Class SingleFieldBuilder<MType,BType,IType> (3.19.4)

public class SingleFieldBuilder<MType,BType,IType> implements GeneratedMessage.BuilderParent

SingleFieldBuilder implements a structure that a protocol message uses to hold a single field of another protocol message. It supports the classical use case of setting an immutable Message as the value of the field and is highly optimized around this.

It also supports the additional use case of setting a Message.Builder as the field and deferring conversion of that Builder to an immutable Message. In this way, it's possible to maintain a tree of Builder's that acts as a fully read/write data structure.
Logically, one can think of a tree of builders as converting the entire tree to messages when build is called on the root or when any method is called that desires a Message instead of a Builder. In terms of the implementation, the SingleFieldBuilder and RepeatedFieldBuilder classes cache messages that were created so that messages only need to be created when some change occurred in its builder or a builder for one of its descendants.

Inheritance

java.lang.Object > SingleFieldBuilder<MType,BType,IType>

Type Parameters

NameDescription
MType
BType
IType

Constructors

SingleFieldBuilder(MType message, GeneratedMessage.BuilderParent parent, boolean isClean)

public SingleFieldBuilder(MType message, GeneratedMessage.BuilderParent parent, boolean isClean)
Parameters
NameDescription
messageMType
parentGeneratedMessage.BuilderParent
isCleanboolean

Methods

build()

public MType build()

Builds the message and returns it.

Returns
TypeDescription
MType

the message

clear()

public SingleFieldBuilder<MType,BType,IType> clear()

Clears the value of the field.

Returns
TypeDescription
SingleFieldBuilder<MType,BType,IType>

the builder

dispose()

public void dispose()

getBuilder()

public BType getBuilder()

Gets a builder for the field. If no builder has been created yet, a builder is created on demand by calling Message#toBuilder.

Returns
TypeDescription
BType

The builder for the field

getMessage()

public MType getMessage()

Get the message for the field. If the message is currently stored as a Builder, it is converted to a Message by calling Message.Builder#buildPartial on it. If no message has been set, returns the default instance of the message.

Returns
TypeDescription
MType

the message for the field

getMessageOrBuilder()

public IType getMessageOrBuilder()

Gets the base class interface for the field. This may either be a builder or a message. It will return whatever is more efficient.

Returns
TypeDescription
IType

the message or builder for the field as the base class interface

markDirty()

public void markDirty()

A builder becomes dirty whenever a field is modified -- including fields in nested builders -- and becomes clean when build() is called. Thus, when a builder becomes dirty, all its parents become dirty as well, and when it becomes clean, all its children become clean. The dirtiness state is used to invalidate certain cached values.

To this end, a builder calls markDirty() on its parent whenever it transitions from clean to dirty. The parent must propagate this call to its own parent, unless it was already dirty, in which case the grandparent must necessarily already be dirty as well. The parent can only transition back to "clean" after calling build() on all children.

mergeFrom(MType value)

public SingleFieldBuilder<MType,BType,IType> mergeFrom(MType value)

Merges the field from another field.

Parameter
NameDescription
valueMType

the value to merge from

Returns
TypeDescription
SingleFieldBuilder<MType,BType,IType>

the builder

setMessage(MType message)

public SingleFieldBuilder<MType,BType,IType> setMessage(MType message)

Sets a message for the field replacing any existing value.

Parameter
NameDescription
messageMType

the message to set

Returns
TypeDescription
SingleFieldBuilder<MType,BType,IType>

the builder