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 service providers , where the service interface is JMXConnectorProvider
.
Every implementation must support the RMI connector protocol with the default RMI transport, specified with string rmi
.
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.