The Instance Namespace

WARNING

This namespace is now deprecated, simply because the same functionality can be achieved using the standard Coherence class-scheme and instance Cache Configuration elements.

The Instance Namespace is used to specify how instances of classes to be created on demand. It is typically used with in the context of other namespaces in order to specify customized implementations.

Namespace Content Handler

The implementation is provided by the com.oracle.coherence.environment.extensible.namespaces.InstanceNamespaceContentHandler class.

Declaration

The common prefix used for this namespace in Cache Configurations is instance, however as with all XML namespace declarations this can be defined arbitrarily when declaring the namespace.

To use the namespace you should declare it as follows:

<cache-config xmlns:instance="class://com.oracle.coherence.environment.extensible.namespaces.InstanceNamespaceContentHandler">

   ...

</cache-config>

Elements

The following element is defined by this Namespace.

<instance:class>

The instance:class element specifies how to create an instance of the specified class. The constructor is matched against the parameters specified as child elements.

Resolved Element Type:

When processed this element will be resolved to produce a ParameterizedBuilder<?>.

Attributes:

The following attributes are permitted in the instance:class element.

• classname (required attribute)

  A java.lang.String defining the name of the class to be instantiated.

Child Elements:

Child elements from the Instance Namespace and the Value Namespace are valid elements in this Namespace. These are used as constructor parameters for the class specified by the class-name attribute.

Examples:

A simple no argument constructor class:

<instance:class classname="MyClass"/>

A class taking two parameters:

<instance:class classname="java.awt.Point">
    <value:long>100</value:long>
    <value:long>100</value:long>
</instance:class>

A class with nested instances:

<instance:class classname="java.awt.Rectangle">
    <instance:class classname="java.awt.Point">
        <value:long>0</value:long>
        <value:long>0</value:long>
    </instance:class>
    <instance:class classname="java.awt.Point">
        <value:long>100</value:long>
        <value:long>100</value:long>
    </instance:class>
</instance:class>