Release 10.1A: OpenEdge Development:
Java Open Clients

Property interface

A Java SDO Property is contained in a property list associated with a DataObject, where each property in the list has a well defined index. In the ProDataGraph model, a Property corresponds to either a temp-table field (as a column property) or references another DataObject (as a reference property). A column property has a Type that is either a primitive type, such as int, or a commonly used class, such as java.lang.String. A reference property has a Type that refers to the Type of another DataObject. For example, the reference property of a DataObject of data type Customer might refer to one or more DataObject instances of data type Order.

A column property can be single-valued or many-valued. If a Progress 4GL temp-table field is defined with an extent option, its corresponding column property is defined as many-valued.

In the ProDataGraph model, a reference property is used to implement a data-relation defined by an associated ProDataRelationMetaData object. When you invoke the ProDataGraph setChildReferences() method, a reference property is added to each DataObject of every parent table that references a child table DataObject. A reference property is defined as many-valued so multiple child DataObject instances of the same type can be referenced in a given child table.

Methods

The Java SDO Property interface provides these methods:

getName( ) — This method returns the name of the Property. For a column property, this is the 4GL name of the corresponding temp-table field:

Syntax

String getName()

getType( ) — This method returns the Type of the Property:

Syntax

Type getType()

isMany( ) — This method returns true if this Property is defined as many-valued, and false if single-valued. If it returns true for a column property, the DataObject get*() methods return a java.lang.List. It always returns true for a reference property:

Syntax

boolean isMany()

getDefault( ) — This method returns the default value this Property has in a DataObject (as specified by Java SDO) when the property has not yet been set:

Syntax

Object getDefault()