Java : IntBuffer - API使用例

IntBuffer (Java SE 22 & JDK 22) の使い方まとめです。
ほとんどのメソッドにサンプルコードがあります。
APIドキュメントのおともにどうぞ。

概要

intバッファです。

クラス構成

IntBuffer クラスは、プリミティブ型の int を扱う Buffer の実装です。

配列と違い、

容量(capacity) : バッファのサイズ。配列の length に相当
リミット(limit) : どの位置まで読み書き可能にするか
位置(position) : 次に読み書きする位置

という３つのプロパティを持ちます。

final var buffer = IntBuffer.allocate(5);

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

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

メソッド

static IntBuffer allocate (int capacity)

新しいintバッファを割り当てます。

final var buffer = IntBuffer.allocate(5);

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

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

final int[] array ()

このバッファを補助するint配列を返します (オプションの操作)。

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

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

final int arrayOffset ()

このバッファの補助配列内にある、このバッファの最初の要素のオフセットを返します (オプションの操作)。

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

final var sliced = buffer.slice(2, 3);

System.out.println(buffer); // java.nio.HeapIntBuffer[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.HeapIntBuffer[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
}

abstract IntBuffer asReadOnlyBuffer ()

このバッファの内容を共有する新しい読込み専用intバッファを作成します。

final var buffer = IntBuffer.allocate(3);
buffer.put(10);

final var readOnlyBuffer = buffer.asReadOnlyBuffer();

System.out.println(buffer); // java.nio.HeapIntBuffer[pos=1 lim=3 cap=3]
System.out.println(readOnlyBuffer); // java.nio.HeapIntBufferR[pos=1 lim=3 cap=3]

readOnlyBuffer.clear();
System.out.println(readOnlyBuffer.get()); // 10
System.out.println(readOnlyBuffer.get()); // 0
System.out.println(readOnlyBuffer.get()); // 0

buffer.put(20);

readOnlyBuffer.clear();
System.out.println(readOnlyBuffer.get()); // 10
System.out.println(readOnlyBuffer.get()); // 20
System.out.println(readOnlyBuffer.get()); // 0

try {
    var _ = readOnlyBuffer.put(30);
} catch (ReadOnlyBufferException e) {
    System.out.println("ReadOnlyBufferException!");
}

// 結果
// ↓
//ReadOnlyBufferException!

final IntBuffer clear ()

このバッファをクリアします。

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

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

System.out.println(buffer); // java.nio.HeapIntBuffer[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.HeapIntBuffer[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 IntBuffer compact ()

このバッファを圧縮します (オプションの操作)。

final int[] array = {10, 20, 30, 40, 50, 60};
final var buffer = IntBuffer.wrap(array);

buffer.position(3);
System.out.println(buffer.compact()); // java.nio.HeapIntBuffer[pos=3 lim=6 cap=6]

System.out.println(Arrays.toString(array)); // [40, 50, 60, 40, 50, 60]

final int[] array = {10, 20, 30, 40, 50, 60};
final var buffer = IntBuffer.wrap(array);

buffer.position(2);
System.out.println(buffer.compact()); // java.nio.HeapIntBuffer[pos=4 lim=6 cap=6]

System.out.println(Arrays.toString(array)); // [30, 40, 50, 60, 50, 60]

final int[] array = {10, 20, 30, 40, 50, 60};
final var buffer = IntBuffer.wrap(array);

buffer.position(4);
System.out.println(buffer.compact()); // java.nio.HeapIntBuffer[pos=2 lim=6 cap=6]

System.out.println(Arrays.toString(array)); // [50, 60, 30, 40, 50, 60]

int compareTo (IntBuffer that)

このバッファを別のバッファと比較します。

final var buffer1 = IntBuffer.allocate(3)
        .put(10)
        .put(20)
        .put(30);

final var buffer2 = IntBuffer.allocate(3)
        .put(10)
        .put(20)
        .put(30);

buffer1.clear();
buffer2.clear();

System.out.println(buffer1.compareTo(buffer2)); // 0

final var buffer1 = IntBuffer.allocate(3)
        .put(10)
        .put(20)
        .put(30);

final var buffer2 = IntBuffer.allocate(3)
        .put(5)
        .put(50)
        .put(500);

final var buffer3 = IntBuffer.allocate(3)
        .put(30)
        .put(20)
        .put(10);

buffer1.clear();
buffer2.clear();
buffer3.clear();

System.out.println(buffer1.compareTo(buffer2)); // 1
System.out.println(buffer1.compareTo(buffer3)); // -1

abstract IntBuffer duplicate ()

このバッファの内容を共有する新しいintバッファを作成します。

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

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

final var duplicated = buffer.duplicate();

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

boolean equals (Object ob)

このバッファが別のオブジェクトと等価であるかどうかを判断します。

final var buffer1 = IntBuffer.allocate(3)
        .put(10)
        .put(20)
        .put(30);

final var buffer2 = IntBuffer.allocate(3)
        .put(10)
        .put(20)
        .put(30);

buffer1.clear();
buffer2.clear();

System.out.println(buffer1.equals(buffer2)); // true

final var buffer1 = IntBuffer.allocate(3)
        .put(10)
        .put(20)
        .put(30);

final var buffer2 = IntBuffer.allocate(3)
        .put(5)
        .put(50)
        .put(500);

final var buffer3 = IntBuffer.allocate(3)
        .put(30)
        .put(20)
        .put(10);

buffer1.clear();
buffer2.clear();
buffer3.clear();

System.out.println(buffer1.equals(buffer2)); // false
System.out.println(buffer1.equals(buffer3)); // false

final IntBuffer flip ()

このバッファをフリップ(反転)します。

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

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

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

相対getメソッドです。

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

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

abstract int get (int index)

絶対getメソッドです。

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

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

System.out.println(buffer.get(0)); // 10
System.out.println(buffer.get(1)); // 20
System.out.println(buffer.get(2)); // 30
System.out.println(buffer.get(3)); // 40
System.out.println(buffer.get(4)); // 50

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

IntBuffer get (int[] dst)

相対一括getメソッドです。

final int[] array = {10, 20, 30, 40, 50, 60, 70};
final var buffer = IntBuffer.wrap(array);

System.out.println(buffer.capacity()); // 7
System.out.println(buffer.position()); // 0

{
    final var dst = new int[3];
    System.out.println(Arrays.toString(dst)); // [0, 0, 0]

    final var ret = buffer.get(dst);
    System.out.println(ret); // java.nio.HeapIntBuffer[pos=3 lim=7 cap=7]

    System.out.println(Arrays.toString(dst)); // [10, 20, 30]
    System.out.println(buffer.position()); // 3
}
{
    final var dst = new int[3];
    System.out.println(Arrays.toString(dst)); // [0, 0, 0]

    final var ret = buffer.get(dst);
    System.out.println(ret); // java.nio.HeapIntBuffer[pos=6 lim=7 cap=7]

    System.out.println(Arrays.toString(dst)); // [40, 50, 60]
    System.out.println(buffer.position()); // 6
}

try {
    final var dst = new int[3];
    var _ = buffer.get(dst);
} catch (BufferUnderflowException e) {
    System.out.println("BufferUnderflowException!");
}

// 結果
// ↓
//BufferUnderflowException!

IntBuffer get (int[] dst, int offset, int length)

相対一括getメソッドです。

final int[] array = {10, 20, 30, 40, 50, 60, 70, 80};
final var buffer = IntBuffer.wrap(array);

System.out.println(buffer.capacity()); // 8
System.out.println(buffer.position()); // 0

{
    final var dst = new int[5];
    System.out.println(Arrays.toString(dst)); // [0, 0, 0, 0, 0]

    final var ret = buffer.get(dst, 0, 3);
    System.out.println(ret); // java.nio.HeapIntBuffer[pos=3 lim=8 cap=8]

    System.out.println(Arrays.toString(dst)); // [10, 20, 30, 0, 0]
    System.out.println(buffer.position()); // 3
}
{
    final var dst = new int[5];
    System.out.println(Arrays.toString(dst)); // [0, 0, 0, 0, 0]

    final var ret = buffer.get(dst, 1, 3);
    System.out.println(ret); // java.nio.HeapIntBuffer[pos=6 lim=8 cap=8]

    System.out.println(Arrays.toString(dst)); // [0, 40, 50, 60, 0]
    System.out.println(buffer.position()); // 6
}
{
    final var dst = new int[5];
    System.out.println(Arrays.toString(dst)); // [0, 0, 0, 0, 0]

    final var ret = buffer.get(dst, 3, 2);
    System.out.println(ret); // java.nio.HeapIntBuffer[pos=8 lim=8 cap=8]

    System.out.println(Arrays.toString(dst)); // [0, 0, 0, 70, 80]
    System.out.println(buffer.position()); // 8
}

IntBuffer get (int index, int[] dst)

絶対一括getメソッド。

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

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

{
    final var dst = new int[3];
    System.out.println(Arrays.toString(dst)); // [0, 0, 0]

    final var ret = buffer.get(0, dst);
    System.out.println(ret); // java.nio.HeapIntBuffer[pos=0 lim=5 cap=5]

    System.out.println(Arrays.toString(dst)); // [10, 20, 30]
    System.out.println(buffer.position()); // 0
}
{
    final var dst = new int[3];
    System.out.println(Arrays.toString(dst)); // [0, 0, 0]

    final var ret = buffer.get(1, dst);
    System.out.println(ret); // java.nio.HeapIntBuffer[pos=0 lim=5 cap=5]

    System.out.println(Arrays.toString(dst)); // [20, 30, 40]
    System.out.println(buffer.position()); // 0
}
{
    final var dst = new int[3];
    System.out.println(Arrays.toString(dst)); // [0, 0, 0]

    final var ret = buffer.get(2, dst);
    System.out.println(ret); // java.nio.HeapIntBuffer[pos=0 lim=5 cap=5]

    System.out.println(Arrays.toString(dst)); // [30, 40, 50]
    System.out.println(buffer.position()); // 0
}

IntBuffer get (int index, int[] dst, int offset, int length)

絶対一括getメソッド。

final int[] array = {10, 20, 30, 40, 50, 60};
final var buffer = IntBuffer.wrap(array);

System.out.println(buffer.capacity()); // 6
System.out.println(buffer.position()); // 0

{
    final var dst = new int[5];
    System.out.println(Arrays.toString(dst)); // [0, 0, 0, 0, 0]

    final var ret = buffer.get(0, dst, 0, 3);
    System.out.println(ret); // java.nio.HeapIntBuffer[pos=0 lim=6 cap=6]

    System.out.println(Arrays.toString(dst)); // [10, 20, 30, 0, 0]
    System.out.println(buffer.position()); // 0
}
{
    final var dst = new int[5];
    System.out.println(Arrays.toString(dst)); // [0, 0, 0, 0, 0]

    final var ret = buffer.get(2, dst, 1, 3);
    System.out.println(ret); // java.nio.HeapIntBuffer[pos=0 lim=6 cap=6]

    System.out.println(Arrays.toString(dst)); // [0, 30, 40, 50, 0]
    System.out.println(buffer.position()); // 0
}
{
    final var dst = new int[5];
    System.out.println(Arrays.toString(dst)); // [0, 0, 0, 0, 0]

    final var ret = buffer.get(4, dst, 3, 2);
    System.out.println(ret); // java.nio.HeapIntBuffer[pos=0 lim=6 cap=6]

    System.out.println(Arrays.toString(dst)); // [0, 0, 0, 50, 60]
    System.out.println(buffer.position()); // 0
}

final boolean hasArray ()

このバッファがアクセス可能なint配列に連動するかどうかを判断します。

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

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 = IntBuffer.allocate(5)
        .put(10)
        .put(20)
        .put(30)
        .asReadOnlyBuffer();

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

// 結果
// ↓
//UnsupportedOperationException!

int hashCode ()

このバッファの現在のハッシュ・コードを返します。

final var buffer = IntBuffer.allocate(0);
System.out.println(buffer.hashCode()); // 1

final var buffer = IntBuffer.allocate(3)
        .put(10)
        .put(20)
        .put(30)
        .clear();

System.out.println(buffer.hashCode()); // 59251

final var buffer = IntBuffer.allocate(3)
        .put(-10)
        .put(-20)
        .put(-30)
        .clear();

System.out.println(buffer.hashCode()); // 331

abstract boolean isDirect ()

現在のintバッファがダイレクト・バッファであるかどうかを判断します。

final var buffer = IntBuffer.allocate(5);
System.out.println(buffer.isDirect()); // false

final int[] array = {10, 20, 30};
final var buffer = IntBuffer.wrap(array);
System.out.println(buffer.isDirect()); // false

final var buffer = ByteBuffer.allocateDirect(12).asIntBuffer();
System.out.println(buffer.isDirect()); // true

final IntBuffer limit (int newLimit)

このバッファのリミットを設定します。

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

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

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

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

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

System.out.println(buffer.limit(3)); // java.nio.HeapIntBuffer[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!");
}

// 結果
// ↓
//BufferUnderflowException!

final IntBuffer mark ()

このバッファの現在位置にマークを設定します。

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

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.HeapIntBuffer[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.HeapIntBuffer[pos=2 lim=5 cap=5]

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

int mismatch (IntBuffer that)

このバッファと指定されたバッファの最初の不一致の相対索引を検索して戻します。

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

{
    final int[] a = {10};
    final var that = IntBuffer.wrap(a);

    System.out.println(buffer.mismatch(that)); // 1
}
{
    final int[] a = {10, 20};
    final var that = IntBuffer.wrap(a);

    System.out.println(buffer.mismatch(that)); // 2
}
{
    final int[] a = {10, 20, 30};
    final var that = IntBuffer.wrap(a);

    System.out.println(buffer.mismatch(that)); // 3
}
{
    final int[] a = {10, 20, 30, 40};
    final var that = IntBuffer.wrap(a);

    System.out.println(buffer.mismatch(that)); // -1
}
{
    final int[] a = {10, 20, 30, 40, 50};
    final var that = IntBuffer.wrap(a);

    System.out.println(buffer.mismatch(that)); // 4
}
{
    final int[] a = {10, 20, 999};
    final var that = IntBuffer.wrap(a); // 2

    System.out.println(buffer.mismatch(that));
}
{
    final int[] a = {-90, -80};
    final var that = IntBuffer.wrap(a);

    System.out.println(buffer.mismatch(that)); // 0
}

abstract ByteOrder order ()

このバッファのbyte順序を取得します。

final var os = System.getProperty("os.name");
System.out.println(os); // Windows 10

final var buffer = IntBuffer.allocate(5);
System.out.println(buffer.order()); // LITTLE_ENDIAN

final IntBuffer position (int newPosition)

このバッファの位置を設定します。

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

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.HeapIntBuffer[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

abstract IntBuffer put (int i)

相対putメソッドです (オプションの操作)。

final var buffer = IntBuffer.allocate(5);

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

System.out.println(buffer.put(10)); // java.nio.HeapIntBuffer[pos=1 lim=5 cap=5]
System.out.println(buffer.put(20)); // java.nio.HeapIntBuffer[pos=2 lim=5 cap=5]
System.out.println(buffer.put(30)); // java.nio.HeapIntBuffer[pos=3 lim=5 cap=5]
System.out.println(buffer.put(40)); // java.nio.HeapIntBuffer[pos=4 lim=5 cap=5]
System.out.println(buffer.put(50)); // java.nio.HeapIntBuffer[pos=5 lim=5 cap=5]

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

if (buffer.hasArray()) {
    final var array = buffer.array();
    System.out.println(Arrays.toString(array)); // [10, 20, 30, 40, 50]
}

final IntBuffer put (int[] src)

相対一括putメソッドです (オプションの操作)。

final var buffer = IntBuffer.allocate(6);

System.out.println(buffer.capacity()); // 6
System.out.println(buffer.position()); // 0

{
    final int[] src = {10};

    final var ret = buffer.put(src);
    System.out.println(ret); // java.nio.HeapIntBuffer[pos=1 lim=6 cap=6]
}
{
    final int[] src = {20, 30};

    final var ret = buffer.put(src);
    System.out.println(ret); // java.nio.HeapIntBuffer[pos=3 lim=6 cap=6]
}
{
    final int[] src = {40, 50, 60};

    final var ret = buffer.put(src);
    System.out.println(ret); // java.nio.HeapIntBuffer[pos=6 lim=6 cap=6]
}

System.out.println(buffer.position()); // 6

if (buffer.hasArray()) {
    final var array = buffer.array();
    System.out.println(Arrays.toString(array)); // [10, 20, 30, 40, 50, 60]
}

IntBuffer put (int[] src, int offset, int length)

相対一括putメソッドです (オプションの操作)。

final var array = new int[6];
final var buffer = IntBuffer.wrap(array);

System.out.println(buffer.capacity()); // 6
System.out.println(buffer.position()); // 0

final int[] src = {10, 20, 30, 40, 50, 60};

final var ret1 = buffer.put(src, 0, 1);
System.out.println(ret1); // java.nio.HeapIntBuffer[pos=1 lim=6 cap=6]
System.out.println(Arrays.toString(array)); // [10, 0, 0, 0, 0, 0]

final var ret2 = buffer.put(src, 1, 2);
System.out.println(ret2); // java.nio.HeapIntBuffer[pos=3 lim=6 cap=6]
System.out.println(Arrays.toString(array)); // [10, 20, 30, 0, 0, 0]

final var ret3 = buffer.put(src, 3, 3);
System.out.println(ret3); // java.nio.HeapIntBuffer[pos=6 lim=6 cap=6]
System.out.println(Arrays.toString(array)); // [10, 20, 30, 40, 50, 60]

System.out.println(buffer.position()); // 6

abstract IntBuffer put (int index, int i)

絶対putメソッドです (オプションの操作)。

final var buffer = IntBuffer.allocate(5);

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

System.out.println(buffer.put(0, 10)); // java.nio.HeapIntBuffer[pos=0 lim=5 cap=5]
System.out.println(buffer.put(1, 20)); // java.nio.HeapIntBuffer[pos=0 lim=5 cap=5]
System.out.println(buffer.put(2, 30)); // java.nio.HeapIntBuffer[pos=0 lim=5 cap=5]
System.out.println(buffer.put(3, 40)); // java.nio.HeapIntBuffer[pos=0 lim=5 cap=5]
System.out.println(buffer.put(4, 50)); // java.nio.HeapIntBuffer[pos=0 lim=5 cap=5]

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

if (buffer.hasArray()) {
    final var array = buffer.array();
    System.out.println(Arrays.toString(array)); // [10, 20, 30, 40, 50]
}

IntBuffer put (int index, int[] src)

(optional operation)の絶対一括putメソッド。

final var buffer = IntBuffer.allocate(6);

System.out.println(buffer.capacity()); // 6
System.out.println(buffer.position()); // 0

{
    final int[] src = {10};

    final var ret = buffer.put(0, src);
    System.out.println(ret); // java.nio.HeapIntBuffer[pos=0 lim=6 cap=6]
}
{
    final int[] src = {20, 30};

    final var ret = buffer.put(1, src);
    System.out.println(ret); // java.nio.HeapIntBuffer[pos=0 lim=6 cap=6]
}
{
    final int[] src = {40, 50, 60};

    final var ret = buffer.put(3, src);
    System.out.println(ret); // java.nio.HeapIntBuffer[pos=0 lim=6 cap=6]
}

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

if (buffer.hasArray()) {
    final var array = buffer.array();
    System.out.println(Arrays.toString(array)); // [10, 20, 30, 40, 50, 60]
}

IntBuffer put (int index, int[] src, int offset, int length)

(optional operation)の絶対一括putメソッド。

final var array = new int[6];
final var buffer = IntBuffer.wrap(array);

System.out.println(buffer.capacity()); // 6
System.out.println(buffer.position()); // 0

final int[] src = {10, 20, 30, 40, 50, 60};

final var ret1 = buffer.put(0, src, 0, 1);
System.out.println(ret1); // java.nio.HeapIntBuffer[pos=0 lim=6 cap=6]
System.out.println(Arrays.toString(array)); // [10, 0, 0, 0, 0, 0]

final var ret2 = buffer.put(1, src, 1, 2);
System.out.println(ret2); // java.nio.HeapIntBuffer[pos=0 lim=6 cap=6]
System.out.println(Arrays.toString(array)); // [10, 20, 30, 0, 0, 0]

final var ret3 = buffer.put(3, src, 3, 3);
System.out.println(ret3); // java.nio.HeapIntBuffer[pos=0 lim=6 cap=6]
System.out.println(Arrays.toString(array)); // [10, 20, 30, 40, 50, 60]

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

IntBuffer put (int index, IntBuffer src, int offset, int length)

(optional operation)の絶対一括putメソッド。

final var array = new int[6];
final var buffer = IntBuffer.wrap(array);

System.out.println(buffer.capacity()); // 6
System.out.println(buffer.position()); // 0

final int[] srcArray = {10, 20, 30, 40, 50, 60};
final var src = IntBuffer.wrap(srcArray);

final var ret1 = buffer.put(0, src, 0, 1);
System.out.println(ret1); // java.nio.HeapIntBuffer[pos=0 lim=6 cap=6]
System.out.println(Arrays.toString(array)); // [10, 0, 0, 0, 0, 0]

final var ret2 = buffer.put(1, src, 1, 2);
System.out.println(ret2); // java.nio.HeapIntBuffer[pos=0 lim=6 cap=6]
System.out.println(Arrays.toString(array)); // [10, 20, 30, 0, 0, 0]

final var ret3 = buffer.put(3, src, 3, 3);
System.out.println(ret3); // java.nio.HeapIntBuffer[pos=0 lim=6 cap=6]
System.out.println(Arrays.toString(array)); // [10, 20, 30, 40, 50, 60]

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

IntBuffer put (IntBuffer src)

相対一括putメソッドです (オプションの操作)。

final var buffer = IntBuffer.allocate(5);

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

{
    final int[] array = {10, 20};
    final var src = IntBuffer.wrap(array);

    final var ret = buffer.put(src);
    System.out.println(ret); // java.nio.HeapIntBuffer[pos=2 lim=5 cap=5]
}
{
    final int[] array = {30, 40, 50};
    final var src = IntBuffer.wrap(array);

    final var ret = buffer.put(src);
    System.out.println(ret); // java.nio.HeapIntBuffer[pos=5 lim=5 cap=5]
}

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

if (buffer.hasArray()) {
    final var array = buffer.array();
    System.out.println(Arrays.toString(array)); // [10, 20, 30, 40, 50]
}

final IntBuffer reset ()

バッファの位置を以前にマークした位置に戻します。

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

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.HeapIntBuffer[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.HeapIntBuffer[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 IntBuffer rewind ()

このバッファをリワインド(巻き戻し)します。

final int[] array = {10, 20, 30, 40, 50};
final var 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 IntBuffer slice ()

このバッファの内容の共有のサブシーケンスを内容とする新しいintバッファを作成します。

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

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

final var sliced = buffer.slice();

System.out.println(buffer); // java.nio.HeapIntBuffer[pos=1 lim=4 cap=5]
System.out.println(sliced); // java.nio.HeapIntBuffer[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 IntBuffer slice (int index, int length)

このバッファの内容の共有のサブシーケンスを内容とする新しいintバッファを作成します。

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

final var sliced = buffer.slice(2, 3);

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

String toString ()

このバッファの状態を要約した文字列を返します。

final var buffer = IntBuffer.allocate(5)
        .limit(4)
        .position(2);

System.out.println(buffer.capacity()); // 5
System.out.println(buffer.limit()); // 4
System.out.println(buffer.position()); // 2

final var str1 = buffer.toString();
System.out.println(str1); // java.nio.HeapIntBuffer[pos=2 lim=4 cap=5]

buffer.clear();

final var str2 = buffer.toString();
System.out.println(str2); // java.nio.HeapIntBuffer[pos=0 lim=5 cap=5]

static IntBuffer wrap (int[] array)

int配列をバッファにラップします。

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

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

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
}

static IntBuffer wrap (int[] array, int offset, int length)

int配列をバッファにラップします。

final int[] array = {10, 20, 30, 40, 50, 60, 70};
final var buffer = IntBuffer.wrap(array, 2, 4);

System.out.println(buffer.capacity()); // 7
System.out.println(buffer.limit()); // 6
System.out.println(buffer.position()); // 2

if (buffer.hasArray()) {
    System.out.println(buffer.arrayOffset()); // 0

    System.out.println(buffer.get()); // 30
    System.out.println(buffer.get()); // 40
    System.out.println(buffer.get()); // 50
    System.out.println(buffer.get()); // 60
}

Bufferで宣言されたメソッド

capacity, hasRemaining, isReadOnly, limit, position, remaining

「Java API 使用例 : Buffer」をご参照ください。

API 使用例
- Buffer

Java : IntBuffer - API使用例

概要

メソッド

static IntBuffer allocate (int capacity)

final int[] array ()

final int arrayOffset ()

abstract IntBuffer asReadOnlyBuffer ()

final IntBuffer clear ()

abstract IntBuffer compact ()

int compareTo (IntBuffer that)

abstract IntBuffer duplicate ()

boolean equals (Object ob)

final IntBuffer flip ()

abstract int get ()

abstract int get (int index)

IntBuffer get (int[] dst)

IntBuffer get (int[] dst, int offset, int length)

IntBuffer get (int index, int[] dst)

IntBuffer get (int index, int[] dst, int offset, int length)

final boolean hasArray ()

int hashCode ()

abstract boolean isDirect ()

final IntBuffer limit (int newLimit)

final IntBuffer mark ()

int mismatch (IntBuffer that)

abstract ByteOrder order ()

final IntBuffer position (int newPosition)

abstract IntBuffer put (int i)

final IntBuffer put (int[] src)

IntBuffer put (int[] src, int offset, int length)

abstract IntBuffer put (int index, int i)

IntBuffer put (int index, int[] src)

IntBuffer put (int index, int[] src, int offset, int length)

IntBuffer put (int index, IntBuffer src, int offset, int length)

IntBuffer put (IntBuffer src)

final IntBuffer reset ()

final IntBuffer rewind ()

abstract IntBuffer slice ()

abstract IntBuffer slice (int index, int length)

String toString ()

static IntBuffer wrap (int[] array)

static IntBuffer wrap (int[] array, int offset, int length)

Bufferで宣言されたメソッド

capacity, hasRemaining, isReadOnly, limit, position, remaining

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