have a minor version so we need to check for EA release
index = jreVersion.indexOf('-');
if (index < 0)
index = jreVersion.length();
}
version = jreVersion.substring(0, index);
}
return Integer.parseInt(version);
}
/**
* Parses an Oracle JRE Version < 9 to extract the update version.
* The parsing rules are based on the following
* String Naming Convention.
* @param jreVersion the Oracle JRE Version
* @return the update version
* @throws NumberFormatException if the update cannot be retrieved
*/
private static int parseUpdateForPre9Versions(String jreVersion)
{
// Handle non GA versions
int dashSeparatorIndex = jreVersion.indexOf('-');
if (dashSeparatorIndex > 0)
jreVersion = jreVersion.substring(0, dashSeparatorIndex);
int updateSeparatorIndex = jreVersion.indexOf('_');
if (updateSeparatorIndex < 0)
return 0; // Initial release
return Integer.parseInt(jreVersion.substring(updateSeparatorIndex + 1));
}
private JavaUtils()
{
}
}