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.