java.lang.reflect
Class Field

java.lang.Object
  java.lang.reflect.AccessibleObject
      java.lang.reflect.Field

All Implemented Interfaces:

AnnotatedElement, Member

public final class Field
extends AccessibleObject
implements AnnotatedElement, Member

Field enables reflection access to Java fields.

Field Summary

Fields inherited from interface java.lang.reflect.Member

DECLARED, PUBLIC

Method Summary

boolean	equals(Object obj) equals checks if this field is equal to another field.
Object	get(Object obj) get returns the value of this field.
<T extends Annotation> T	getAnnotation(Class<T> annotationType) getAnnotation NYI: COMMENT: JDK 1.5 method description
boolean	getBoolean(Object obj) getBoolean returns the value of this boolean field.
byte	getByte(Object obj) getByte returns the value of this byte field.
char	getChar(Object obj) getChar returns the value of this char field.
Annotation[]	getDeclaredAnnotations() getDeclaredAnnotations NYI: COMMENT: JDK 1.5 method description
Class<?>	getDeclaringClass() getDeclaringClass returns the class this field was declared in.
double	getDouble(Object obj) getDouble returns the value of this doublue field.
float	getFloat(Object obj) getFloat returns the value of this float field.
Type	getGenericType() getGenericType NYI: COMMENT: JDK 1.5 method description
int	getInt(Object obj) getInt returns the value of this int field.
long	getLong(Object obj) getLong returns the value of this long field.
int	getModifiers() getModifiers returns the set of modifiers set for this field.
String	getName() getName returns the name of this field.
short	getShort(Object obj) getShort returns the value of this short field.
Class<?>	getType() getType returns the type of this field.
int	hashCode() hashCode returns a hash code for this field
boolean	isEnumConstant() isEnumConstant NYI: COMMENT: JDK 1.5 method description
boolean	isSynthetic() isSynthetic NYI: COMMENT: JDK 1.5 method description
void	set(Object o, Object v) set sets the value of this field.
void	setBoolean(Object obj, boolean z) setBoolean sets the value of this field.
void	setByte(Object obj, byte b) setByte sets the value of this field.
void	setChar(Object obj, char c) setChar sets the value of this field.
void	setDouble(Object obj, double d) setDouble sets the value of this field.
void	setFloat(Object obj, float f) setFloat sets the value of this field.
void	setInt(Object obj, int i) setInt sets the value of this field.
void	setLong(Object obj, long l) setLong sets the value of this field.
void	setShort(Object obj, short s) setShort sets the value of this field.
String	toGenericString() toGenericString NYI: COMMENT: JDK 1.5 method description
String	toString() toString converts this field to a string such as "public java.io.PrintStream java.lang.System.out".

Methods inherited from class java.lang.reflect.AccessibleObject

getAnnotations, isAccessible, isAnnotationPresent, setAccessible, setAccessible

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.lang.reflect.AnnotatedElement

getAnnotations, isAnnotationPresent

Method Detail

getDeclaringClass

public Class<?> getDeclaringClass()

getDeclaringClass returns the class this field was declared in.

Specified by:

getDeclaringClass in interface Member

Returns:

The class declaring this method.

See Also:

Member.getDeclaringClass()

getName

public String getName()

getName returns the name of this field.

Specified by:

getName in interface Member

Returns:

the name as a java string.

getModifiers

public int getModifiers()

getModifiers returns the set of modifiers set for this field.

Specified by:

getModifiers in interface Member

Returns:

the modifiers.

See Also:

Modifier

getType

public Class<?> getType()

getType returns the type of this field.

Returns:

the type, either a Java class, an array type or a primitive type such as Integer.TYPE.

equals

public boolean equals(Object obj)

equals checks if this field is equal to another field.

Overrides:

equals in class Object

Parameters:

obj - another object

Returns:

true iff obj is a field with the same declaring class, equal name and same type as this.

hashCode

public int hashCode()

hashCode returns a hash code for this field

Overrides:

hashCode in class Object

Returns:

getDeclaringClass().getName().hashCode() ^ getName().hashCode()

toString

public String toString()

toString converts this field to a string such as "public java.io.PrintStream java.lang.System.out".

Overrides:

toString in class Object

Returns:

a string representation of this field.

get

public Object get(Object obj)
           throws IllegalArgumentException,
                  IllegalAccessException

get returns the value of this field. If this field's declaring class is static and is not initialized, this class will be initialized first.

Parameters:

obj - the instance to take this value from in case of an instance field. Ignored in case of a static field access.

Returns:

the value of this field, boxed in case it is a primitive type.

Throws:

IllegalArgumentException - if this is an instance field and obj is not an instance of getDeclaringClass().

IllegalAccessException - if the caller does not have the right to access this field.

NullPointerException - if this is an instance field and obj is null.

ExceptionInInitializerError - if this is a static field and initialization of the declaring class failed.

getBoolean

public boolean getBoolean(Object obj)
                   throws IllegalArgumentException,
                          IllegalAccessException

getBoolean returns the value of this boolean field. If this field's declaring class is static and is not initialized, this class will be initialized first.

Parameters:

obj - the instance to take this value from in case of an instance field. Ignored in case of a static field access.

Returns:

the value of this field.

Throws:

IllegalArgumentException - if this is an instance field and obj is not an instance of getDeclaringClass() or this field's type is not boolean.

IllegalAccessException - if the caller does not have the right to access this field.

NullPointerException - if this is an instance field and obj is null.

ExceptionInInitializerError - if this is a static field and initialization of the declaring class failed.

getByte

public byte getByte(Object obj)
             throws IllegalArgumentException,
                    IllegalAccessException

getByte returns the value of this byte field. If this field's declaring class is static and is not initialized, this class will be initialized first.

Parameters:

obj - the instance to take this value from in case of an instance field. Ignored in case of a static field access.

Returns:

the value of this field.

Throws:

IllegalArgumentException - if this is an instance field and obj is not an instance of getDeclaringClass() or this field's type is not byte.

IllegalAccessException - if the caller does not have the right to access this field.

NullPointerException - if this is an instance field and obj is null.

ExceptionInInitializerError - if this is a static field and initialization of the declaring class failed.

getChar

public char getChar(Object obj)
             throws IllegalArgumentException,
                    IllegalAccessException

getChar returns the value of this char field. If this field's declaring class is static and is not initialized, this class will be initialized first.

Parameters:

obj - the instance to take this value from in case of an instance field. Ignored in case of a static field access.

Returns:

the value of this field.

Throws:

IllegalArgumentException - if this is an instance field and obj is not an instance of getDeclaringClass() or this field's type is not char.

IllegalAccessException - if the caller does not have the right to access this field.

NullPointerException - if this is an instance field and obj is null.

ExceptionInInitializerError - if this is a static field and initialization of the declaring class failed.

getShort

public short getShort(Object obj)
               throws IllegalArgumentException,
                      IllegalAccessException

getShort returns the value of this short field. If this field's declaring class is static and is not initialized, this class will be initialized first.

Parameters:

obj - the instance to take this value from in case of an instance field. Ignored in case of a static field access.

Returns:

the value of this field.

Throws:

IllegalArgumentException - if this is an instance field and obj is not an instance of getDeclaringClass() or this field's type is not short.

IllegalAccessException - if the caller does not have the right to access this field.

NullPointerException - if this is an instance field and obj is null.

ExceptionInInitializerError - if this is a static field and initialization of the declaring class failed.

getInt

public int getInt(Object obj)
           throws IllegalArgumentException,
                  IllegalAccessException

getInt returns the value of this int field. If this field's declaring class is static and is not initialized, this class will be initialized first.

Parameters:

obj - the instance to take this value from in case of an instance field. Ignored in case of a static field access.

Returns:

the value of this field.

Throws:

IllegalArgumentException - if this is an instance field and obj is not an instance of getDeclaringClass() or this field's type is not int.

IllegalAccessException - if the caller does not have the right to access this field.

NullPointerException - if this is an instance field and obj is null.

ExceptionInInitializerError - if this is a static field and initialization of the declaring class failed.

getLong

public long getLong(Object obj)
             throws IllegalArgumentException,
                    IllegalAccessException

getLong returns the value of this long field. If this field's declaring class is static and is not initialized, this class will be initialized first.

Parameters:

obj - the instance to take this value from in case of an instance field. Ignored in case of a static field access.

Returns:

the value of this field.

Throws:

IllegalArgumentException - if this is an instance field and obj is not an instance of getDeclaringClass() or this field's type is not long.

IllegalAccessException - if the caller does not have the right to access this field.

NullPointerException - if this is an instance field and obj is null.

ExceptionInInitializerError - if this is a static field and initialization of the declaring class failed.

getFloat

public float getFloat(Object obj)
               throws IllegalArgumentException,
                      IllegalAccessException

getFloat returns the value of this float field. If this field's declaring class is static and is not initialized, this class will be initialized first.

Parameters:

obj - the instance to take this value from in case of an instance field. Ignored in case of a static field access.

Returns:

the value of this field.

Throws:

IllegalArgumentException - if this is an instance field and obj is not an instance of getDeclaringClass() or this field's type is not float.

IllegalAccessException - if the caller does not have the right to access this field.

NullPointerException - if this is an instance field and obj is null.

ExceptionInInitializerError - if this is a static field and initialization of the declaring class failed.

getDouble

public double getDouble(Object obj)
                 throws IllegalArgumentException,
                        IllegalAccessException

getDouble returns the value of this doublue field. If this field's declaring class is static and is not initialized, this class will be initialized first.

Parameters:

obj - the instance to take this value from in case of an instance field. Ignored in case of a static field access.

Returns:

the value of this field.

Throws:

IllegalArgumentException - if this is an instance field and obj is not an instance of getDeclaringClass() or this field's type is not double.

IllegalAccessException - if the caller does not have the right to access this field.

NullPointerException - if this is an instance field and obj is null.

ExceptionInInitializerError - if this is a static field and initialization of the declaring class failed.

set

public void set(Object o,
                Object v)
         throws IllegalArgumentException,
                IllegalAccessException

set sets the value of this field. If this field's declaring class is static and is not initialized, this class will be initialized first.

Parameters:

o - the instance containing the field to be set in case of an instance field. Ignored in case of a static field access.

v - the new value of the field, boxed in case a field of primitive type is set.

Throws:

IllegalArgumentException - if this is an instance field and o is not an instance of getDeclaringClass() or if value could not be converted to the field type with a widening conversion.

IllegalAccessException - if the caller does not have the right to access this field.

NullPointerException - if this is an instance field and o is null.

ExceptionInInitializerError - if this is a static field and initialization of the declaring class failed.

setBoolean

public void setBoolean(Object obj,
                       boolean z)
                throws IllegalArgumentException,
                       IllegalAccessException

setBoolean sets the value of this field. If this field's declaring class is static and is not initialized, this class will be initialized first.

Parameters:

obj - the instance containing the field to be set in case of an instance field. Ignored in case of a static field access.

z - the new value of the field.

Throws:

IllegalArgumentException - if this is an instance field and o is not an instance of getDeclaringClass() or if this field's type is not boolean.

IllegalAccessException - if the caller does not have the right to access this field.

NullPointerException - if this is an instance field and o is null.

ExceptionInInitializerError - if this is a static field and initialization of the declaring class failed.

setByte

public void setByte(Object obj,
                    byte b)
             throws IllegalArgumentException,
                    IllegalAccessException

setByte sets the value of this field. If this field's declaring class is static and is not initialized, this class will be initialized first.

Parameters:

obj - the instance containing the field to be set in case of an instance field. Ignored in case of a static field access.

b - the new value of the field.

Throws:

IllegalArgumentException - if this is an instance field and o is not an instance of getDeclaringClass() or if this field's type is not byte.

IllegalAccessException - if the caller does not have the right to access this field.

NullPointerException - if this is an instance field and o is null.

ExceptionInInitializerError - if this is a static field and initialization of the declaring class failed.

setChar

public void setChar(Object obj,
                    char c)
             throws IllegalArgumentException,
                    IllegalAccessException

setChar sets the value of this field. If this field's declaring class is static and is not initialized, this class will be initialized first.

Parameters:

obj - the instance containing the field to be set in case of an instance field. Ignored in case of a static field access.

c - the new value of the field.

Throws:

IllegalArgumentException - if this is an instance field and o is not an instance of getDeclaringClass() or if this field's type is not char.

IllegalAccessException - if the caller does not have the right to access this field.

NullPointerException - if this is an instance field and o is null.

ExceptionInInitializerError - if this is a static field and initialization of the declaring class failed.

setShort

public void setShort(Object obj,
                     short s)
              throws IllegalArgumentException,
                     IllegalAccessException

setShort sets the value of this field. If this field's declaring class is static and is not initialized, this class will be initialized first.

Parameters:

obj - the instance containing the field to be set in case of an instance field. Ignored in case of a static field access.

s - the new value of the field.

Throws:

IllegalArgumentException - if this is an instance field and o is not an instance of getDeclaringClass() or if this field's type is not short.

IllegalAccessException - if the caller does not have the right to access this field.

NullPointerException - if this is an instance field and o is null.

ExceptionInInitializerError - if this is a static field and initialization of the declaring class failed.

setInt

public void setInt(Object obj,
                   int i)
            throws IllegalArgumentException,
                   IllegalAccessException

setInt sets the value of this field. If this field's declaring class is static and is not initialized, this class will be initialized first.

Parameters:

obj - the instance containing the field to be set in case of an instance field. Ignored in case of a static field access.

i - the new value of the field.

Throws:

IllegalArgumentException - if this is an instance field and o is not an instance of getDeclaringClass() or if this field's type is not int.

IllegalAccessException - if the caller does not have the right to access this field.

NullPointerException - if this is an instance field and o is null.

ExceptionInInitializerError - if this is a static field and initialization of the declaring class failed.

setLong

public void setLong(Object obj,
                    long l)
             throws IllegalArgumentException,
                    IllegalAccessException

setLong sets the value of this field. If this field's declaring class is static and is not initialized, this class will be initialized first.

Parameters:

obj - the instance containing the field to be set in case of an instance field. Ignored in case of a static field access.

l - the new value of the field.

Throws:

IllegalArgumentException - if this is an instance field and o is not an instance of getDeclaringClass() or if this field's type is not long.

IllegalAccessException - if the caller does not have the right to access this field.

NullPointerException - if this is an instance field and o is null.

ExceptionInInitializerError - if this is a static field and initialization of the declaring class failed.

setFloat

public void setFloat(Object obj,
                     float f)
              throws IllegalArgumentException,
                     IllegalAccessException

setFloat sets the value of this field. If this field's declaring class is static and is not initialized, this class will be initialized first.

Parameters:

obj - the instance containing the field to be set in case of an instance field. Ignored in case of a static field access.

f - the new value of the field.

Throws:

IllegalArgumentException - if this is an instance field and o is not an instance of getDeclaringClass() or if this field's type is not float.

IllegalAccessException - if the caller does not have the right to access this field.

NullPointerException - if this is an instance field and o is null.

ExceptionInInitializerError - if this is a static field and initialization of the declaring class failed.

setDouble

public void setDouble(Object obj,
                      double d)
               throws IllegalArgumentException,
                      IllegalAccessException

setDouble sets the value of this field. If this field's declaring class is static and is not initialized, this class will be initialized first.

Parameters:

obj - the instance containing the field to be set in case of an instance field. Ignored in case of a static field access.

d - the new value of the field.

Throws:

IllegalArgumentException - if this is an instance field and o is not an instance of getDeclaringClass() or if this field's type is not double.

IllegalAccessException - if the caller does not have the right to access this field.

NullPointerException - if this is an instance field and o is null.

ExceptionInInitializerError - if this is a static field and initialization of the declaring class failed.

isEnumConstant

public boolean isEnumConstant()

isEnumConstant

NYI: COMMENT: JDK 1.5 method description

Returns:

true if and only if this field represents an element of an enumerated type.

Since:

1.5

isSynthetic

public boolean isSynthetic()

isSynthetic

NYI: COMMENT: JDK 1.5 method description

Specified by:

isSynthetic in interface Member

Returns:

true if and only if this field is a synthetic field as defined by the Java Language Specification.

Since:

1.5

getGenericType

public Type getGenericType()

getGenericType

NYI: COMMENT: JDK 1.5 method description

Returns:

a Type object that represents the declared type for the field represented by this Field object

Since:

1.5

toGenericString

public String toGenericString()

toGenericString

NYI: COMMENT: JDK 1.5 method description

Returns:

a string describing this Field, including its generic type

Since:

1.5

getAnnotation

public <T extends Annotation> T getAnnotation(Class<T> annotationType)

getAnnotation

NYI: COMMENT: JDK 1.5 method description

Specified by:

getAnnotation in interface AnnotatedElement

Overrides:

getAnnotation in class AccessibleObject

Parameters:

annotationType -

Returns:

this element's annotation for the specified annotation type if present on this element, else null

Since:

1.5

getDeclaredAnnotations

public Annotation[] getDeclaredAnnotations()

getDeclaredAnnotations

NYI: COMMENT: JDK 1.5 method description

Specified by:

getDeclaredAnnotations in interface AnnotatedElement

Overrides:

getDeclaredAnnotations in class AccessibleObject

Returns:

All annotations directly present on this element

Since:

1.5