Class JMXConnectorFactory

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:

1. If the environment parameter to newJMXConnector contains the key jmx.remote.protocol.provider.pkgs then the associated value is the provider package list.
2. Otherwise, if the system property jmx.remote.protocol.provider.pkgs exists, then its value is the provider package list.
3. 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 protocol with the default RMI transport, specified with string rmi. An implementation may optionally support the RMI connector protocol with the RMI/IIOP transport, specified with the string 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.

Fields

DEFAULT_CLASS_LOADER

public static final String DEFAULT_CLASS_LOADER

See Also:

Constant Field Values

PROTOCOL_PROVIDER_PACKAGES

public static final String PROTOCOL_PROVIDER_PACKAGES

See Also:

Constant Field Values

PROTOCOL_PROVIDER_CLASS_LOADER

public static final String PROTOCOL_PROVIDER_CLASS_LOADER

See Also:

Constant Field Values

Methods

connect

public static JMXConnector connect(JMXServiceURL serviceURL)
                            throws IOException

Parameters:

serviceURL - the address of the connector server to connect to.

Returns:

a JMXConnector whose connect method has been called.

Throws:

NullPointerException - if serviceURL is null.

IOException - if the connector client or the connection cannot be made because of a communication problem.

SecurityException - if the connection cannot be made for security reasons.

connect

public static JMXConnector connect(JMXServiceURL serviceURL,
                                   Map<String,?> environment)
                            throws IOException

JMXConnector conn = JMXConnectorFactory.newJMXConnector(serviceURL,
                                                         environment);
 conn.connect(environment);

Parameters:

serviceURL - the address of the connector server to connect to.

environment - a set of attributes to determine how the connection is made. This parameter can be null. Keys in this map must be Strings. The appropriate type of each associated value depends on the attribute. The contents of environment are not changed by this call.

Returns:

a JMXConnector representing the newly-made connection. Each successful call to this method produces a different object.

Throws:

NullPointerException - if serviceURL is null.

IOException - if the connector client or the connection cannot be made because of a communication problem.

SecurityException - if the connection cannot be made for security reasons.

newJMXConnector

public static JMXConnector newJMXConnector(JMXServiceURL serviceURL,
                                           Map<String,?> environment)
                                    throws IOException

Parameters:

serviceURL - the address of the connector server to connect to.

environment - a set of attributes to determine how the connection is made. This parameter can be null. Keys in this map must be Strings. The appropriate type of each associated value depends on the attribute. The contents of environment are not changed by this call.

Returns:

a JMXConnector representing the new connector client. Each successful call to this method produces a different object.

Throws:

NullPointerException - if serviceURL is null.

IOException - if the connector client cannot be made because of a communication problem.

MalformedURLException - if there is no provider for the protocol in serviceURL.

JMXProviderException - if there is a provider for the protocol in serviceURL but it cannot be used for some reason.