This class represents a field of a
class. Instances of Field are obtained by calling
the getField( ) and related
methods of java.lang.Class.
Field implements the Member
interface, so once you have obtained a Field
object, you can use getName(
)
, getModifiers( ),
and getdeclaringClass( ) to determine the name,
modifiers, and class of the field. Additionally, getType(
) returns the type of the field.
The set( ) method
sets the value of the represented field for a specified object. (If
the represented field is static, no object need be
specified, of course.) If the field is of a
primitive type, its value can be specified using a wrapper object of
type Boolean, Integer, and so
on, or it can be set using the setBoolean( ),
setInt( ), and related methods. Similarly, the
get( ) method queries the value of the represented
field for a specified object and returns the field value as an
Object. Various other methods query the field
value and return it as various primitive types.
In Java 5.0, Field
implements AnnotatedElement to support reflection
on field annotations. The new
getGenericType(
) method supports reflection on the generic
type of fields, and isEnumConstant(
) supports
fields of enum types.
Figure 10-93. java.lang.reflect.Field
public final class
Field extends AccessibleObject implements Member {
// No Constructor
// Public Instance Methods
public Object
get (Object
obj )
throws IllegalArgumentException, IllegalAccessException;
public boolean
getBoolean (Object
obj )
throws IllegalArgumentException, IllegalAccessException;
public byte
getByte (Object
obj )
throws IllegalArgumentException, IllegalAccessException;
public char
getChar (Object
obj )
throws IllegalArgumentException, IllegalAccessException;
public double
getDouble (Object
obj )
throws IllegalArgumentException, IllegalAccessException;
public float
getFloat (Object
obj )
throws IllegalArgumentException, IllegalAccessException;
5.0 public Type
getGenericType ( );
public int
getInt (Object
obj )
throws IllegalArgumentException, IllegalAccessException;
public long
getLong (Object
obj )
throws IllegalArgumentException, IllegalAccessException;
public short
getShort (Object
obj )
throws IllegalArgumentException, IllegalAccessException;
public Class<?>
getType ( );
5.0 public boolean
isEnumConstant ( );
public void
set (Object
obj , Object
value )
throws IllegalArgumentException, IllegalAccessException;
public void
setBoolean (Object
obj , boolean
z )
throws IllegalArgumentException, IllegalAccessException;
public void
setByte (Object
obj , byte
b )
throws IllegalArgumentException, IllegalAccessException;
public void
setChar (Object
obj , char
c )
throws IllegalArgumentException, IllegalAccessException;
public void
setDouble (Object
obj , double
d )
throws IllegalArgumentException, IllegalAccessException;
public void
setFloat (Object
obj , float
f )
throws IllegalArgumentException, IllegalAccessException;
public void
setInt (Object
obj , int
i )
throws IllegalArgumentException, IllegalAccessException;
public void
setLong (Object
obj , long
l )
throws IllegalArgumentException, IllegalAccessException;
public void
setShort (Object
obj , short
s )
throws IllegalArgumentException, IllegalAccessException;
5.0 public String
toGenericString ( );
// Methods Implementing Member
public Class<?>
getDeclaringClass ( );
public int
getModifiers ( );
public String
getName ( );
5.0 public boolean
isSynthetic ( );
// Public Methods Overriding AccessibleObject
5.0 public <T extends java.lang.annotation.Annotation> T
getAnnotation
(Class<T>
annotationClass );
5.0 public java.lang.annotation.Annotation[ ]
getDeclaredAnnotations ( );
// Public Methods Overriding Object
public boolean
equals (Object
obj );
public int
hashCode ( );
public String
toString ( );
}