Module de.cuioss.java.tools

Package de.cuioss.tools.reflect

Class FieldWrapper

java.lang.Object

de.cuioss.tools.reflect.FieldWrapper

public class FieldWrapper
extends Object

Wrapper around a Field that handles implicitly the accessible flag for access.

Author:

Oliver Wolff

Constructor Summary

Constructors

Constructor	Description
FieldWrapper(Field field)

Method Summary

Modifier and Type	Method	Description
static final Optional<FieldWrapper>	from(Class<?> type, String fieldName)	Factory Method for creating an FieldWrapper instance
Optional<Object>	readValue(Object object)	Reads from the field determined by #getField().
static final Optional<Object>	readValue(String fieldName, Object object)	Reads the value from the field in the given object.
void	writeValue(@NonNull Object object, Object value)	Writes to the field determined by #getField().

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

FieldWrapper

public FieldWrapper(Field field)

Parameters:

field - must not be null

Method Details

readValue

public Optional<Object> readValue(Object object)

Reads from the field determined by #getField(). It implicitly sets and resets the AccessibleObject.isAccessible() flag.

Parameters:

object - to be read from

Returns:

an Optional on the given field value if applicable. May return Optional.empty() for cases where:

• Field value is null
• Given Object is null
• Given Object is improper type
• an IllegalAccessException occurred while accessing

readValue

public static final Optional<Object> readValue(String fieldName,
 Object object)

Reads the value from the field in the given object. It implicitly sets and resets the AccessibleObject.isAccessible() flag.

Parameters:

fieldName - to be read

object - to be read from

Returns:

the field value. Optional.empty() if the field cannot be read.

writeValue

public void writeValue(@NonNull
 @NonNull Object object,
 Object value)

Writes to the field determined by #getField(). It implicitly sets and resets the AccessibleObject.isAccessible() flag.

Parameters:

object - to be written to, must not be null

value - to be written, may be null

Throws:

NullPointerException - in case object is null

IllegalArgumentException - in case the value is not applicable to the field

IllegalStateException - wrapping an IllegalAccessException

from

public static final Optional<FieldWrapper> from(Class<?> type,
 String fieldName)

Factory Method for creating an FieldWrapper instance

Parameters:

type - must not be null

fieldName - must not be null

Returns:

a FieldWrapper if the Field can be determined, Optional.empty() otherwise