Data Accessors

Immediate Access

Proxy interfaces and immediate-access data structure classes define methods that access data within component processes. These methods access data immediately (though indirectly):

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Methods that get data from the component always fetch new data with each call (they do not return stored data from earlier calls).

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Methods that set values in the component immediately store the new values (they do not hold values while waiting for another call). If the component rejects a value, the method throws an exception.

This immediate-access paradigm ensures that configuration programs and daemon components always remain synchronized throughout their interactions.

Program Credentials

Note

An important exception to this rule is SecurityProxy.useCredentials(), which is not a data access method. Instead, this method records an administrator name and password within the program (not within the daemon). A private method of SecurityProxy automatically supplies these credentials whenever the daemon requests them. For details see, SecurityProxy.useCredentials().

Read-Only Objects

Each proxy interface defines a method that gets general information from the component. These methods return an instance of a subclass of ComponentInformation. All of these instances are read-only:

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Methods that get data from these objects do not interact with the component.

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Programs cannot construct these objects; they exist only because getComponentInformation() methods return them.

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Programs cannot modify these objects.