com.facebook.drift.annotations

Enum ThriftField.Requiredness

java.lang.Object

java.lang.Enum<ThriftField.Requiredness>

com.facebook.drift.annotations.ThriftField.Requiredness

All Implemented Interfaces:

Serializable, Comparable<ThriftField.Requiredness>

Enclosing class:

ThriftField

public static enum ThriftField.Requiredness
extends Enum<ThriftField.Requiredness>

Indicates the behavior for a field when a value is not received, or when the value of the field is not set when sending.

Enum Constant Summary

Enum Constants

Enum Constant and Description
NONE This behavior is equivalent to leaving out 'optional' and 'required' in thrift IDL syntax.
OPTIONAL This behavior indicates that it is always ok if the field is null when serializing, and that it is always ok to not read a value (and the field will be set to null when this happens).
REQUIRED This behavior indicates that the field will always be serialized (and it is an error if the value is null), and must always be deserialized (and it is an error if a value is not read).
UNSPECIFIED This is the default (unset) value for ThriftField.requiredness().

Method Summary

Modifier and Type	Method and Description
static ThriftField.Requiredness	valueOf(String name) Returns the enum constant of this type with the specified name.
static ThriftField.Requiredness[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

UNSPECIFIED

public static final ThriftField.Requiredness UNSPECIFIED

This is the default (unset) value for ThriftField.requiredness(). It will not conflict with other explicit settings of NONE, REQUIRED, or OPTIONAL. If all of the ThriftField annotations for a field are left UNSPECIFIED, it will default to NONE.

NONE

public static final ThriftField.Requiredness NONE

This behavior is equivalent to leaving out 'optional' and 'required' in thrift IDL syntax. However, despite the name, this actually does correspond to defined behavior so if this value is explicitly specified in any annotations, it will conflict with other annotations that specify either OPTIONAL or REQUIRED for the same field.

The serialization behavior is that null values will not be serialized, but if the field is non-nullable (i.e. it's type is primitive) it will be serialized, even if the field was not explicitly set.

The deserialization behavior is similar: When no value is read, the field will be set to null if the type of the field is nullable, but for primitive types the field will be left untouched (so it will hold the default value for the type).

REQUIRED

public static final ThriftField.Requiredness REQUIRED

This behavior indicates that the field will always be serialized (and it is an error if the value is null), and must always be deserialized (and it is an error if a value is not read).

OPTIONAL

public static final ThriftField.Requiredness OPTIONAL

This behavior indicates that it is always ok if the field is null when serializing, and that it is always ok to not read a value (and the field will be set to null when this happens). As such, primitive types should be replaced with boxed types, so that null is always a possibility.

Method Detail

values

public static ThriftField.Requiredness[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (ThriftField.Requiredness c : ThriftField.Requiredness.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static ThriftField.Requiredness valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null