Factory to create JMX API connector clients.  There
 are no instances of this class.
 Connections are usually made using the connect method of this class.  More
 advanced applications can separate the creation of the connector
 client, using newJMXConnector and the establishment of the connection itself, using
 JMXConnector.connect(Map).
 Each client is created by an instance of JMXConnectorProvider.  This instance is found as follows.  Suppose
 the given JMXServiceURL looks like
 "service:jmx:protocol:remainder".
 Then the factory will attempt to find the appropriate JMXConnectorProvider for protocol.  Each
 occurrence of the character + or - in
 protocol is replaced by . or
 _, respectively.
 A provider package list is searched for as follows:
 
 - If the 
environment parameter to newJMXConnector contains the
 key jmx.remote.protocol.provider.pkgs then the
 associated value is the provider package list.
  - Otherwise, if the system property
 
jmx.remote.protocol.provider.pkgs exists, then its value
 is the provider package list.
  - Otherwise, there is no provider package list.
 
 
 The provider package list is a string that is interpreted as a
 list of non-empty Java package names separated by vertical bars
 (|).  If the string is empty, then so is the provider
 package list.  If the provider package list is not a String, or if
 it contains an element that is an empty string, a JMXProviderException is thrown.
 If the provider package list exists and is not empty, then for
 each element pkg of the list, the factory
 will attempt to load the class
 
 pkg.protocol.ClientProvider
 
 If the environment parameter to newJMXConnector contains the
 key jmx.remote.protocol.provider.class.loader then the
 associated value is the class loader to use to load the provider.
 If the associated value is not an instance of ClassLoader, an IllegalArgumentException is thrown.
 If the jmx.remote.protocol.provider.class.loader
 key is not present in the environment parameter, the
 calling thread's context class loader is used.
 If the attempt to load this class produces a ClassNotFoundException, the search for a handler continues with
 the next element of the list.
 Otherwise, a problem with the provider found is signalled by a
 JMXProviderException whose cause indicates the underlying
 exception, as follows:
 
 - if the attempt to load the class produces an exception other
 than 
ClassNotFoundException, that is the
 cause;
  - if 
Class.newInstance() for the class produces an
 exception, that is the cause.
  
 If no provider is found by the above steps, including the
 default case where there is no provider package list, then the
 implementation will use its own provider for
 protocol, or it will throw a
 MalformedURLException if there is none.  An
 implementation may choose to find providers by other means.  For
 example, it may support the 
 JAR conventions for service providers, where the service
 interface is JMXConnectorProvider.
 Every implementation must support the RMI connector protocols,
 specified with the string rmi or
 iiop.
 Once a provider is found, the result of the
 newJMXConnector method is the result of calling newJMXConnector
 on the provider.
 The Map parameter passed to the
 JMXConnectorProvider is a new read-only
 Map that contains all the entries that were in the
 environment parameter to JMXConnectorFactory.newJMXConnector, if there was one.
 Additionally, if the
 jmx.remote.protocol.provider.class.loader key is not
 present in the environment parameter, it is added to
 the new read-only Map.  The associated value is the
 calling thread's context class loader.