Package io.cui.tools.reflect

Class FieldWrapper

java.lang.Object

io.cui.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 Optional<FieldWrapper>	from(Class<?> type, String fieldName)	Factory Method for creating an FieldWrapper instance
@NonNull Field	getField()
Optional<Object>	readValue(Object object)	Reads from the field determined by getField().
static 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 Detail

FieldWrapper

public FieldWrapper(Field field)

Parameters:

field - must not be null

Method Detail

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

getField

@NonNull
public @NonNull Field getField()