4.2.1.2 TabularDataSupport Class

The TabularDataSupport class defines a table structure with an arbitrary number of rows which can be indexed by any number of columns. Each row is a CompositeData object, and all rows must have the same composite data description. The columns of the table are headed by the names of the data items which make up the uniform CompositeData rows. The constructor and the methods for adding rows verify that all rows are described by equal CompositeData instances.

The index consists of a subset of the data items in the common composite data structure. This subset must be a key which uniquely identifies each row of the table. When the table is instantiated, or when a row is added, the methods of this class ensure that the index can uniquely identify all rows. Often the index will be a single column, for instance a column containing unique strings or integers.

Both the composite data description of all rows and the list of items which form the index are given by the table description returned by the getOpenType method. This method defined in the TabularData interface returns the TabularType object which describes the table (see 4.1.2 Type Descriptor Classes).

The access methods of the TabularData class take an array of objects representing a key value which indexes one row and returns the CompositeData instance which makes up the designated row. A row of the table can also be removed by providing its key value. All rows of the table can also be retrieved in an enumeration.