static String getSystemProperty(final String key, final String defaultValue) {
return getSecurityManager() == null ? getProperty(key, defaultValue) : doPrivileged(new ReadPropertyAction(key, defaultValue));
}
static String setSystemProperty(final String key, final String value) {
return getSecurityManager() == null ? setProperty(key, value) : doPrivileged(new WritePropertyAction(key, value));
}