Configuration Validation

As mentioned earlier the configuration file syntax only describes plug-ins in general, but does not know anything about concrete implementations. Thus configuration parameters of plug-ins have to be verified programmatically. nevisDataPorter provides some validation infrastructure to free plug-ins from repetitive validation code.

A plug-in has to provide a description of its configuration parameters in a public static class member called DESC. The following classes must be used.

/**
* Plug-In Description
*/
Desc(
    Class<?> objectType,  // class of the object to create.
    PluginType pluginType,  // type of the object e.g. DATASOURCE
    Param[] parameters      // description of all parameters.
);

/**
* Description of a configuration parameters.
*/
public Param(
    String name,            // name of the configuration attribute
    boolean mandatory,      // is the configuration attribute mandatory
    Object defaultValue,    // default value for non mandatory
    Validator validator,    // validates the configuration value
    boolean deferred,       // is deferred evaluation allowed
    boolean sensitive       // if the value can be shown in the exception
);

The Validator is an interface. nevisDataPorter provides a bunch of different implementations. Nevertheless, a plugin can provide its own Validators if necessary.