Release 10.1A: OpenEdge Development:
Java Open Clients

Type interface

The Java SDO Type interface represents a common view of a data type. A Type has a Class object associated with it. For example, a Type representing a simple data type might have the java.lang.Integer class associated with it. A Type representing a complex data type might have a Customer class associated with it. Thus, java.lang.Class implements the Java SDO Type interface.

So, both a DataObject and a Property object has a Type associated with it. Typically, the Type of a DataObject is a complex data type like the Customer class, and the type of a Property is a simple data type like the java.lang.Integer class. A Type that represents a complex data type also has a Property list associated with it. So, for example, a Type representing the Customer class has a list of Property objects corresponding to the Customer columns or fields. A Type that corresponds to a simple data type defines no Property lists.

In the ProDataGraph model, a temp-table defined by a ProDataObjectMetaData object has a Type with a Property list that includes column properties, which map to the temp-table fields, and reference properties, which implement any data-relations specified by a ProDataRelationMetaData object. Each of the properties in this list also has a Type. So, both the DataObject (or ProDataObject for a ProDataGraph) and its list of Property objects have a getType() method that returns the Type of the respective object.

Methods

The Java SDO Type interface provides these methods:

getInstanceClass( ) and getClass( ) — These methods return the Java class that this Type represents. If this is the Type of a reference property, getInstanceClass() returns null:

Syntax

java.lang.Class getInstanceClass() java.lang.Class getClass()

getProperties( ) — This method returns the list of the properties for the Type of a DataObject. For a Type representing the simple data type of a Property (for example, java.lang.Integer), it returns null:

Syntax

java.util.List getProperties()

getProperty( ) — This method returns the property with the specified name from the property list of a DataObject Type. For a column property of a ProDataObject, propName is also the 4GL name of a corresponding temp-table field:

Syntax

Property getGetProperty(String propName)

isInstance( ) — This method returns whether the specified object is an instance of this Type. For example, if Type represents the Customer class and obj is a DataObject whose Type represents the Customer class, this method returns true:

Syntax

boolean isInstance(java.lang.Object obj)