Touring Language APIs - Beginning Java 7 - page 359

• float getFloat(Object object) returns the value of the floating-
point field for the specified object .
• int getInt(Object object) returns the value of the integer field for
the specified object .
• long getLong(Object object) returns the value of the long integer
field for the specified object .
• short getShort(Object object) returnsthevalueoftheshortinteger
field for the specified object .
get() returns the value of any type of field. In contrast, the other listed methods
returnthevaluesofspecifictypesoffields.Thesemethodsthrow NullPointerEx-
ception when object is null and the field is an instance field, IllegalAr-
gumentException when object is not an instance of the class or interface de-
claringtheunderlyingfield(ornotaninstanceofasubclassorinterfaceimplementor),
and IllegalAccessException when the underlying field cannot be accessed (it
is private, for example).
Listing 4-14 demonstrates Field 's getInt(Object) method along with its
void setInt(Object obj, int i) counterpart.
Listing 4-14. Reflectively getting and setting the values of instance and class fields
import java.lang.reflect.Field;
class X
{
public int i = 10;
public static final double PI = 3.14;
}
class FieldAccessDemo
{
public static void main(String[] args)
{
try
{
Class<?> clazz = Class.forName("X");
X x = (X) clazz.newInstance();
Field f = clazz.getField("i");