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EclipseLink build based upon Git transaction f2b9fc5
/*
* Copyright (c) 1998, 2018 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0 which is available at
* http://www.eclipse.org/legal/epl-2.0,
* or the Eclipse Distribution License v. 1.0 which is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
*/
// Contributors:
// Tomas Kraus, Peter Benedikovic - initial API and implementation
package org.eclipse.persistence.internal.helper;
import java.lang.reflect.Method;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.eclipse.persistence.internal.security.PrivilegedAccessHelper;
/**
* Java version storage class. Used for version numbers retrieved from
* Java specification version string. Stored version is in
* <major>.<minor> format.
* @author Tomas Kraus, Peter Benedikovic
*/
public final class JavaVersion {
/** JavaEE platform version elements separator character. */
public static final char SEPARATOR = '.';
/** JavaEE platform patch version element separator character. */
public static final char PATCH_SEPARATOR = '_';
/** Java VM version system property name. */
public static final String VM_VERSION_PROPERTY = "java.specification.version";
/**
* Compiled regular expression pattern to read individual version number components.
* Expected input is string like java version "1.6" or 9.
*/
private static final Pattern VM_VERSION_PATTERN = Pattern.compile(
"[^0-9]*([0-9]+)(\\.([0-9]+))*"
);
/** Number of Matcher groups (REGEX tokens) expected in Java VM
* version output. */
private static final int VM_MIN_VERSION_TOKENS = 1;
/**
* Retrieves Java specification version {@see String} from JDK system property.
* @return Java specification version {@see String} from JDK system property.
*/
public static String vmVersionString() {
return PrivilegedAccessHelper.getSystemProperty(VM_VERSION_PROPERTY);
}
// EclipseLink still supports JDK <9 so using Runtime.Version to retrieve
// current JDK version is optional and can only be done trough reflection calls.
// TODO: Remove reflection after JDK <9 support is dropped.
/** JDK 9+ java.lang.Runtime.Version class name. */
private static final String VERSION_CLASS_NAME = "java.lang.Runtime$Version";
/** JDK 9+ java.lang.Runtime static version() method name. */
private static final String RUNTIME_VERSION_METHOD_NAME = "version";
/**
* Invoke {@code Runtime#version()} method to retrieve {@code Runtime.Version} instance.
* @return {@code Runtime.Version} instance for JDK 9 and later or {@code null} otherwise.
*/
private static Object runtimeVersionObject() {
try {
final Method m = Runtime.class.getMethod(RUNTIME_VERSION_METHOD_NAME);
return m.invoke(null);
// Do not log, because AbstractSessionLog.getLog() causes cyclic dependency on ClassConstants during class initialization.
// NoSuchMethodException: JDK <9, can't use java.lang.Runtime.Version.
} catch (NoSuchMethodException e) {
return null;
// Other ReflectiveOperationException should not happen here. Otherwise throw it as RuntimeException.
} catch (ReflectiveOperationException e) {
throw new IllegalStateException(e);
}
}
/**
* Invoke {@code Runtime.Version} method with given name ({@code major} or {@code minor}) to retrieve version numbers.
* @param vClass {@code Runtime.Version} class.
* @param vObj {@code Runtime.Version} class instance containing JDK version information.
* @param name name of {@code Runtime.Version} instance method to invoke.
*/
private static Integer getRuntimeVersionNumber(final Object vObj, final String name) {
try {
final Method m = vObj.getClass().getMethod(name);
return (Integer) m.invoke(vObj);
// Do not log, because AbstractSessionLog.getLog() causes cyclic dependency on ClassConstants during class initialization.
// ReflectiveOperationException should not happen here. Otherwise throw it as RuntimeException.
} catch (ReflectiveOperationException e) {
throw new IllegalStateException(e);
}
}
/**
* Retrieve JDK version numbers from {@code Runtime.Version} instance returned by {@code Runtime#version()} method.
* This works only for JDK 9 and later.
* @return Current JDK version for JDK 9 and later or {@code null} otherwise or when any problem with version retrieval happened.
*/
private static JavaVersion runtimeVersion() {
final Object vObj = runtimeVersionObject();
if (vObj == null) {
return null;
}
final Integer major = getRuntimeVersionNumber(vObj, "major");
final Integer minor = getRuntimeVersionNumber(vObj, "minor");
if (major != null && minor != null) {
return new JavaVersion(major, minor);
}
return null;
}
/**
* Parse Java specification version from JDK system property provided as an argument.
* Version string should look like:
* "MA.MI"
*
* Where
* MA is major version number,
* MI is minor version number
*
* Label java version is parsed as non case sensitive.
* @return Current JDK version for any JDK from system property.
*/
private static JavaVersion propertyVersionParser(final String version) {
final Matcher matcher = VM_VERSION_PATTERN.matcher(version);
int major = 0, minor = 0;
if (matcher.find()) {
major = Integer.parseInt(matcher.group(1));
String min = matcher.group(VM_MIN_VERSION_TOKENS + 2);
minor = min != null ? Integer.parseInt(min) : 0;
}
return new JavaVersion(major, minor);
}
/**
* Retrieve Java specification version from JDK system property.
* @return Current JDK version for any JDK from system property.
*/
private static JavaVersion propertyVersion() {
return propertyVersionParser(vmVersionString());
}
/**
* Java specification version detector.
*/
public static JavaVersion vmVersion() {
final JavaVersion version = runtimeVersion();
return version != null ? version : propertyVersion();
}
/** Major version number. */
private final int major;
/** Minor version number. */
private final int minor;
/**
* Constructs an instance of Java specification version number.
* @param major Major version number.
* @param minor Minor version number.
*/
public JavaVersion(final int major, final int minor) {
this.major = major;
this.minor = minor;
}
/**
* Get major version number.
* @return Major version number.
*/
public final int getMajor() {
return major;
}
/**
* Get minor version number.
* @return Minor version number.
*/
public final int getMinor() {
return minor;
}
/**
* Compares this JavaVersion object against another one.
* @param version JavaVersion object to compare with
* this object.
* @return Compare result:
* Value 1 if this value
* is greater than supplied version value.
* Value -1 if this value
* is lesser than supplied version value.
* Value 0 if both this value
* and supplied version values are equal.
*
*/
public final int comapreTo(final JavaVersion version) {
return this.major > version.major ? 1 :
this.major < version.major ? -1 :
this.minor > version.minor ? 1 :
this.minor < version.minor ? -1 : 0;
}
/**
* Return String representation of Java VM version object.
* @return Java VM version string.
*/
@Override
public final String toString() {
final StringBuilder sb = new StringBuilder(3);
sb.append(major);
sb.append(SEPARATOR);
sb.append(minor);
return sb.toString();
}
/**
* Return {@link JavaSEPlatform} matching this Java SE specification version.
* @return {@link JavaSEPlatform} matching this Java SE specification version
* or {@code JavaSEPlatform.DEFAULT} as default when platform matching fails.
*/
public final JavaSEPlatform toPlatform() {
return JavaSEPlatform.toValue(major, minor);
}
}