com.facebook.presto.jdbc.internal.drift.annotations.ThriftField Maven / Gradle / Ivy
/*
* Copyright (C) 2012 Facebook, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.facebook.presto.jdbc.internal.drift.annotations;
import java.lang.annotation.Documented;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;
import static java.lang.annotation.ElementType.FIELD;
import static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.ElementType.PARAMETER;
import static java.lang.annotation.RetentionPolicy.RUNTIME;
/**
* Marks a field, method or parameter as a Thrift field.
*/
@Documented
@Retention(RUNTIME)
@Target({METHOD, FIELD, PARAMETER})
public @interface ThriftField
{
short value() default Short.MIN_VALUE;
/**
* Indicates this ThriftField has a negative ID, which is deprecated.
*/
boolean isLegacyId() default false;
String name() default "";
Requiredness requiredness() default Requiredness.UNSPECIFIED;
Recursiveness isRecursive() default Recursiveness.UNSPECIFIED;
ThriftIdlAnnotation[] idlAnnotations() default {};
enum Recursiveness
{
UNSPECIFIED,
FALSE,
TRUE,
}
/**
* 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 Requiredness
{
/**
* This is the default (unset) value for {@link ThriftField#requiredness()}. It will not
* conflict with other explicit settings of {@link #NONE}, {@link #REQUIRED}, or {@link
* #OPTIONAL}. If all of the {@link ThriftField} annotations for
* a field are left UNSPECIFIED, it will default to {@link #NONE}.
*/
UNSPECIFIED,
/**
* 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 {@link #OPTIONAL} or {@link #REQUIRED} for the same
* field.
*
* The serialization behavior is that {@code 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 {@code 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).
*/
NONE,
/**
* This behavior indicates that the field will always be serialized (and it is an error if the
* value is {@code null}), and must always be deserialized (and it is an error if a value
* is not read).
*/
REQUIRED,
/**
* This behavior indicates that it is always ok if the field is {@code null} when serializing,
* and that it is always ok to not read a value (and the field will be set to {@code null}
* when this happens). As such, primitive types should be replaced with boxed types, so that
* null is always a possibility.
*/
OPTIONAL
}
}