ArcGIS Engine Developer Guide

JAVA APPLICATION PROGRAMMING INTERFACE
ArcObjects Struct
enum esri3DAxis
esriXAxis = 0
esriYAxis = 1
esriZAxis = 2
}
Java Representation
public interface esri3DAxis {
public static final int esriXAxis = 0;
public static final int esriYAxis = 1;
public static final int esriZAxis = 2;
}
You can now refer to the esriXAxis constant using the following notation:
esri3DAxis.esriXAxis;
Variants
The variant data type can contain a wide array of subtypes. With variants all
types can be contained within a single type variant. Everything in the Java programming
language is an object. Even primitive data types can be encapsulated
inside objects if required. Every class in Java extends java.lang.Object; consequently,
methods in ArcObjects that take variants as parameters can be passed any
object type in the ArcGIS API for Java.
Calling methods with “variant” objects as parameters
For methods that take variants as parameters, any object types can be passed, as
all objects derive from java.lang.Object. As this is considered a “widening cast,” an
explicit cast to Object is not needed. If you want to pass primitives as parameters
to methods, when variants are required, the corresponding primitive wrapper
class can be used.
Using methods that return variants
When using variant objects returned by methods, explicitly “downcast” those
objects to the corresponding wrapper object. For example, if expecting a String,
downcast to java.lang.String; if expecting a short, downcast to short’s wrapper
class, that is, java.lang.Short, as shown in the code below.
ICursor spCursor = spTable.ITable_search(spQueryFilter, false);
/* Iterate over the rows. */
IRow spRow = spCursor.nextRow();
while (spRow != null) {
Short ID = (Short) (spRow.getValue(1));
String name = (String) (spRow.getValue(2));
Short baseID = (Short) (spRow.getValue(3));
188 • ArcGIS Engine Developer Guide
System.out.println("ID="+ ID +"\t name="+ name +"\tbaseID="+ baseID);
/* Move to the next row. */
spRow = spCursor.nextRow();
}
IRowBuffer is a superinterface of IRow and defines the getValue(int) method as:
public Object getValue(int index)
throws IOException,
AutomationException
The value of the field with the specified index.
Parameters:
index - The index (in)
Returns:
return value. A Variant