The AccessParameter class and the classes derived from it define all parameters required to access record-oriented files (and which are supported) and contain at least the access method used and the associated file system, plus the default parameters record format and record length.
The access-method-specific implementations of this class can define additional parameters and then offer methods for setting and inquiring the values of these parameters. The subsections below describe the general methods which every implementation must provide, as well as the specific methods for the access methods currently supported.
Objects of the access-method-specific implementations of the AccessParameter class can be used to create new files in the corresponding file system using the relevant access method. Internally such objects are also used for other accesses to files (for example to open files). They can only be used to generate files in the file system from which they originate.
Objects of this abstract class cannot be generated by the user. However, the recordFile class provides the getAccessParameter() and getDefaultAccessParameter() methods which you can use to have objects of the access-method-specific implementations of this class returned.
Inadmissible values in the individual parameters are generally not discovered when the values are entered in the Parameter object, but only when this object is used.