Class that helps you build a FlatBuffer. More...

Detailed Description

Class that helps you build a FlatBuffer.

See the section "Use in Java/C#" in the main FlatBuffers documentation.

Classes
class	ByteBufferBackedInputStream
	A class that allows a user to create an InputStream from a ByteBuffer.

class	ByteBufferFactory
	An interface that provides a user of the FlatBufferBuilder class the ability to specify the method in which the internal buffer gets allocated. More...

class	HeapByteBufferFactory
	An implementation of the ByteBufferFactory interface that is used when one is not provided by the user. More...

Public Member Functions
void	addBoolean (boolean x)
	Add a `boolean` to the buffer, properly aligned, and grows the buffer (if necessary). More...

void	addByte (byte x)
	Add a `byte` to the buffer, properly aligned, and grows the buffer (if necessary). More...

void	addDouble (double x)
	Add a `double` to the buffer, properly aligned, and grows the buffer (if necessary). More...

void	addFloat (float x)
	Add a `float` to the buffer, properly aligned, and grows the buffer (if necessary). More...

void	addInt (int x)
	Add an `int` to the buffer, properly aligned, and grows the buffer (if necessary). More...

void	addLong (long x)
	Add a `long` to the buffer, properly aligned, and grows the buffer (if necessary). More...

void	addOffset (int off)
	Adds on offset, relative to where it will be written. More...

void	addShort (short x)
	Add a `short` to the buffer, properly aligned, and grows the buffer (if necessary). More...

void	clear ()
	Reset the FlatBufferBuilder by purging all data that it holds.

int	createByteVector (byte[] arr)
	Create a byte array in the buffer. More...

int	createByteVector (byte[] arr, int offset, int length)
	Create a byte array in the buffer. More...

int	createByteVector (ByteBuffer byteBuffer)
	Create a byte array in the buffer. More...

int	createSharedString (String s)
	Encode the String `s` in the buffer using UTF-8. More...

int	createString (ByteBuffer s)
	Create a string in the buffer from an already encoded UTF-8 string in a ByteBuffer. More...

int	createString (CharSequence s)
	Encode the string `s` in the buffer using UTF-8. More...

ByteBuffer	createUnintializedVector (int elem_size, int num_elems, int alignment)
	Create a new array/vector and return a ByteBuffer to be filled later. More...

int	createVectorOfTables (int[] offsets)
	Create a vector of tables. More...

ByteBuffer	dataBuffer ()
	Get the ByteBuffer representing the FlatBuffer. More...

void	finish (int root_table)
	Finalize a buffer, pointing to the given `root_table`. More...

void	finish (int root_table, String file_identifier)
	Finalize a buffer, pointing to the given `root_table`. More...

void	finishSizePrefixed (int root_table)
	Finalize a buffer, pointing to the given `root_table`, with the size prefixed. More...

void	finishSizePrefixed (int root_table, String file_identifier)
	Finalize a buffer, pointing to the given `root_table`, with the size prefixed. More...

	FlatBufferBuilder ()
	Start with a buffer of 1KiB, then grow as required.

	FlatBufferBuilder (ByteBuffer existing_bb)
	Alternative constructor allowing reuse of ByteBuffers. More...

	FlatBufferBuilder (ByteBuffer existing_bb, ByteBufferFactory bb_factory)
	Alternative constructor allowing reuse of ByteBuffers. More...

	FlatBufferBuilder (int initial_size)
	Start with a buffer of size `initial_size`, then grow as required. More...

	FlatBufferBuilder (int initial_size, ByteBufferFactory bb_factory)
	Start with a buffer of size `initial_size`, then grow as required. More...

	FlatBufferBuilder (int initial_size, ByteBufferFactory bb_factory, ByteBuffer existing_bb, Utf8 utf8)
	Start with a buffer of size `initial_size`, then grow as required. More...

FlatBufferBuilder	forceDefaults (boolean forceDefaults)
	In order to save space, fields that are set to their default value don't get serialized into the buffer. More...

FlatBufferBuilder	init (ByteBuffer existing_bb, ByteBufferFactory bb_factory)
	Alternative initializer that allows reusing this object on an existing `ByteBuffer`. More...

int	offset ()
	Offset relative to the end of the buffer. More...

void	pad (int byte_size)
	Add zero valued bytes to prepare a new entry to be added. More...

void	prep (int size, int additional_bytes)
	Prepare to write an element of `size` after `additional_bytes` have been written, e.g. More...

void	putBoolean (boolean x)
	Add a `boolean` to the buffer, backwards from the current location. More...

void	putByte (byte x)
	Add a `byte` to the buffer, backwards from the current location. More...

void	putDouble (double x)
	Add a `double` to the buffer, backwards from the current location. More...

void	putFloat (float x)
	Add a `float` to the buffer, backwards from the current location. More...

void	putInt (int x)
	Add an `int` to the buffer, backwards from the current location. More...

void	putLong (long x)
	Add a `long` to the buffer, backwards from the current location. More...

void	putShort (short x)
	Add a `short` to the buffer, backwards from the current location. More...

byte[]	sizedByteArray ()
	A utility function to copy and return the ByteBuffer data as a `byte[]`. More...

byte[]	sizedByteArray (int start, int length)
	A utility function to copy and return the ByteBuffer data from `start` to `start` + `length` as a `byte[]`. More...

InputStream	sizedInputStream ()
	A utility function to return an InputStream to the ByteBuffer data. More...

Static Public Member Functions
static boolean	isFieldPresent (Table table, int offset)
	Helper function to test if a field is present in the table. More...

Protected Member Functions
void	finish (int root_table, boolean size_prefix)
	Finalize a buffer, pointing to the given `root_table`. More...

void	finish (int root_table, String file_identifier, boolean size_prefix)
	Finalize a buffer, pointing to the given `root_table`. More...

Constructor & Destructor Documentation

◆ FlatBufferBuilder() [1/5]

com.google.flatbuffers.FlatBufferBuilder.FlatBufferBuilder	(	int	initial_size,
		ByteBufferFactory	bb_factory
	)

inline

Start with a buffer of size initial_size, then grow as required.

Parameters

initial_size	The initial size of the internal buffer to use.
bb_factory	The factory to be used for allocating the internal buffer

◆ FlatBufferBuilder() [2/5]

com.google.flatbuffers.FlatBufferBuilder.FlatBufferBuilder	(	int	initial_size,
		ByteBufferFactory	bb_factory,
		ByteBuffer	existing_bb,
		Utf8	utf8
	)

inline

Start with a buffer of size initial_size, then grow as required.

Parameters

initial_size	The initial size of the internal buffer to use.
bb_factory	The factory to be used for allocating the internal buffer
existing_bb	The byte buffer to reuse.
utf8	The Utf8 codec

◆ FlatBufferBuilder() [3/5]

com.google.flatbuffers.FlatBufferBuilder.FlatBufferBuilder ( int initial_size )

inline

Start with a buffer of size initial_size, then grow as required.

Parameters

initial_size The initial size of the internal buffer to use.

◆ FlatBufferBuilder() [4/5]

com.google.flatbuffers.FlatBufferBuilder.FlatBufferBuilder	(	ByteBuffer	existing_bb,
		ByteBufferFactory	bb_factory
	)

inline

Alternative constructor allowing reuse of ByteBuffers.

The builder can still grow the buffer as necessary. User classes should make sure to call dataBuffer() to obtain the resulting encoded message.

Parameters

existing_bb	The byte buffer to reuse.
bb_factory	The factory to be used for allocating a new internal buffer if the existing buffer needs to grow

◆ FlatBufferBuilder() [5/5]

com.google.flatbuffers.FlatBufferBuilder.FlatBufferBuilder ( ByteBuffer existing_bb )

inline

Alternative constructor allowing reuse of ByteBuffers.

The builder can still grow the buffer as necessary. User classes should make sure to call dataBuffer() to obtain the resulting encoded message.

Parameters

existing_bb The byte buffer to reuse.

Member Function Documentation

◆ addBoolean()

void com.google.flatbuffers.FlatBufferBuilder.addBoolean ( boolean x )

inline

Add a boolean to the buffer, properly aligned, and grows the buffer (if necessary).

Parameters

x	A `boolean` to put into the buffer.

◆ addByte()

void com.google.flatbuffers.FlatBufferBuilder.addByte ( byte x )

inline

Add a byte to the buffer, properly aligned, and grows the buffer (if necessary).

Parameters

x	A `byte` to put into the buffer.

◆ addDouble()

void com.google.flatbuffers.FlatBufferBuilder.addDouble ( double x )

inline

Add a double to the buffer, properly aligned, and grows the buffer (if necessary).

Parameters

x	A `double` to put into the buffer.

◆ addFloat()

void com.google.flatbuffers.FlatBufferBuilder.addFloat ( float x )

inline

Add a float to the buffer, properly aligned, and grows the buffer (if necessary).

Parameters

x	A `float` to put into the buffer.

◆ addInt()

void com.google.flatbuffers.FlatBufferBuilder.addInt ( int x )

inline

Add an int to the buffer, properly aligned, and grows the buffer (if necessary).

Parameters

x	An `int` to put into the buffer.

◆ addLong()

void com.google.flatbuffers.FlatBufferBuilder.addLong ( long x )

inline

Add a long to the buffer, properly aligned, and grows the buffer (if necessary).

Parameters

x	A `long` to put into the buffer.

◆ addOffset()

void com.google.flatbuffers.FlatBufferBuilder.addOffset ( int off )

inline

Adds on offset, relative to where it will be written.

Parameters

off	The offset to add.

◆ addShort()

void com.google.flatbuffers.FlatBufferBuilder.addShort ( short x )

inline

Add a short to the buffer, properly aligned, and grows the buffer (if necessary).

Parameters

x	A `short` to put into the buffer.

◆ createByteVector() [1/3]

int com.google.flatbuffers.FlatBufferBuilder.createByteVector ( byte[] arr )

inline

Create a byte array in the buffer.

Parameters

arr	A source array with data

Returns: The offset in the buffer where the encoded array starts.

◆ createByteVector() [2/3]

int com.google.flatbuffers.FlatBufferBuilder.createByteVector	(	byte[]	arr,
		int	offset,
		int	length
	)

inline

Create a byte array in the buffer.

Parameters

arr	a source array with data.
offset	the offset in the source array to start copying from.
length	the number of bytes to copy from the source array.

Returns: The offset in the buffer where the encoded array starts.

◆ createByteVector() [3/3]

int com.google.flatbuffers.FlatBufferBuilder.createByteVector ( ByteBuffer byteBuffer )

inline

Create a byte array in the buffer.

The source ByteBuffer position is advanced by ByteBuffer#remaining() places after this call.

Parameters

byteBuffer A source ByteBuffer with data.

Returns: The offset in the buffer where the encoded array starts.

◆ createSharedString()

int com.google.flatbuffers.FlatBufferBuilder.createSharedString ( String s )

inline

Encode the String s in the buffer using UTF-8.

If a String with this exact contents has already been serialized using this method, instead simply returns the offset of the existing String.

Usage of the method will incur into additional allocations, so it is advisable to use it only when it is known upfront that your message will have several repeated strings.

Parameters

s	The String to encode.

Returns: The offset in the buffer where the encoded String starts.

◆ createString() [1/2]

int com.google.flatbuffers.FlatBufferBuilder.createString ( ByteBuffer s )

inline

Create a string in the buffer from an already encoded UTF-8 string in a ByteBuffer.

Parameters

s	An already encoded UTF-8 string as a `ByteBuffer`.

Returns: The offset in the buffer where the encoded string starts.

◆ createString() [2/2]

int com.google.flatbuffers.FlatBufferBuilder.createString ( CharSequence s )

inline

Encode the string s in the buffer using UTF-8.

If

s

is already a CharBuffer, this method is allocation free.

Parameters

s	The string to encode.

Returns: The offset in the buffer where the encoded string starts.

◆ createUnintializedVector()

ByteBuffer com.google.flatbuffers.FlatBufferBuilder.createUnintializedVector	(	int	elem_size,
		int	num_elems,
		int	alignment
	)

inline

Create a new array/vector and return a ByteBuffer to be filled later.

Call endVector after this method to get an offset to the beginning of vector.

Parameters

elem_size	the size of each element in bytes.
num_elems	number of elements in the vector.
alignment	byte alignment.

Returns: ByteBuffer with position and limit set to the space allocated for the array.

◆ createVectorOfTables()

int com.google.flatbuffers.FlatBufferBuilder.createVectorOfTables ( int[] offsets )

inline

Create a vector of tables.

Parameters

offsets Offsets of the tables.

Returns: Returns offset of the vector.

◆ dataBuffer()

ByteBuffer com.google.flatbuffers.FlatBufferBuilder.dataBuffer ( )

inline

Get the ByteBuffer representing the FlatBuffer.

Only call this after you've called finish(). The actual data starts at the ByteBuffer's current position, not necessarily at 0.

Returns: The ByteBuffer representing the FlatBuffer

◆ finish() [1/4]

void com.google.flatbuffers.FlatBufferBuilder.finish ( int root_table )

inline

Finalize a buffer, pointing to the given root_table.

Parameters

root_table An offset to be added to the buffer.

◆ finish() [2/4]

void com.google.flatbuffers.FlatBufferBuilder.finish	(	int	root_table,
		boolean	size_prefix
	)

inlineprotected

Finalize a buffer, pointing to the given root_table.

Parameters

root_table	An offset to be added to the buffer.
size_prefix	Whether to prefix the size to the buffer.

◆ finish() [3/4]

void com.google.flatbuffers.FlatBufferBuilder.finish	(	int	root_table,
		String	file_identifier
	)

inline

Finalize a buffer, pointing to the given root_table.

Parameters

root_table	An offset to be added to the buffer.
file_identifier	A FlatBuffer file identifier to be added to the buffer before `root_table`.

◆ finish() [4/4]

void com.google.flatbuffers.FlatBufferBuilder.finish	(	int	root_table,
		String	file_identifier,
		boolean	size_prefix
	)

inlineprotected

Finalize a buffer, pointing to the given root_table.

Parameters

root_table	An offset to be added to the buffer.
file_identifier	A FlatBuffer file identifier to be added to the buffer before `root_table`.
size_prefix	Whether to prefix the size to the buffer.

◆ finishSizePrefixed() [1/2]

void com.google.flatbuffers.FlatBufferBuilder.finishSizePrefixed ( int root_table )

inline

Finalize a buffer, pointing to the given root_table, with the size prefixed.

Parameters

root_table An offset to be added to the buffer.

◆ finishSizePrefixed() [2/2]

void com.google.flatbuffers.FlatBufferBuilder.finishSizePrefixed	(	int	root_table,
		String	file_identifier
	)

inline

Finalize a buffer, pointing to the given root_table, with the size prefixed.

Parameters

root_table	An offset to be added to the buffer.
file_identifier	A FlatBuffer file identifier to be added to the buffer before `root_table`.

◆ forceDefaults()

FlatBufferBuilder com.google.flatbuffers.FlatBufferBuilder.forceDefaults ( boolean forceDefaults )

inline

In order to save space, fields that are set to their default value don't get serialized into the buffer.

Forcing defaults provides a way to manually disable this optimization.

Parameters

forceDefaults When set to true, always serializes default values.

Returns: Returns this.

◆ init()

FlatBufferBuilder com.google.flatbuffers.FlatBufferBuilder.init	(	ByteBuffer	existing_bb,
		ByteBufferFactory	bb_factory
	)

inline

Alternative initializer that allows reusing this object on an existing ByteBuffer.

This method resets the builder's internal state, but keeps objects that have been allocated for temporary storage.

Parameters

existing_bb	The byte buffer to reuse.
bb_factory	The factory to be used for allocating a new internal buffer if the existing buffer needs to grow

Returns: Returns this.

◆ isFieldPresent()

static boolean com.google.flatbuffers.FlatBufferBuilder.isFieldPresent	(	Table	table,
		int	offset
	)

inlinestatic

Helper function to test if a field is present in the table.

Parameters

table	Flatbuffer table
offset	virtual table offset

Returns: true if the filed is present

◆ offset()

int com.google.flatbuffers.FlatBufferBuilder.offset ( )

inline

Offset relative to the end of the buffer.

Returns: Offset relative to the end of the buffer.

◆ pad()

void com.google.flatbuffers.FlatBufferBuilder.pad ( int byte_size )

inline

Add zero valued bytes to prepare a new entry to be added.

Parameters

byte_size Number of bytes to add.

◆ prep()

void com.google.flatbuffers.FlatBufferBuilder.prep	(	int	size,
		int	additional_bytes
	)

inline

Prepare to write an element of size after additional_bytes have been written, e.g.

if you write a string, you need to align such the int length field is aligned to com.google.flatbuffers.Constants#SIZEOF_INT, and the string data follows it directly. If all you need to do is alignment, additional_bytes will be 0.

Parameters

size	This is the of the new element to write.
additional_bytes	The padding size.

◆ putBoolean()

void com.google.flatbuffers.FlatBufferBuilder.putBoolean ( boolean x )

inline

Add a boolean to the buffer, backwards from the current location.

Doesn't align nor check for space.

Parameters

x	A `boolean` to put into the buffer.

◆ putByte()

void com.google.flatbuffers.FlatBufferBuilder.putByte ( byte x )

inline

Add a byte to the buffer, backwards from the current location.

Doesn't align nor check for space.

Parameters

x	A `byte` to put into the buffer.

◆ putDouble()

void com.google.flatbuffers.FlatBufferBuilder.putDouble ( double x )

inline

Add a double to the buffer, backwards from the current location.

Doesn't align nor check for space.

Parameters

x	A `double` to put into the buffer.

◆ putFloat()

void com.google.flatbuffers.FlatBufferBuilder.putFloat ( float x )

inline

Add a float to the buffer, backwards from the current location.

Doesn't align nor check for space.

Parameters

x	A `float` to put into the buffer.

◆ putInt()

void com.google.flatbuffers.FlatBufferBuilder.putInt ( int x )

inline

Add an int to the buffer, backwards from the current location.

Doesn't align nor check for space.

Parameters

x	An `int` to put into the buffer.

◆ putLong()

void com.google.flatbuffers.FlatBufferBuilder.putLong ( long x )

inline

Add a long to the buffer, backwards from the current location.

Doesn't align nor check for space.

Parameters

x	A `long` to put into the buffer.

◆ putShort()

void com.google.flatbuffers.FlatBufferBuilder.putShort ( short x )

inline

Add a short to the buffer, backwards from the current location.

Doesn't align nor check for space.

Parameters

x	A `short` to put into the buffer.

◆ sizedByteArray() [1/2]

byte [] com.google.flatbuffers.FlatBufferBuilder.sizedByteArray ( )

inline

A utility function to copy and return the ByteBuffer data as a byte[].

Returns: A full copy of the data buffer.

◆ sizedByteArray() [2/2]

byte [] com.google.flatbuffers.FlatBufferBuilder.sizedByteArray	(	int	start,
		int	length
	)

inline

A utility function to copy and return the ByteBuffer data from start to start + length as a byte[].

Parameters

start	Start copying at this offset.
length	How many bytes to copy.

Returns: A range copy of the data buffer.

Exceptions

IndexOutOfBoundsException If the range of bytes is ouf of bound.

◆ sizedInputStream()

InputStream com.google.flatbuffers.FlatBufferBuilder.sizedInputStream ( )

inline

A utility function to return an InputStream to the ByteBuffer data.

Returns: An InputStream that starts at the beginning of the ByteBuffer data and can read to the end of it.

The documentation for this class was generated from the following file:

FlatBufferBuilder.java

Detailed Description

Classes

Public Member Functions

Static Public Member Functions

Protected Member Functions

Constructor & Destructor Documentation

◆ FlatBufferBuilder() [1/5]

◆ FlatBufferBuilder() [2/5]

◆ FlatBufferBuilder() [3/5]

◆ FlatBufferBuilder() [4/5]

◆ FlatBufferBuilder() [5/5]

Member Function Documentation

◆ addBoolean()

◆ addByte()

◆ addDouble()

◆ addFloat()

◆ addInt()

◆ addLong()

◆ addOffset()

◆ addShort()

◆ createByteVector() [1/3]

◆ createByteVector() [2/3]

◆ createByteVector() [3/3]

◆ createSharedString()

◆ createString() [1/2]

◆ createString() [2/2]

◆ createUnintializedVector()

◆ createVectorOfTables()

◆ dataBuffer()

◆ finish() [1/4]

◆ finish() [2/4]

◆ finish() [3/4]

◆ finish() [4/4]

◆ finishSizePrefixed() [1/2]

◆ finishSizePrefixed() [2/2]

◆ forceDefaults()

◆ init()

◆ isFieldPresent()

◆ offset()

◆ pad()

◆ prep()

◆ putBoolean()

◆ putByte()

◆ putDouble()

◆ putFloat()

◆ putInt()

◆ putLong()

◆ putShort()

◆ sizedByteArray() [1/2]

◆ sizedByteArray() [2/2]

◆ sizedInputStream()