Java : Buffer con ejemplos

Buffer (Java SE 22 & JDK 22) en Java con ejemplos.
Encontrará muestras de código para la mayoría de los métodos Buffer.

Nota :

Este artículo puede utilizar software de traducción para su comodidad. Consulte también la versión original en inglés.

Summary

Un contenedor para datos de un tipo primitivo específico. (Traducción automática)

Class diagram

final var buffer = IntBuffer.allocate(5);

System.out.println(buffer instanceof Buffer); // true

System.out.println(buffer.capacity()); // 5
System.out.println(buffer.limit()); // 5
System.out.println(buffer.position()); // 0

buffer.put(10);
System.out.println(buffer.position()); // 1

buffer.put(20);
System.out.println(buffer.position()); // 2

buffer.put(30);
System.out.println(buffer.position()); // 3

if (buffer.hasArray()) {
    final var ret = buffer.array();
    System.out.println(Arrays.toString(ret)); // [10, 20, 30, 0, 0]
}

final byte[] array = {10, 20, 30};
final var buffer = ByteBuffer.wrap(array);

System.out.println(buffer instanceof Buffer); // true

System.out.println(buffer.capacity()); // 3
System.out.println(buffer.limit()); // 3
System.out.println(buffer.position()); // 0

System.out.println(buffer.get()); // 10
System.out.println(buffer.position()); // 1

System.out.println(buffer.get()); // 20
System.out.println(buffer.position()); // 2

System.out.println(buffer.get()); // 30
System.out.println(buffer.position()); // 3

Methods

abstract Object array ()

Devuelve la matriz que respalda este búfer (operación opcional). (Traducción automática)

final Buffer buffer = IntBuffer.allocate(5)
        .put(10)
        .put(20)
        .put(30);

if (buffer.hasArray()) {
    if (buffer.array() instanceof int[] array) {
        System.out.println(Arrays.toString(array)); // [10, 20, 30, 0, 0]
    }
}

abstract int arrayOffset ()

Devuelve el desplazamiento dentro de la matriz de respaldo de este búfer del primer elemento del búfer (operación opcional). (Traducción automática)

final byte[] bytes = {10, 20, 30, 40, 50};

final var buffer = ByteBuffer.wrap(bytes);
System.out.println(buffer instanceof Buffer); // true

final var sliced = buffer.slice(2, 3);
System.out.println(sliced instanceof Buffer); // true

System.out.println(buffer); // java.nio.HeapByteBuffer[pos=0 lim=5 cap=5]
if (buffer.hasArray()) {
    System.out.println(buffer.arrayOffset()); // 0
    System.out.println(buffer.get()); // 10
    System.out.println(buffer.get()); // 20
    System.out.println(buffer.get()); // 30
    System.out.println(buffer.get()); // 40
    System.out.println(buffer.get()); // 50
}

System.out.println(sliced); // java.nio.HeapByteBuffer[pos=0 lim=3 cap=3]
if (sliced.hasArray()) {
    System.out.println(sliced.arrayOffset()); // 2
    System.out.println(sliced.get()); // 30
    System.out.println(sliced.get()); // 40
    System.out.println(sliced.get()); // 50
}

final int capacity ()

Devuelve la capacidad de este buffer. (Traducción automática)

final Buffer buffer = ByteBuffer.allocate(100);
System.out.println(buffer.capacity()); // 100

final byte[] bytes = {10, 20, 30, 40, 50};
final Buffer buffer = ByteBuffer.wrap(bytes);

System.out.println(buffer.capacity()); // 5

Buffer clear ()

Borra este buffer. (Traducción automática)

Please see also : rewind()

final byte[] array = {10, 20, 30, 40, 50};
final var buffer = ByteBuffer.wrap(array);
System.out.println(buffer instanceof Buffer); // true

buffer.position(2);
buffer.limit(4);

System.out.println(buffer); // java.nio.HeapByteBuffer[pos=2 lim=4 cap=5]

System.out.println(buffer.get()); // 30
System.out.println(buffer.get()); // 40
System.out.println(buffer.hasRemaining()); // false

System.out.println(buffer.clear()); // java.nio.HeapByteBuffer[pos=0 lim=5 cap=5]

System.out.println(buffer.get()); // 10
System.out.println(buffer.get()); // 20
System.out.println(buffer.get()); // 30
System.out.println(buffer.get()); // 40
System.out.println(buffer.get()); // 50
System.out.println(buffer.hasRemaining()); // false

abstract Buffer duplicate ()

Crea un nuevo buffer que comparte el contenido de este buffer. (Traducción automática)

final byte[] array = {10, 20, 30, 40, 50};
final var buffer = ByteBuffer.wrap(array);
System.out.println(buffer instanceof Buffer); // true

buffer.position(1);
buffer.limit(4);

final var duplicated = buffer.duplicate();
System.out.println(duplicated instanceof Buffer); // true

System.out.println(buffer); // java.nio.HeapByteBuffer[pos=1 lim=4 cap=5]
System.out.println(duplicated); // java.nio.HeapByteBuffer[pos=1 lim=4 cap=5]

System.out.println(buffer.get()); // 20
System.out.println(buffer.get()); // 30
System.out.println(buffer.get()); // 40

System.out.println(duplicated.get()); // 20
System.out.println(duplicated.get()); // 30
System.out.println(duplicated.get()); // 40

Buffer flip ()

Voltea este buffer. (Traducción automática)

final byte[] array = {10, 20, 30, 40, 50};
final var buffer = ByteBuffer.wrap(array);
System.out.println(buffer instanceof Buffer); // true

System.out.println(buffer.get()); // 10
System.out.println(buffer.get()); // 20
System.out.println(buffer.get()); // 30

System.out.println(buffer); // java.nio.HeapByteBuffer[pos=3 lim=5 cap=5]
System.out.println(buffer.flip()); // java.nio.HeapByteBuffer[pos=0 lim=3 cap=5]

System.out.println(buffer.get()); // 10
System.out.println(buffer.get()); // 20
System.out.println(buffer.get()); // 30

abstract boolean hasArray ()

Indica si este búfer está respaldado o no por una matriz accesible. (Traducción automática)

final var buffer = IntBuffer.allocate(5)
        .put(10)
        .put(20)
        .put(30);
System.out.println(buffer instanceof Buffer); // true

final var ret = buffer.hasArray();
System.out.println(ret); // true

if (ret) {
    final var array = buffer.array();
    System.out.println(Arrays.toString(array)); // [10, 20, 30, 0, 0]
}

final var buffer = ByteBuffer.allocateDirect(5);
System.out.println(buffer instanceof Buffer); // true

System.out.println(buffer.hasArray()); // false
try {
    var _ = buffer.array();
} catch (UnsupportedOperationException e) {
    System.out.println("UnsupportedOperationException!");
}

// Result
// ↓
//UnsupportedOperationException!

final boolean hasRemaining ()

Indica si hay elementos entre la posición actual y el límite. (Traducción automática)

final byte[] array = {10, 20, 30, 40};
final var buffer = ByteBuffer.wrap(array);
System.out.println(buffer instanceof Buffer); // true

buffer.limit(3);

System.out.println(buffer); // java.nio.HeapByteBuffer[pos=0 lim=3 cap=4]
System.out.println(buffer.hasRemaining()); // true
System.out.println(buffer.remaining()); // 3

System.out.println(buffer.get()); // 10

System.out.println(buffer); // java.nio.HeapByteBuffer[pos=1 lim=3 cap=4]
System.out.println(buffer.hasRemaining()); // true
System.out.println(buffer.remaining()); // 2

System.out.println(buffer.get()); // 20

System.out.println(buffer); // java.nio.HeapByteBuffer[pos=2 lim=3 cap=4]
System.out.println(buffer.hasRemaining()); // true
System.out.println(buffer.remaining()); // 1

System.out.println(buffer.get()); // 30

System.out.println(buffer); // java.nio.HeapByteBuffer[pos=3 lim=3 cap=4]
System.out.println(buffer.hasRemaining()); // false
System.out.println(buffer.remaining()); // 0

abstract boolean isDirect ()

Indica si este búfer es directo o no. (Traducción automática)

final Buffer buffer = ByteBuffer.allocate(5);
System.out.println(buffer.isDirect()); // false

final Buffer buffer = ByteBuffer.allocateDirect(5);
System.out.println(buffer.isDirect()); // true

abstract boolean isReadOnly ()

Indica si este búfer es de solo lectura o no. (Traducción automática)

final var buffer = IntBuffer.allocate(5);
System.out.println(buffer instanceof Buffer); // true

System.out.println(buffer.isReadOnly()); // false

buffer.put(10);
buffer.put(20);
buffer.put(30);

System.out.println(buffer); // java.nio.HeapIntBuffer[pos=3 lim=5 cap=5]

final var buffer = IntBuffer.allocate(5).asReadOnlyBuffer();
System.out.println(buffer instanceof Buffer); // true

System.out.println(buffer.isReadOnly()); // true

try {
    buffer.put(10);
} catch (ReadOnlyBufferException e) {
    System.out.println("ReadOnlyBufferException!");
}

// Result
// ↓
//ReadOnlyBufferException!

final int limit ()

Devuelve el límite de este buffer. (Traducción automática)

final byte[] array = {10, 20, 30, 40, 50};
final Buffer buffer = ByteBuffer.wrap(array);

System.out.println(buffer); // java.nio.HeapByteBuffer[pos=0 lim=5 cap=5]
System.out.println(buffer.limit()); // 5

System.out.println(buffer.limit(3)); // java.nio.HeapByteBuffer[pos=0 lim=3 cap=5]
System.out.println(buffer.limit()); // 3

System.out.println(buffer.clear()); // java.nio.HeapByteBuffer[pos=0 lim=5 cap=5]
System.out.println(buffer.limit()); // 5

final byte[] array = {10, 20, 30, 40, 50};
final var buffer = ByteBuffer.wrap(array);
System.out.println(buffer instanceof Buffer); // true

System.out.println(buffer.limit(3)); // java.nio.HeapByteBuffer[pos=0 lim=3 cap=5]

System.out.println(buffer.get()); // 10
System.out.println(buffer.get()); // 20
System.out.println(buffer.get()); // 30

try {
    var _ = buffer.get();
} catch (BufferUnderflowException e) {
    System.out.println("BufferUnderflowException!");
}

// Result
// ↓
//BufferUnderflowException!

Buffer limit (int newLimit)

Establece el límite de este búfer. (Traducción automática)

final byte[] array = {10, 20, 30, 40, 50};
final Buffer buffer = ByteBuffer.wrap(array);

System.out.println(buffer); // java.nio.HeapByteBuffer[pos=0 lim=5 cap=5]
System.out.println(buffer.limit()); // 5

System.out.println(buffer.limit(3)); // java.nio.HeapByteBuffer[pos=0 lim=3 cap=5]
System.out.println(buffer.limit()); // 3

System.out.println(buffer.clear()); // java.nio.HeapByteBuffer[pos=0 lim=5 cap=5]
System.out.println(buffer.limit()); // 5

final byte[] array = {10, 20, 30, 40, 50};
final var buffer = ByteBuffer.wrap(array);
System.out.println(buffer instanceof Buffer); // true

System.out.println(buffer.limit(3)); // java.nio.HeapByteBuffer[pos=0 lim=3 cap=5]

System.out.println(buffer.get()); // 10
System.out.println(buffer.get()); // 20
System.out.println(buffer.get()); // 30

try {
    var _ = buffer.get();
} catch (BufferUnderflowException e) {
    System.out.println("BufferUnderflowException!");
}

// Result
// ↓
//BufferUnderflowException!

Buffer mark ()

Establece la marca de este búfer en su posición. (Traducción automática)

final byte[] array = {10, 20, 30, 40, 50};
final var buffer = ByteBuffer.wrap(array);
System.out.println(buffer instanceof Buffer); // true

System.out.println(buffer.get()); // 10
System.out.println(buffer.get()); // 20

System.out.println(buffer.position()); // 2
System.out.println(buffer.mark()); // java.nio.HeapByteBuffer[pos=2 lim=5 cap=5]

System.out.println(buffer.get()); // 30
System.out.println(buffer.get()); // 40
System.out.println(buffer.get()); // 50

System.out.println(buffer.position()); // 5
System.out.println(buffer.reset()); // java.nio.HeapByteBuffer[pos=2 lim=5 cap=5]

System.out.println(buffer.get()); // 30
System.out.println(buffer.get()); // 40
System.out.println(buffer.get()); // 50

final int position ()

Devuelve la posición de este buffer. (Traducción automática)

final byte[] array = {10, 20, 30, 40, 50};
final var buffer = ByteBuffer.wrap(array);
System.out.println(buffer instanceof Buffer); // true

System.out.println(buffer.position()); // 0

System.out.println(buffer.get()); // 10
System.out.println(buffer.position()); // 1

System.out.println(buffer.get()); // 20
System.out.println(buffer.position()); // 2

System.out.println(buffer.get()); // 30
System.out.println(buffer.position()); // 3

System.out.println(buffer.get()); // 40
System.out.println(buffer.position()); // 4

System.out.println(buffer.get()); // 50
System.out.println(buffer.position()); // 5

System.out.println(buffer.position(3)); // java.nio.HeapByteBuffer[pos=3 lim=5 cap=5]

System.out.println(buffer.get()); // 40
System.out.println(buffer.position()); // 4

System.out.println(buffer.get()); // 50
System.out.println(buffer.position()); // 5

Buffer position (int newPosition)

Establece la posición de este búfer. (Traducción automática)

final byte[] array = {10, 20, 30, 40, 50};
final var buffer = ByteBuffer.wrap(array);
System.out.println(buffer instanceof Buffer); // true

System.out.println(buffer.position()); // 0

System.out.println(buffer.get()); // 10
System.out.println(buffer.position()); // 1

System.out.println(buffer.get()); // 20
System.out.println(buffer.position()); // 2

System.out.println(buffer.get()); // 30
System.out.println(buffer.position()); // 3

System.out.println(buffer.get()); // 40
System.out.println(buffer.position()); // 4

System.out.println(buffer.get()); // 50
System.out.println(buffer.position()); // 5

System.out.println(buffer.position(3)); // java.nio.HeapByteBuffer[pos=3 lim=5 cap=5]

System.out.println(buffer.get()); // 40
System.out.println(buffer.position()); // 4

System.out.println(buffer.get()); // 50
System.out.println(buffer.position()); // 5

final int remaining ()

Devuelve el número de elementos entre la posición actual y el límite. (Traducción automática)

final byte[] array = {10, 20, 30, 40};
final var buffer = ByteBuffer.wrap(array);
System.out.println(buffer instanceof Buffer); // true

buffer.limit(3);

System.out.println(buffer); // java.nio.HeapByteBuffer[pos=0 lim=3 cap=4]
System.out.println(buffer.hasRemaining()); // true
System.out.println(buffer.remaining()); // 3

System.out.println(buffer.get()); // 10

System.out.println(buffer); // java.nio.HeapByteBuffer[pos=1 lim=3 cap=4]
System.out.println(buffer.hasRemaining()); // true
System.out.println(buffer.remaining()); // 2

System.out.println(buffer.get()); // 20

System.out.println(buffer); // java.nio.HeapByteBuffer[pos=2 lim=3 cap=4]
System.out.println(buffer.hasRemaining()); // true
System.out.println(buffer.remaining()); // 1

System.out.println(buffer.get()); // 30

System.out.println(buffer); // java.nio.HeapByteBuffer[pos=3 lim=3 cap=4]
System.out.println(buffer.hasRemaining()); // false
System.out.println(buffer.remaining()); // 0

Buffer reset ()

Restablece la posición de este búfer a la posición marcada previamente. (Traducción automática)

final byte[] array = {10, 20, 30, 40, 50};
final var buffer = ByteBuffer.wrap(array);
System.out.println(buffer instanceof Buffer); // true

System.out.println(buffer.get()); // 10
System.out.println(buffer.get()); // 20

System.out.println(buffer.position()); // 2
System.out.println(buffer.mark()); // java.nio.HeapByteBuffer[pos=2 lim=5 cap=5]

System.out.println(buffer.get()); // 30
System.out.println(buffer.get()); // 40
System.out.println(buffer.get()); // 50

System.out.println(buffer.position()); // 5
System.out.println(buffer.reset()); // java.nio.HeapByteBuffer[pos=2 lim=5 cap=5]

System.out.println(buffer.get()); // 30
System.out.println(buffer.get()); // 40
System.out.println(buffer.get()); // 50

Buffer rewind ()

Rebobina este búfer. (Traducción automática)

Please see also : clear()

final int[] array = {10, 20, 30, 40, 50};
final Buffer buffer = IntBuffer.wrap(array);

buffer.position(2);
buffer.limit(4);

System.out.println(buffer.position()); // 2
System.out.println(buffer.limit()); // 4

System.out.println(buffer.rewind()); // java.nio.HeapIntBuffer[pos=0 lim=4 cap=5]

System.out.println(buffer.position()); // 0
System.out.println(buffer.limit()); // 4

abstract Buffer slice ()

Crea un nuevo buffer cuyo contenido es una subsecuencia compartida del contenido de este buffer. (Traducción automática)

final byte[] array = {10, 20, 30, 40, 50};
final var buffer = ByteBuffer.wrap(array);
System.out.println(buffer instanceof Buffer); // true

buffer.position(1);
buffer.limit(4);

final var sliced = buffer.slice();
System.out.println(sliced instanceof Buffer); // true

System.out.println(buffer); // java.nio.HeapByteBuffer[pos=1 lim=4 cap=5]
System.out.println(sliced); // java.nio.HeapByteBuffer[pos=0 lim=3 cap=3]

System.out.println(buffer.get()); // 20
System.out.println(buffer.get()); // 30
System.out.println(buffer.get()); // 40
System.out.println(buffer.hasRemaining()); // false

System.out.println(sliced.get()); // 20
System.out.println(sliced.get()); // 30
System.out.println(sliced.get()); // 40
System.out.println(sliced.hasRemaining()); // false

abstract Buffer slice (int index, int length)

Crea un nuevo buffer cuyo contenido es una subsecuencia compartida del contenido de este buffer. (Traducción automática)

final byte[] array = {10, 20, 30, 40, 50};
final var buffer = ByteBuffer.wrap(array);
System.out.println(buffer instanceof Buffer); // true

final var sliced = buffer.slice(2, 3);
System.out.println(sliced instanceof Buffer); // true

System.out.println(buffer); // java.nio.HeapByteBuffer[pos=0 lim=5 cap=5]
System.out.println(sliced); // java.nio.HeapByteBuffer[pos=0 lim=3 cap=3]

System.out.println(buffer.get()); // 10
System.out.println(buffer.get()); // 20
System.out.println(buffer.get()); // 30
System.out.println(buffer.get()); // 40
System.out.println(buffer.get()); // 50
System.out.println(buffer.hasRemaining()); // false

System.out.println(sliced.get()); // 30
System.out.println(sliced.get()); // 40
System.out.println(sliced.get()); // 50
System.out.println(sliced.hasRemaining()); // false

Ejemplos de API
- Buffer

Java : Buffer con ejemplos

Summary

Methods

abstract Object array ()

abstract int arrayOffset ()

final int capacity ()

Buffer clear ()

abstract Buffer duplicate ()

Buffer flip ()

abstract boolean hasArray ()

final boolean hasRemaining ()

abstract boolean isDirect ()

abstract boolean isReadOnly ()

final int limit ()

Buffer limit (int newLimit)

Buffer mark ()

final int position ()

Buffer position (int newPosition)

final int remaining ()

Buffer reset ()

Buffer rewind ()

abstract Buffer slice ()

abstract Buffer slice (int index, int length)

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