/*
* Copyright (C) 2004, 2005, 2006 Joe Walnes.
* Copyright (C) 2006, 2007, 2008 XStream Committers.
* All rights reserved.
*
* The software in this package is published under the terms of the BSD
* style license a copy of which has been included with this distribution in
* the LICENSE.txt file.
*
* Created on 09. May 2004 by Joe Walnes
*/
package com.thoughtworks.xstream.core;
import com.thoughtworks.xstream.converters.reflection.PureJavaReflectionProvider;
import com.thoughtworks.xstream.converters.reflection.ReflectionProvider;
import java.lang.ref.WeakReference;
import java.lang.reflect.Field;
import java.security.AccessControlException;
import java.text.AttributedString;
import java.util.HashMap;
import java.util.Map;
public class JVM {
private ReflectionProvider reflectionProvider;
private transient Map loaderCache = new HashMap();
private final boolean supportsAWT = loadClass("java.awt.Color") != null;
private final boolean supportsSwing = loadClass("javax.swing.LookAndFeel") != null;
private final boolean supportsSQL = loadClass("java.sql.Date") != null;
private static final String vendor = System.getProperty("java.vm.vendor");
private static final float majorJavaVersion = getMajorJavaVersion();
private static final boolean reverseFieldOrder = isHarmony() || (isIBM() && !is15());
static final float DEFAULT_JAVA_VERSION = 0.9f;
/**
* Parses the java version system property to determine the major java version,
* i.e. 1.x
*
* @return A float of the form 1.x
*/
private static final float getMajorJavaVersion() {
try {
return Float.parseFloat(System.getProperty("java.specification.version"));
} catch ( NumberFormatException e ){
// Some JVMs may not conform to the x.y.z java.version format
return DEFAULT_JAVA_VERSION;
}
}
public static boolean is14() {
return majorJavaVersion >= 1.4f;
}
public static boolean is15() {
return majorJavaVersion >= 1.5f || (isAndroid() && is09());
}
public static boolean is16() {
return majorJavaVersion >= 1.6f;
}
public static boolean is09() {
return majorJavaVersion >= 0.9f;
}
private static boolean isAndroid() {
return vendor.indexOf("Android") != -1;
}
private static boolean isSun() {
return vendor.indexOf("Sun") != -1;
}
private static boolean isApple() {
return vendor.indexOf("Apple") != -1;
}
private static boolean isHPUX() {
return vendor.indexOf("Hewlett-Packard Company") != -1;
}
private static boolean isIBM() {
return vendor.indexOf("IBM") != -1;
}
private static boolean isBlackdown() {
return vendor.indexOf("Blackdown") != -1;
}
private static boolean isDiablo() {
return vendor.indexOf("FreeBSD Foundation") != -1;
}
private static boolean isHarmony() {
return vendor.indexOf("Apache Software Foundation") != -1;
}
/*
* Support for sun.misc.Unsafe and sun.reflect.ReflectionFactory is present
* in JRockit versions R25.1.0 and later, both 1.4.2 and 5.0 (and in future
* 6.0 builds).
*/
private static boolean isBEAWithUnsafeSupport() {
// This property should be "BEA Systems, Inc."
if (vendor.indexOf("BEA") != -1) {
/*
* Recent 1.4.2 and 5.0 versions of JRockit have a java.vm.version
* string starting with the "R" JVM version number, i.e.
* "R26.2.0-38-57237-1.5.0_06-20060209..."
*/
String vmVersion = System.getProperty("java.vm.version");
if (vmVersion.startsWith("R")) {
/*
* We *could* also check that it's R26 or later, but that is
* implicitly true
*/
return true;
}
/*
* For older JRockit versions we can check java.vm.info. JRockit
* 1.4.2 R24 -> "Native Threads, GC strategy: parallel" and JRockit
* 5.0 R25 -> "R25.2.0-28".
*/
String vmInfo = System.getProperty("java.vm.info");
if (vmInfo != null) {
// R25.1 or R25.2 supports Unsafe, other versions do not
return (vmInfo.startsWith("R25.1") || vmInfo
.startsWith("R25.2"));
}
}
// If non-BEA, or possibly some very old JRockit version
return false;
}
private static boolean isHitachi() {
return vendor.indexOf("Hitachi") != -1;
}
private static boolean isSAP() {
return vendor.indexOf("SAP AG") != -1;
}
public Class loadClass(String name) {
try {
WeakReference reference = (WeakReference) loaderCache.get(name);
if (reference != null) {
Class cached = (Class) reference.get();
if (cached != null) {
return cached;
}
}
Class clazz = Class.forName(name, false, getClass().getClassLoader());
loaderCache.put(name, new WeakReference(clazz));
return clazz;
} catch (ClassNotFoundException e) {
return null;
}
}
public synchronized ReflectionProvider bestReflectionProvider() {
if (reflectionProvider == null) {
try {
if ( canUseSun14ReflectionProvider() ) {
String cls = "com.thoughtworks.xstream.converters.reflection.Sun14ReflectionProvider";
reflectionProvider = (ReflectionProvider) loadClass(cls).newInstance();
} else if (canUseHarmonyReflectionProvider()) {
String cls = "com.thoughtworks.xstream.converters.reflection.HarmonyReflectionProvider";
reflectionProvider = (ReflectionProvider) loadClass(cls).newInstance();
}
if (reflectionProvider == null) {
reflectionProvider = new PureJavaReflectionProvider();
}
} catch (InstantiationException e) {
reflectionProvider = new PureJavaReflectionProvider();
} catch (IllegalAccessException e) {
reflectionProvider = new PureJavaReflectionProvider();
} catch (AccessControlException e) {
// thrown when trying to access sun.misc package in Applet context.
reflectionProvider = new PureJavaReflectionProvider();
}
}
return reflectionProvider;
}
private boolean canUseSun14ReflectionProvider() {
return (isSun()
|| isApple()
|| isHPUX()
|| isIBM()
|| isBlackdown()
|| isBEAWithUnsafeSupport()
|| isHitachi()
|| isSAP()
|| isDiablo())
&& is14()
&& loadClass("sun.misc.Unsafe") != null;
}
private boolean canUseHarmonyReflectionProvider() {
return isHarmony();
}
public static boolean reverseFieldDefinition() {
return reverseFieldOrder;
}
/**
* Checks if the jvm supports awt.
*/
public boolean supportsAWT() {
return this.supportsAWT;
}
/**
* Checks if the jvm supports swing.
*/
public boolean supportsSwing() {
return this.supportsSwing;
}
/**
* Checks if the jvm supports sql.
*/
public boolean supportsSQL() {
return this.supportsSQL;
}
private Object readResolve() {
loaderCache = new HashMap();
return this;
}
public static void main(String[] args) {
boolean reverse = false;
Field[] fields = AttributedString.class.getDeclaredFields();
for (int i = 0; i < fields.length; i++) {
if (fields[i].getName().equals("text")) {
reverse = i > 3;
break;
}
}
if (reverse) {
fields = JVM.class.getDeclaredFields();
for (int i = 0; i < fields.length; i++) {
if (fields[i].getName().equals("reflectionProvider")) {
reverse = i > 2;
break;
}
}
}
JVM jvm = new JVM();
System.out.println("XStream JVM diagnostics");
System.out.println("java.specification.version: " + System.getProperty("java.specification.version"));
System.out.println("java.vm.vendor: " + vendor);
System.out.println("Version: " + majorJavaVersion);
System.out.println("XStream support for enhanced Mode: " + (jvm.canUseSun14ReflectionProvider() || jvm.canUseHarmonyReflectionProvider()));
System.out.println("Supports AWT: " + jvm.supportsAWT());
System.out.println("Supports Swing: " + jvm.supportsSwing());
System.out.println("Supports SQL: " + jvm.supportsSQL());
System.out.println("Reverse field order detected (may have failed): " + reverse);
}
}