FieldUtils (Apache Commons Lang 3.3.2 API)

java.lang.Object
- org.apache.commons.lang3.reflect.FieldUtils

```
public class FieldUtils
extends Object
```
Utilities for working with Fields by reflection. Adapted and refactored from the dormant [reflect] Commons sandbox component.
The ability is provided to break the scoping restrictions coded by the programmer. This can allow fields to be changed that shouldn't be. This facility should be used with care.

Since:

2.5

Version:

$Id: FieldUtils.java 1583482 2014-03-31 22:54:57Z niallp $

Constructor Summary

Constructors
Constructor and Description

FieldUtils()
FieldUtils instances should NOT be constructed in standard programming.

Constructors
Constructor and Description
`FieldUtils()` `FieldUtils` instances should NOT be constructed in standard programming.

Method Summary

Methods
Modifier and Type	Method and Description
`static Field[]`	`getAllFields(Class<?> cls)` Gets all fields of the given class and its parents (if any).
`static List<Field>`	`getAllFieldsList(Class<?> cls)` Gets all fields of the given class and its parents (if any).
`static Field`	`getDeclaredField(Class<?> cls, String fieldName)` Gets an accessible `Field` by name respecting scope.
`static Field`	`getDeclaredField(Class<?> cls, String fieldName, boolean forceAccess)` Gets an accessible `Field` by name, breaking scope if requested.
`static Field`	`getField(Class<?> cls, String fieldName)` Gets an accessible `Field` by name respecting scope.
`static Field`	`getField(Class<?> cls, String fieldName, boolean forceAccess)` Gets an accessible `Field` by name, breaking scope if requested.
`static Object`	`readDeclaredField(Object target, String fieldName)` Reads the named `public` `Field`.
`static Object`	`readDeclaredField(Object target, String fieldName, boolean forceAccess)` Gets a `Field` value by name.
`static Object`	`readDeclaredStaticField(Class<?> cls, String fieldName)` Gets the value of a `static` `Field` by name.
`static Object`	`readDeclaredStaticField(Class<?> cls, String fieldName, boolean forceAccess)` Gets the value of a `static` `Field` by name.
`static Object`	`readField(Field field, Object target)` Reads an accessible `Field`.
`static Object`	`readField(Field field, Object target, boolean forceAccess)` Reads a `Field`.
`static Object`	`readField(Object target, String fieldName)` Reads the named `public` `Field`.
`static Object`	`readField(Object target, String fieldName, boolean forceAccess)` Reads the named `Field`.
`static Object`	`readStaticField(Class<?> cls, String fieldName)` Reads the named `public static` `Field`.
`static Object`	`readStaticField(Class<?> cls, String fieldName, boolean forceAccess)` Reads the named `static` `Field`.
`static Object`	`readStaticField(Field field)` Reads an accessible `static` `Field`.
`static Object`	`readStaticField(Field field, boolean forceAccess)` Reads a static `Field`.
`static void`	`removeFinalModifier(Field field)` Removes the final modifier from a `Field`.
`static void`	`removeFinalModifier(Field field, boolean forceAccess)` Removes the final modifier from a `Field`.
`static void`	`writeDeclaredField(Object target, String fieldName, Object value)` Writes a `public` `Field`.
`static void`	`writeDeclaredField(Object target, String fieldName, Object value, boolean forceAccess)` Writes a `public` `Field`.
`static void`	`writeDeclaredStaticField(Class<?> cls, String fieldName, Object value)` Writes a named `public static` `Field`.
`static void`	`writeDeclaredStaticField(Class<?> cls, String fieldName, Object value, boolean forceAccess)` Writes a named `static` `Field`.
`static void`	`writeField(Field field, Object target, Object value)` Writes an accessible `Field`.
`static void`	`writeField(Field field, Object target, Object value, boolean forceAccess)` Writes a `Field`.
`static void`	`writeField(Object target, String fieldName, Object value)` Writes a `public` `Field`.
`static void`	`writeField(Object target, String fieldName, Object value, boolean forceAccess)` Writes a `Field`.
`static void`	`writeStaticField(Class<?> cls, String fieldName, Object value)` Writes a named `public static` `Field`.
`static void`	`writeStaticField(Class<?> cls, String fieldName, Object value, boolean forceAccess)` Writes a named `static` `Field`.
`static void`	`writeStaticField(Field field, Object value)` Writes a `public static` `Field`.
`static void`	`writeStaticField(Field field, Object value, boolean forceAccess)` Writes a static `Field`.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - FieldUtils
```
public FieldUtils()
```
    FieldUtils instances should NOT be constructed in standard programming.
    This constructor is public to permit tools that require a JavaBean instance to operate.
- Method Detail
  - getField
```
public static Field getField(Class<?> cls,
             String fieldName)
```
    Gets an accessible Field by name respecting scope. Superclasses/interfaces will be considered.
    
    Parameters:
    cls - the Class to reflect, must not be null
    fieldName - the field name to obtain
    
    Returns:
    the Field object
    
    Throws:
    
    IllegalArgumentException - if the class is null, or the field name is blank or empty
  - getField
```
public static Field getField(Class<?> cls,
             String fieldName,
             boolean forceAccess)
```
    Gets an accessible Field by name, breaking scope if requested. Superclasses/interfaces will be considered.
    
    Parameters:
    cls - the Class to reflect, must not be null
    fieldName - the field name to obtain
    forceAccess - whether to break scope restrictions using the AccessibleObject.setAccessible(boolean) method. false will only match public fields.
    
    Returns:
    the Field object
    
    Throws:
    
    IllegalArgumentException - if the class is null, or the field name is blank or empty or is matched at multiple places in the inheritance hierarchy
  - getDeclaredField
```
public static Field getDeclaredField(Class<?> cls,
                     String fieldName)
```
    Gets an accessible Field by name respecting scope. Only the specified class will be considered.
    
    Parameters:
    cls - the Class to reflect, must not be null
    fieldName - the field name to obtain
    
    Returns:
    the Field object
    
    Throws:
    
    IllegalArgumentException - if the class is null, or the field name is blank or empty
  - getDeclaredField
```
public static Field getDeclaredField(Class<?> cls,
                     String fieldName,
                     boolean forceAccess)
```
    Gets an accessible Field by name, breaking scope if requested. Only the specified class will be considered.
    
    Parameters:
    cls - the Class to reflect, must not be null
    fieldName - the field name to obtain
    forceAccess - whether to break scope restrictions using the AccessibleObject.setAccessible(boolean) method. false will only match public fields.
    
    Returns:
    the Field object
    
    Throws:
    
    IllegalArgumentException - if the class is null, or the field name is blank or empty
  - getAllFields
```
public static Field[] getAllFields(Class<?> cls)
```
    Gets all fields of the given class and its parents (if any).
    
    Parameters:
    cls - the Class to query
    
    Returns:
    an array of Fields (possibly empty).
    
    Throws:
    
    IllegalArgumentException - if the class is null
    Since:
    
    3.2
  - getAllFieldsList
```
public static List<Field> getAllFieldsList(Class<?> cls)
```
    Gets all fields of the given class and its parents (if any).
    
    Parameters:
    cls - the Class to query
    
    Returns:
    an array of Fields (possibly empty).
    
    Throws:
    
    IllegalArgumentException - if the class is null
    Since:
    
    3.2
  - readStaticField
```
public static Object readStaticField(Field field)
                              throws IllegalAccessException
```
    Reads an accessible static Field.
    
    Parameters:
    field - to read
    
    Returns:
    the field value
    
    Throws:
    
    IllegalArgumentException - if the field is null, or not static
    
    IllegalAccessException - if the field is not accessible
  - readStaticField
```
public static Object readStaticField(Field field,
                     boolean forceAccess)
                              throws IllegalAccessException
```
    Reads a static Field.
    
    Parameters:
    field - to read
    forceAccess - whether to break scope restrictions using the AccessibleObject.setAccessible(boolean) method.
    
    Returns:
    the field value
    
    Throws:
    
    IllegalArgumentException - if the field is null or not static
    
    IllegalAccessException - if the field is not made accessible
  - readStaticField
```
public static Object readStaticField(Class<?> cls,
                     String fieldName)
                              throws IllegalAccessException
```
    Reads the named public static Field. Superclasses will be considered.
    
    Parameters:
    cls - the Class to reflect, must not be null
    fieldName - the field name to obtain
    
    Returns:
    the value of the field
    
    Throws:
    
    IllegalArgumentException - if the class is null, or the field name is blank or empty, is not static, or could not be found
    
    IllegalAccessException - if the field is not accessible
  - readStaticField
```
public static Object readStaticField(Class<?> cls,
                     String fieldName,
                     boolean forceAccess)
                              throws IllegalAccessException
```
    Reads the named static Field. Superclasses will be considered.
    
    Parameters:
    cls - the Class to reflect, must not be null
    fieldName - the field name to obtain
    forceAccess - whether to break scope restrictions using the AccessibleObject.setAccessible(boolean) method. false will only match public fields.
    
    Returns:
    the Field object
    
    Throws:
    
    IllegalArgumentException - if the class is null, or the field name is blank or empty, is not static, or could not be found
    
    IllegalAccessException - if the field is not made accessible
  - readDeclaredStaticField
```
public static Object readDeclaredStaticField(Class<?> cls,
                             String fieldName)
                                      throws IllegalAccessException
```
    Gets the value of a static Field by name. The field must be public. Only the specified class will be considered.
    
    Parameters:
    cls - the Class to reflect, must not be null
    fieldName - the field name to obtain
    
    Returns:
    the value of the field
    
    Throws:
    
    IllegalArgumentException - if the class is null, or the field name is blank or empty, is not static, or could not be found
    
    IllegalAccessException - if the field is not accessible
  - readDeclaredStaticField
```
public static Object readDeclaredStaticField(Class<?> cls,
                             String fieldName,
                             boolean forceAccess)
                                      throws IllegalAccessException
```
    Gets the value of a static Field by name. Only the specified class will be considered.
    
    Parameters:
    cls - the Class to reflect, must not be null
    fieldName - the field name to obtain
    forceAccess - whether to break scope restrictions using the AccessibleObject.setAccessible(boolean) method. false will only match public fields.
    
    Returns:
    the Field object
    
    Throws:
    
    IllegalArgumentException - if the class is null, or the field name is blank or empty, is not static, or could not be found
    
    IllegalAccessException - if the field is not made accessible
  - readField
```
public static Object readField(Field field,
               Object target)
                        throws IllegalAccessException
```
    Reads an accessible Field.
    
    Parameters:
    field - the field to use
    target - the object to call on, may be null for static fields
    
    Returns:
    the field value
    
    Throws:
    
    IllegalArgumentException - if the field is null
    
    IllegalAccessException - if the field is not accessible
  - readField
```
public static Object readField(Field field,
               Object target,
               boolean forceAccess)
                        throws IllegalAccessException
```
    Reads a Field.
    
    Parameters:
    field - the field to use
    target - the object to call on, may be null for static fields
    forceAccess - whether to break scope restrictions using the AccessibleObject.setAccessible(boolean) method.
    
    Returns:
    the field value
    
    Throws:
    
    IllegalArgumentException - if the field is null
    
    IllegalAccessException - if the field is not made accessible
  - readField
```
public static Object readField(Object target,
               String fieldName)
                        throws IllegalAccessException
```
    Reads the named public Field. Superclasses will be considered.
    
    Parameters:
    target - the object to reflect, must not be null
    fieldName - the field name to obtain
    
    Returns:
    the value of the field
    
    Throws:
    
    IllegalArgumentException - if the class is null, or the field name is blank or empty or could not be found
    
    IllegalAccessException - if the named field is not public
  - readField
```
public static Object readField(Object target,
               String fieldName,
               boolean forceAccess)
                        throws IllegalAccessException
```
    Reads the named Field. Superclasses will be considered.
    
    Parameters:
    target - the object to reflect, must not be null
    fieldName - the field name to obtain
    forceAccess - whether to break scope restrictions using the AccessibleObject.setAccessible(boolean) method. false will only match public fields.
    
    Returns:
    the field value
    
    Throws:
    
    IllegalArgumentException - if target is null, or the field name is blank or empty or could not be found
    
    IllegalAccessException - if the named field is not made accessible
  - readDeclaredField
```
public static Object readDeclaredField(Object target,
                       String fieldName)
                                throws IllegalAccessException
```
    Reads the named public Field. Only the class of the specified object will be considered.
    
    Parameters:
    target - the object to reflect, must not be null
    fieldName - the field name to obtain
    
    Returns:
    the value of the field
    
    Throws:
    
    IllegalArgumentException - if target is null, or the field name is blank or empty or could not be found
    
    IllegalAccessException - if the named field is not public
  - readDeclaredField
```
public static Object readDeclaredField(Object target,
                       String fieldName,
                       boolean forceAccess)
                                throws IllegalAccessException
```
    Gets a Field value by name. Only the class of the specified object will be considered.
    
    Parameters:
    target - the object to reflect, must not be null
    fieldName - the field name to obtain
    forceAccess - whether to break scope restrictions using the AccessibleObject.setAccessible(boolean) method. false will only match public fields.
    
    Returns:
    the Field object
    
    Throws:
    
    IllegalArgumentException - if target is null, or the field name is blank or empty or could not be found
    
    IllegalAccessException - if the field is not made accessible
  - writeStaticField
```
public static void writeStaticField(Field field,
                    Object value)
                             throws IllegalAccessException
```
    Writes a public static Field.
    
    Parameters:
    field - to write
    value - to set
    
    Throws:
    
    IllegalArgumentException - if the field is null or not static, or value is not assignable
    
    IllegalAccessException - if the field is not public or is final
  - writeStaticField
```
public static void writeStaticField(Field field,
                    Object value,
                    boolean forceAccess)
                             throws IllegalAccessException
```
    Writes a static Field.
    
    Parameters:
    field - to write
    value - to set
    forceAccess - whether to break scope restrictions using the AccessibleObject.setAccessible(boolean) method. false will only match public fields.
    
    Throws:
    
    IllegalArgumentException - if the field is null or not static, or value is not assignable
    
    IllegalAccessException - if the field is not made accessible or is final
  - writeStaticField
```
public static void writeStaticField(Class<?> cls,
                    String fieldName,
                    Object value)
                             throws IllegalAccessException
```
    Writes a named public static Field. Superclasses will be considered.
    
    Parameters:
    cls - Class on which the field is to be found
    fieldName - to write
    value - to set
    
    Throws:
    
    IllegalArgumentException - if cls is null, the field name is blank or empty, the field cannot be located or is not static, or value is not assignable
    
    IllegalAccessException - if the field is not public or is final
  - writeStaticField
```
public static void writeStaticField(Class<?> cls,
                    String fieldName,
                    Object value,
                    boolean forceAccess)
                             throws IllegalAccessException
```
    Writes a named static Field. Superclasses will be considered.
    
    Parameters:
    cls - Class on which the field is to be found
    fieldName - to write
    value - to set
    forceAccess - whether to break scope restrictions using the AccessibleObject.setAccessible(boolean) method. false will only match public fields.
    
    Throws:
    
    IllegalArgumentException - if cls is null, the field name is blank or empty, the field cannot be located or is not static, or value is not assignable
    
    IllegalAccessException - if the field is not made accessible or is final
  - writeDeclaredStaticField
```
public static void writeDeclaredStaticField(Class<?> cls,
                            String fieldName,
                            Object value)
                                     throws IllegalAccessException
```
    Writes a named public static Field. Only the specified class will be considered.
    
    Parameters:
    cls - Class on which the field is to be found
    fieldName - to write
    value - to set
    
    Throws:
    
    IllegalArgumentException - if cls is null, the field name is blank or empty, the field cannot be located or is not static, or value is not assignable
    
    IllegalAccessException - if the field is not public or is final
  - writeDeclaredStaticField
```
public static void writeDeclaredStaticField(Class<?> cls,
                            String fieldName,
                            Object value,
                            boolean forceAccess)
                                     throws IllegalAccessException
```
    Writes a named static Field. Only the specified class will be considered.
    
    Parameters:
    cls - Class on which the field is to be found
    fieldName - to write
    value - to set
    forceAccess - whether to break scope restrictions using the AccessibleObject#setAccessible(boolean) method. false will only match public fields.
    
    Throws:
    
    IllegalArgumentException - if cls is null, the field name is blank or empty, the field cannot be located or is not static, or value is not assignable
    
    IllegalAccessException - if the field is not made accessible or is final
  - writeField
```
public static void writeField(Field field,
              Object target,
              Object value)
                       throws IllegalAccessException
```
    Writes an accessible Field.
    
    Parameters:
    field - to write
    target - the object to call on, may be null for static fields
    value - to set
    
    Throws:
    
    IllegalAccessException - if the field or target is null, the field is not accessible or is final, or value is not assignable
  - writeField
```
public static void writeField(Field field,
              Object target,
              Object value,
              boolean forceAccess)
                       throws IllegalAccessException
```
    Writes a Field.
    
    Parameters:
    field - to write
    target - the object to call on, may be null for static fields
    value - to set
    forceAccess - whether to break scope restrictions using the AccessibleObject.setAccessible(boolean) method. false will only match public fields.
    
    Throws:
    
    IllegalArgumentException - if the field is null or value is not assignable
    
    IllegalAccessException - if the field is not made accessible or is final
  - removeFinalModifier
```
public static void removeFinalModifier(Field field)
```
    Removes the final modifier from a Field.
    
    Parameters:
    field - to remove the final modifier
    
    Throws:
    
    IllegalArgumentException - if the field is null
    Since:
    
    3.2
  - removeFinalModifier
```
public static void removeFinalModifier(Field field,
                       boolean forceAccess)
```
    Removes the final modifier from a Field.
    
    Parameters:
    field - to remove the final modifier
    forceAccess - whether to break scope restrictions using the AccessibleObject.setAccessible(boolean) method. false will only match public fields.
    
    Throws:
    
    IllegalArgumentException - if the field is null
    Since:
    
    3.3
  - writeField
```
public static void writeField(Object target,
              String fieldName,
              Object value)
                       throws IllegalAccessException
```
    Writes a public Field. Superclasses will be considered.
    
    Parameters:
    target - the object to reflect, must not be null
    fieldName - the field name to obtain
    value - to set
    
    Throws:
    
    IllegalArgumentException - if target is null, fieldName is blank or empty or could not be found, or value is not assignable
    
    IllegalAccessException - if the field is not accessible
  - writeField
```
public static void writeField(Object target,
              String fieldName,
              Object value,
              boolean forceAccess)
                       throws IllegalAccessException
```
    Writes a Field. Superclasses will be considered.
    
    Parameters:
    target - the object to reflect, must not be null
    fieldName - the field name to obtain
    value - to set
    forceAccess - whether to break scope restrictions using the AccessibleObject.setAccessible(boolean) method. false will only match public fields.
    
    Throws:
    
    IllegalArgumentException - if target is null, fieldName is blank or empty or could not be found, or value is not assignable
    
    IllegalAccessException - if the field is not made accessible
  - writeDeclaredField
```
public static void writeDeclaredField(Object target,
                      String fieldName,
                      Object value)
                               throws IllegalAccessException
```
    Writes a public Field. Only the specified class will be considered.
    
    Parameters:
    target - the object to reflect, must not be null
    fieldName - the field name to obtain
    value - to set
    
    Throws:
    
    IllegalArgumentException - if target is null, fieldName is blank or empty or could not be found, or value is not assignable
    
    IllegalAccessException - if the field is not made accessible
  - writeDeclaredField
```
public static void writeDeclaredField(Object target,
                      String fieldName,
                      Object value,
                      boolean forceAccess)
                               throws IllegalAccessException
```
    Writes a public Field. Only the specified class will be considered.
    
    Parameters:
    target - the object to reflect, must not be null
    fieldName - the field name to obtain
    value - to set
    forceAccess - whether to break scope restrictions using the AccessibleObject.setAccessible(boolean) method. false will only match public fields.
    
    Throws:
    
    IllegalArgumentException - if target is null, fieldName is blank or empty or could not be found, or value is not assignable
    
    IllegalAccessException - if the field is not made accessible

Class FieldUtils

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

FieldUtils

Method Detail

getField

getField

getDeclaredField

getDeclaredField

getAllFields

getAllFieldsList

readStaticField

readStaticField

readStaticField

readStaticField

readDeclaredStaticField

readDeclaredStaticField

readField

readField

readField

readField

readDeclaredField

readDeclaredField

writeStaticField

writeStaticField

writeStaticField

writeStaticField

writeDeclaredStaticField

writeDeclaredStaticField

writeField

writeField

removeFinalModifier

removeFinalModifier

writeField

writeField

writeDeclaredField

writeDeclaredField