JByteBuffer class
A byte JBuffer.
The bindings for java.nio.ByteBuffer.
This enables fast memory copying between Java and Dart when directly allocated (See JByteBuffer.allocateDirect).
To create a JByteBuffer from the content of a Uint8List, use JByteBuffer.fromList. This uses direct allocation to enable fast copying.
asUint8List provides a direct access to the underlying Uint8List that this buffer uses. This means any changes to it will change the content of the buffer and vice versa. This can be used to access to Uint8List methods such as Uint8List.setRange.
Example:
final directBuffer = JByteBuffer.allocateDirect(3);
directBuffer.asUint8List().setAll(0, [1, 2, 3]);
// The buffer is now 1, 2, 3.
Both the original buffer and the Uint8List keep the underlying Java buffer alive. Once all the instances of the original buffer and the lists produced from asUint8List are inaccessible both in Java and Dart, Java will correctly garbage collects the buffer and frees its underlying memory.
Example:
final directBuffer = JByteBuffer.allocateDirect(3);
final data = directBuffer.asUint8List();
directBuffer.release(); // Releasing the original buffer.
data.setAll(0, [1, 2, 3]); // Works! [data] is still accessible.
The original buffer can be released when calling asUint8List
by setting the releaseOriginal parameter to true.
Example:
final directBuffer = JByteBuffer.allocateDirect(3);
// [releaseOriginal] is `false` by default.
final data1 = directBuffer.asUint8List();
directBuffer.nextByte = 42; // No problem!
print(data1[0]); // prints 42!
final data2 = directBuffer.asUint8List(releaseOriginal: true);
// directBuffer.nextByte = 42; // throws [UseAfterReleaseException]!
- Inheritance
- Available extensions
Constructors
- JByteBuffer.allocate(int capacity)
-
Allocates a new byte buffer.
factory
- JByteBuffer.allocateDirect(int capacity)
-
Allocates a new direct byte buffer.
factory
- JByteBuffer.fromList(Uint8List list)
-
Creates a JByteBuffer from the content of
list.factory - JByteBuffer.fromReference(JReference reference)
Properties
- array → JByteArray
-
The array that backs this buffer.
no setteroverride
- arrayOffset → int
-
The offset within this buffer's backing array of the first element
of the buffer.
no setterinherited
- capacity → int
-
The number of elements this buffer contains.
no setterinherited
- hasArray → bool
-
Whether or not this buffer is backed by an accessible array.
no setterinherited
- hashCode → int
-
The hash code for this object.
no setterinherited
- hasRemaining → bool
-
Whether there are any elements between the current position and
the limit.
no setterinherited
- isDirect → bool
-
Whether or not this buffer is direct.
no setterinherited
- isReadOnly → bool
-
Whether or not this buffer is read-only.
no setterinherited
- isReleased → bool
-
no setterinherited
- jClass → JClass
-
Returns JClass corresponding to concrete class of this object.
no setterinherited
- limit ↔ int
-
The index of the first element that should not be read or written.
getter/setter pairinherited
- nextByte ↔ int
-
Reads the byte at this buffer's current position, and then increments
the position.
getter/setter pair
- position ↔ int
-
The index of the next element to be read or written.
getter/setter pairinherited
- remaining → int
-
The number of elements between the current position and the
limit.
no setterinherited
- runtimeType → Type
-
A representation of the runtime type of the object.
no setterinherited
Methods
-
as<
T extends JObject?> (JObjType< T> type, {bool releaseOriginal = false}) → T -
Casts this object to another
type.inherited -
asReadOnlyBuffer(
) → JByteBuffer - Creates a new, read-only byte buffer that shares this buffer's content.
-
asUint8List(
{bool releaseOriginal = false}) → Uint8List - Returns this byte buffer as a Uint8List.
-
clear(
) → void -
Clears this buffer.
inherited
-
duplicate(
) → JByteBuffer - Creates a new byte buffer that shares this buffer's content.
-
flip(
) → void -
Flips this buffer.
inherited
-
isA<
T extends JObject?> (JObjType< T> type) → bool -
Whether this object is of the given
typeignoring the type parameters.inherited -
isInstanceOf(
JClass jclass) → bool -
Whether this object is of the type of the given
jclass.inherited -
mark(
) → void -
Sets this buffer's mark at its position.
inherited
-
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a nonexistent method or property is accessed.
inherited
-
release(
) → void -
Releases the underlying
reference.inherited -
releasedBy(
Arena arena) → void -
Registers this object to be released at the end of
arena's lifetime.inherited -
reset(
) → void -
Resets this buffer's position to the previously-marked position.
inherited
-
rewind(
) → void -
Rewinds this buffer.
inherited
-
slice(
) → JByteBuffer - Creates a new byte buffer whose content is a shared subsequence of this buffer's content.
-
toString(
) → String -
A string representation of this object.
inherited
-
use<
R> (R callback(T)) → R -
Available on T, provided by the JObjectUseExtension extension
Appliescallbackon this object and then delete the underlying JNI reference, returning the result ofcallback.
Operators
-
operator ==(
Object other) → bool -
The equality operator.
inherited
Static Methods
-
wrap(
JByteArray array, [int? offset, int? length]) → JByteBuffer - Wraps a byte array into a buffer.
Constants
- nullableType → const JByteBufferNullableType
- The type which includes information such as the signature of this class.
- type → const JByteBufferType
- The type which includes information such as the signature of this class.