Package org.apache.commons.lang.reflect

Class FieldUtils

  • public class FieldUtils
extends java.lang.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

    • Constructor Summary

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

    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static java.lang.reflect.Field getDeclaredField​(java.lang.Class cls, java.lang.String fieldName)
      Gets an accessible Field by name respecting scope.
      static java.lang.reflect.Field getDeclaredField​(java.lang.Class cls, java.lang.String fieldName, boolean forceAccess)
      Gets an accessible Field by name breaking scope if requested.
      static java.lang.reflect.Field getField​(java.lang.Class cls, java.lang.String fieldName)
      Gets an accessible Field by name respecting scope.
      static java.lang.reflect.Field getField​(java.lang.Class cls, java.lang.String fieldName, boolean forceAccess)
      Gets an accessible Field by name breaking scope if requested.
      static java.lang.Object readDeclaredField​(java.lang.Object target, java.lang.String fieldName)
      Read the named public field.
      static java.lang.Object readDeclaredField​(java.lang.Object target, java.lang.String fieldName, boolean forceAccess)
      Gets a Field value by name.
      static java.lang.Object readDeclaredStaticField​(java.lang.Class cls, java.lang.String fieldName)
      Gets a static Field value by name.
      static java.lang.Object readDeclaredStaticField​(java.lang.Class cls, java.lang.String fieldName, boolean forceAccess)
      Gets a static Field value by name.
      static java.lang.Object readField​(java.lang.Object target, java.lang.String fieldName)
      Read the named public field.
      static java.lang.Object readField​(java.lang.Object target, java.lang.String fieldName, boolean forceAccess)
      Read the named field.
      static java.lang.Object readField​(java.lang.reflect.Field field, java.lang.Object target)
      Read an accessible Field.
      static java.lang.Object readField​(java.lang.reflect.Field field, java.lang.Object target, boolean forceAccess)
      Read a Field.
      static java.lang.Object readStaticField​(java.lang.Class cls, java.lang.String fieldName)
      Read the named public static field.
      static java.lang.Object readStaticField​(java.lang.Class cls, java.lang.String fieldName, boolean forceAccess)
      Read the named static field.
      static java.lang.Object readStaticField​(java.lang.reflect.Field field)
      Read an accessible static Field.
      static java.lang.Object readStaticField​(java.lang.reflect.Field field, boolean forceAccess)
      Read a static Field.
      static void writeDeclaredField​(java.lang.Object target, java.lang.String fieldName, java.lang.Object value)
      Write a public field.
      static void writeDeclaredField​(java.lang.Object target, java.lang.String fieldName, java.lang.Object value, boolean forceAccess)
      Write a public field.
      static void writeDeclaredStaticField​(java.lang.Class cls, java.lang.String fieldName, java.lang.Object value)
      Write a named public static Field.
      static void writeDeclaredStaticField​(java.lang.Class cls, java.lang.String fieldName, java.lang.Object value, boolean forceAccess)
      Write a named static Field.
      static void writeField​(java.lang.Object target, java.lang.String fieldName, java.lang.Object value)
      Write a public field.
      static void writeField​(java.lang.Object target, java.lang.String fieldName, java.lang.Object value, boolean forceAccess)
      Write a field.
      static void writeField​(java.lang.reflect.Field field, java.lang.Object target, java.lang.Object value)
      Write an accessible field.
      static void writeField​(java.lang.reflect.Field field, java.lang.Object target, java.lang.Object value, boolean forceAccess)
      Write a field.
      static void writeStaticField​(java.lang.Class cls, java.lang.String fieldName, java.lang.Object value)
      Write a named public static Field.
      static void writeStaticField​(java.lang.Class cls, java.lang.String fieldName, java.lang.Object value, boolean forceAccess)
      Write a named static Field.
      static void writeStaticField​(java.lang.reflect.Field field, java.lang.Object value)
      Write a public static Field.
      static void writeStaticField​(java.lang.reflect.Field field, java.lang.Object value, boolean forceAccess)
      Write a static Field.

      • Methods inherited from class java.lang.Object

        equals, 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 java.lang.reflect.Field getField​(java.lang.Class cls,
                                               java.lang.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:
        java.lang.IllegalArgumentException - if the class or field name is null

      • getField

        public static java.lang.reflect.Field getField​(java.lang.Class cls,
                                               java.lang.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 setAccessible method. False will only match public fields.
        Returns:
        the Field object
        Throws:
        java.lang.IllegalArgumentException - if the class or field name is null

      • getDeclaredField

        public static java.lang.reflect.Field getDeclaredField​(java.lang.Class cls,
                                                       java.lang.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:
        java.lang.IllegalArgumentException - if the class or field name is null

      • getDeclaredField

        public static java.lang.reflect.Field getDeclaredField​(java.lang.Class cls,
                                                       java.lang.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 setAccessible method. False will only match public fields.
        Returns:
        the Field object
        Throws:
        java.lang.IllegalArgumentException - if the class or field name is null

      • readStaticField

        public static java.lang.Object readStaticField​(java.lang.reflect.Field field)
                                        throws java.lang.IllegalAccessException
        Read an accessible static Field.
        Parameters:
        field - to read
        Returns:
        the field value
        Throws:
        java.lang.IllegalArgumentException - if the field is null or not static
        java.lang.IllegalAccessException - if the field is not accessible

      • readStaticField

        public static java.lang.Object readStaticField​(java.lang.reflect.Field field,
                                               boolean forceAccess)
                                        throws java.lang.IllegalAccessException
        Read a static Field.
        Parameters:
        field - to read
        forceAccess - whether to break scope restrictions using the setAccessible method.
        Returns:
        the field value
        Throws:
        java.lang.IllegalArgumentException - if the field is null or not static
        java.lang.IllegalAccessException - if the field is not made accessible

      • readStaticField

        public static java.lang.Object readStaticField​(java.lang.Class cls,
                                               java.lang.String fieldName)
                                        throws java.lang.IllegalAccessException
        Read 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:
        java.lang.IllegalArgumentException - if the class or field name is null
        java.lang.IllegalAccessException - if the field is not accessible

      • readStaticField

        public static java.lang.Object readStaticField​(java.lang.Class cls,
                                               java.lang.String fieldName,
                                               boolean forceAccess)
                                        throws java.lang.IllegalAccessException
        Read 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 setAccessible method. False will only match public fields.
        Returns:
        the Field object
        Throws:
        java.lang.IllegalArgumentException - if the class or field name is null
        java.lang.IllegalAccessException - if the field is not made accessible

      • readDeclaredStaticField

        public static java.lang.Object readDeclaredStaticField​(java.lang.Class cls,
                                                       java.lang.String fieldName)
                                                throws java.lang.IllegalAccessException
        Gets a static Field value 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:
        java.lang.IllegalArgumentException - if the class or field name is null
        java.lang.IllegalAccessException - if the field is not accessible

      • readDeclaredStaticField

        public static java.lang.Object readDeclaredStaticField​(java.lang.Class cls,
                                                       java.lang.String fieldName,
                                                       boolean forceAccess)
                                                throws java.lang.IllegalAccessException
        Gets a static Field value 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 setAccessible method. False will only match public fields.
        Returns:
        the Field object
        Throws:
        java.lang.IllegalArgumentException - if the class or field name is null
        java.lang.IllegalAccessException - if the field is not made accessible

      • readField

        public static java.lang.Object readField​(java.lang.reflect.Field field,
                                         java.lang.Object target)
                                  throws java.lang.IllegalAccessException
        Read 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:
        java.lang.IllegalArgumentException - if the field is null
        java.lang.IllegalAccessException - if the field is not accessible

      • readField

        public static java.lang.Object readField​(java.lang.reflect.Field field,
                                         java.lang.Object target,
                                         boolean forceAccess)
                                  throws java.lang.IllegalAccessException
        Read 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 setAccessible method.
        Returns:
        the field value
        Throws:
        java.lang.IllegalArgumentException - if the field is null
        java.lang.IllegalAccessException - if the field is not made accessible

      • readField

        public static java.lang.Object readField​(java.lang.Object target,
                                         java.lang.String fieldName)
                                  throws java.lang.IllegalAccessException
        Read 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:
        java.lang.IllegalArgumentException - if the class or field name is null
        java.lang.IllegalAccessException - if the named field is not public

      • readField

        public static java.lang.Object readField​(java.lang.Object target,
                                         java.lang.String fieldName,
                                         boolean forceAccess)
                                  throws java.lang.IllegalAccessException
        Read 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 setAccessible method. False will only match public fields.
        Returns:
        the field value
        Throws:
        java.lang.IllegalArgumentException - if the class or field name is null
        java.lang.IllegalAccessException - if the named field is not made accessible

      • readDeclaredField

        public static java.lang.Object readDeclaredField​(java.lang.Object target,
                                                 java.lang.String fieldName)
                                          throws java.lang.IllegalAccessException
        Read 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:
        java.lang.IllegalArgumentException - if the class or field name is null
        java.lang.IllegalAccessException - if the named field is not public

      • readDeclaredField

        public static java.lang.Object readDeclaredField​(java.lang.Object target,
                                                 java.lang.String fieldName,
                                                 boolean forceAccess)
                                          throws java.lang.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 setAccessible method. False will only match public fields.
        Returns:
        the Field object
        Throws:
        java.lang.IllegalArgumentException - if target or fieldName is null
        java.lang.IllegalAccessException - if the field is not made accessible

      • writeStaticField

        public static void writeStaticField​(java.lang.reflect.Field field,
                                    java.lang.Object value)
                             throws java.lang.IllegalAccessException
        Write a public static Field.
        Parameters:
        field - to write
        value - to set
        Throws:
        java.lang.IllegalArgumentException - if the field is null or not static
        java.lang.IllegalAccessException - if the field is not public or is final

      • writeStaticField

        public static void writeStaticField​(java.lang.reflect.Field field,
                                    java.lang.Object value,
                                    boolean forceAccess)
                             throws java.lang.IllegalAccessException
        Write a static Field.
        Parameters:
        field - to write
        value - to set
        forceAccess - whether to break scope restrictions using the setAccessible method. False will only match public fields.
        Throws:
        java.lang.IllegalArgumentException - if the field is null or not static
        java.lang.IllegalAccessException - if the field is not made accessible or is final

      • writeStaticField

        public static void writeStaticField​(java.lang.Class cls,
                                    java.lang.String fieldName,
                                    java.lang.Object value)
                             throws java.lang.IllegalAccessException
        Write 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:
        java.lang.IllegalArgumentException - if the field cannot be located or is not static
        java.lang.IllegalAccessException - if the field is not public or is final

      • writeStaticField

        public static void writeStaticField​(java.lang.Class cls,
                                    java.lang.String fieldName,
                                    java.lang.Object value,
                                    boolean forceAccess)
                             throws java.lang.IllegalAccessException
        Write 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 setAccessible method. False will only match public fields.
        Throws:
        java.lang.IllegalArgumentException - if the field cannot be located or is not static
        java.lang.IllegalAccessException - if the field is not made accessible or is final

      • writeDeclaredStaticField

        public static void writeDeclaredStaticField​(java.lang.Class cls,
                                            java.lang.String fieldName,
                                            java.lang.Object value)
                                     throws java.lang.IllegalAccessException
        Write 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:
        java.lang.IllegalArgumentException - if the field cannot be located or is not static
        java.lang.IllegalAccessException - if the field is not public or is final

      • writeDeclaredStaticField

        public static void writeDeclaredStaticField​(java.lang.Class cls,
                                            java.lang.String fieldName,
                                            java.lang.Object value,
                                            boolean forceAccess)
                                     throws java.lang.IllegalAccessException
        Write 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 setAccessible method. False will only match public fields.
        Throws:
        java.lang.IllegalArgumentException - if the field cannot be located or is not static
        java.lang.IllegalAccessException - if the field is not made accessible or is final

      • writeField

        public static void writeField​(java.lang.reflect.Field field,
                              java.lang.Object target,
                              java.lang.Object value)
                       throws java.lang.IllegalAccessException
        Write an accessible field.
        Parameters:
        field - to write
        target - the object to call on, may be null for static fields
        value - to set
        Throws:
        java.lang.IllegalArgumentException - if the field is null
        java.lang.IllegalAccessException - if the field is not accessible or is final

      • writeField

        public static void writeField​(java.lang.reflect.Field field,
                              java.lang.Object target,
                              java.lang.Object value,
                              boolean forceAccess)
                       throws java.lang.IllegalAccessException
        Write 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 setAccessible method. False will only match public fields.
        Throws:
        java.lang.IllegalArgumentException - if the field is null
        java.lang.IllegalAccessException - if the field is not made accessible or is final

      • writeField

        public static void writeField​(java.lang.Object target,
                              java.lang.String fieldName,
                              java.lang.Object value)
                       throws java.lang.IllegalAccessException
        Write 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:
        java.lang.IllegalArgumentException - if target or fieldName is null
        java.lang.IllegalAccessException - if the field is not accessible

      • writeField

        public static void writeField​(java.lang.Object target,
                              java.lang.String fieldName,
                              java.lang.Object value,
                              boolean forceAccess)
                       throws java.lang.IllegalAccessException
        Write 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 setAccessible method. False will only match public fields.
        Throws:
        java.lang.IllegalArgumentException - if target or fieldName is null
        java.lang.IllegalAccessException - if the field is not made accessible

      • writeDeclaredField

        public static void writeDeclaredField​(java.lang.Object target,
                                      java.lang.String fieldName,
                                      java.lang.Object value)
                               throws java.lang.IllegalAccessException
        Write 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:
        java.lang.IllegalArgumentException - if target or fieldName is null
        java.lang.IllegalAccessException - if the field is not made accessible

      • writeDeclaredField

        public static void writeDeclaredField​(java.lang.Object target,
                                      java.lang.String fieldName,
                                      java.lang.Object value,
                                      boolean forceAccess)
                               throws java.lang.IllegalAccessException
        Write 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 setAccessible method. False will only match public fields.
        Throws:
        java.lang.IllegalArgumentException - if target or fieldName is null
        java.lang.IllegalAccessException - if the field is not made accessible