The underlying field's value is obtained as follows:

If the underlying field is a static field, the obj argument is ignored; it may be null.

Otherwise, the underlying field is an instance field. If the specified obj argument is null, the method throws a NullPointerException. If the specified object is not an instance of the class or interface declaring the underlying field, the method throws an IllegalArgumentException.

If this Field object enforces Java language access control, and the underlying field is inaccessible, the method throws an IllegalAccessException. If the underlying field is static, the class that declared the field is initialized if it has not already been initialized.

Otherwise, the value is retrieved from the underlying instance or static field. If the field has a primitive type, the value is wrapped in an object before being returned, otherwise it is returned as is.

If the field is hidden in the type of obj, the field's value is obtained according to the preceding rules.

obj	object from which the represented field's value is to be extracted
return	the value of the represented field in object obj; primitive values are wrapped in an appropriate object before being returned
Throws	IllegalAccessException: if the underlying field is inaccessible.
Throws	IllegalArgumentException: if the specified object is not an instance of the class or interface declaring the underlying field (or a subclass or implementor thereof).
Throws	NullPointerException: if the specified object is null and the field is an instance field.
Throws	ExceptionInInitializerError: if the initialization provoked by this method fails.

The operation proceeds as follows:

If the underlying field is static, the obj argument is ignored; it may be null.

Otherwise the underlying field is an instance field. If the specified object argument is null, the method throws a NullPointerException. If the specified object argument is not an instance of the class or interface declaring the underlying field, the method throws an IllegalArgumentException.

If this Field object enforces Java language access control, and the underlying field is inaccessible, the method throws an IllegalAccessException.

If the underlying field is final, the method throws an IllegalAccessException unless setAccessible(true) has succeeded for this field and this field is non-static. Setting a final field in this way is meaningful only during deserialization or reconstruction of instances of classes with blank final fields, before they are made available for access by other parts of a program. Use in any other context may have unpredictable effects, including cases in which other parts of a program continue to use the original value of this field.

If the underlying field is of a primitive type, an unwrapping conversion is attempted to convert the new value to a value of a primitive type. If this attempt fails, the method throws an IllegalArgumentException.

If, after possible unwrapping, the new value cannot be converted to the type of the underlying field by an identity or widening conversion, the method throws an IllegalArgumentException.

If the underlying field is static, the class that declared the field is initialized if it has not already been initialized.

The field is set to the possibly unwrapped and widened new value.

If the field is hidden in the type of obj, the field's value is set according to the preceding rules.

obj	the object whose field should be modified
value	the new value for the field of obj being modified
Throws	IllegalAccessException: if the underlying field is inaccessible.
Throws	IllegalArgumentException: if the specified object is not an instance of the class or interface declaring the underlying field (or a subclass or implementor thereof), or if an unwrapping conversion fails.
Throws	NullPointerException: if the specified object is null and the field is an instance field.
Throws	ExceptionInInitializerError: if the initialization provoked by this method fails.

The modifiers are placed in canonical order as specified by "The Java Language Specification". This is public, protected or private first, and then other modifiers in the following order: static, final, transient, volatile.

return	a string describing this Field, including its generic type
since	1.5

    public static final int java.lang.Thread.MIN_PRIORITY
    private int java.io.FileDescriptor.fd
 

The modifiers are placed in canonical order as specified by "The Java Language Specification". This is public, protected or private first, and then other modifiers in the following order: static, final, transient, volatile.

If the Type is a parameterized type, the Type object returned must accurately reflect the actual type parameters used in the source code.

If the type of the underlying field is a type variable or a parameterized type, it is created. Otherwise, it is resolved.

return	a Type object that represents the declared type for the field represented by this Field object
Throws	GenericSignatureFormatError: if the generic field signature does not conform to the format specified in the Java Virtual Machine Specification, 3rd edition
Throws	TypeNotPresentException: if the generic type signature of the underlying field refers to a non-existent type declaration
Throws	MalformedParameterizedTypeException: if the generic signature of the underlying field refers to a parameterized type that cannot be instantiated for any reason
since	1.5