public class Test {

    public void test(){

        TimeZone.getDefault();

    }

}

    private static synchronized TimeZone setDefaultZone() {

        TimeZone tz;

        // get the time zone ID from the system properties

        String zoneID = AccessController.doPrivileged(

                new GetPropertyAction("user.timezone"));

        // if the time zone ID is not set (yet), perform the

        // platform to Java time zone ID mapping.

        if (zoneID == null || zoneID.isEmpty()) {

            String javaHome = AccessController.doPrivileged(

                    new GetPropertyAction("java.home"));

            try {

                zoneID = getSystemTimeZoneID(javaHome);

                if (zoneID == null) {

                    zoneID = GMT_ID;

                }

            } catch (NullPointerException e) {

                zoneID = GMT_ID;

            }

        }

        // Get the time zone for zoneID. But not fall back to

        // "GMT" here.

        tz = getTimeZone(zoneID, false);

        if (tz == null) {

            // If the given zone ID is unknown in Java, try to

            // get the GMT-offset-based time zone ID,

            // a.k.a. custom time zone ID (e.g., "GMT-08:00").

            String gmtOffsetID = getSystemGMTOffsetID();

            if (gmtOffsetID != null) {

                zoneID = gmtOffsetID;

            }

            tz = getTimeZone(zoneID, true);

        }

        assert tz != null;

        final String id = zoneID;

        AccessController.doPrivileged(new PrivilegedAction<Void>() {

            @Override

                public Void run() {

                    System.setProperty("user.timezone", id);

                    return null;

                }

            });

        defaultTimeZone = tz;

        return tz;

    }

JNIEXPORT jstring JNICALL

Java_java_util_TimeZone_getSystemTimeZoneID(JNIEnv *env, jclass ign,

                                            jstring java_home)

{

    const char *java_home_dir;

    char *javaTZ;

    jstring jstrJavaTZ = NULL;

    CHECK_NULL_RETURN(java_home, NULL);

    java_home_dir = JNU_GetStringPlatformChars(env, java_home, 0);

    CHECK_NULL_RETURN(java_home_dir, NULL);

    /*

     * Invoke platform dependent mapping function

     */

    javaTZ = findJavaTZ_md(java_home_dir);

    if (javaTZ != NULL) {

        jstrJavaTZ = JNU_NewStringPlatform(env, javaTZ);

        free((void *)javaTZ);

    }

    JNU_ReleaseStringPlatformChars(env, java_home, java_home_dir);

    return jstrJavaTZ;

}

char *

findJavaTZ_md(const char *java_home_dir)

{

    char *tz;

    char *javatz = NULL;

    char *freetz = NULL;

    tz = getenv("TZ");

#if defined(__linux__) || defined(_ALLBSD_SOURCE)

    if (tz == NULL) {

#else

#if defined (__solaris__) || defined(_AIX)

    if (tz == NULL || *tz == '\0') {

#endif

#endif

        tz = getPlatformTimeZoneID();

        freetz = tz;

    }

    /*

     * Remove any preceding ':'

     */

    if (tz != NULL && *tz == ':') {

        tz++;

    }

#ifdef __solaris__

    if (tz != NULL && strcmp(tz, "localtime") == 0) {

        tz = getSolarisDefaultZoneID();

        freetz = tz;

    }

#endif

    if (tz != NULL) {

#ifdef __linux__

        /*

         * Ignore "posix/" prefix.

         */

        if (strncmp(tz, "posix/", 6) == 0) {

            tz += 6;

        }

#endif

        javatz = strdup(tz);

        if (freetz != NULL) {

            free((void *) freetz);

        }

#ifdef _AIX

        freetz = mapPlatformToJavaTimezone(java_home_dir, javatz);

        if (javatz != NULL) {

            free((void *) javatz);

        }

        javatz = freetz;

#endif

    }

    return javatz;

}