Java : ByteBuffer 示例

Java 中的 ByteBuffer (Java SE 22 & JDK 22) 及其示例。
您将找到大多数 ByteBuffer 方法的代码示例。

注解 :

本文可能使用了翻译软件以方便阅读。另请查看英文原文。

简介

一个字节缓冲区。 (机器翻译)

Class diagram

final var buffer = ByteBuffer.allocate(5);

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

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

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

buffer.put((byte) 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.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

final ByteBuffer alignedSlice (int unitSize)

创建一个新的字节缓冲区，其内容是此缓冲区内容的共享和对齐子序列。 (机器翻译)

Please see also : alignmentOffset(int index, int unitSize)

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

    System.out.println("unitSize = " + unitSize);
    for (int i = 0; i < 8; i++) {
        System.out.println("------");

        buffer.position(i);
        System.out.println("position = " + buffer.position());

        final var sliced = buffer.alignedSlice(unitSize);
        final var dst = new byte[sliced.remaining()];

        sliced.get(dst);
        System.out.println(Arrays.toString(dst));
    }
}

test(1);

// Result
// ↓
//unitSize = 1
//------
//position = 0
//[10, 20, 30, 40, 50, 60, 70, 80]
//------
//position = 1
//[20, 30, 40, 50, 60, 70, 80]
//------
//position = 2
//[30, 40, 50, 60, 70, 80]
//------
//position = 3
//[40, 50, 60, 70, 80]
//------
//position = 4
//[50, 60, 70, 80]
//------
//position = 5
//[60, 70, 80]
//------
//position = 6
//[70, 80]
//------
//position = 7
//[80]

test(2);

// Result
// ↓
//unitSize = 2
//------
//position = 0
//[10, 20, 30, 40, 50, 60, 70, 80]
//------
//position = 1
//[30, 40, 50, 60, 70, 80]
//------
//position = 2
//[30, 40, 50, 60, 70, 80]
//------
//position = 3
//[50, 60, 70, 80]
//------
//position = 4
//[50, 60, 70, 80]
//------
//position = 5
//[70, 80]
//------
//position = 6
//[70, 80]
//------
//position = 7
//[]

test(4);

// Result
// ↓
//unitSize = 4
//------
//position = 0
//[10, 20, 30, 40, 50, 60, 70, 80]
//------
//position = 1
//[50, 60, 70, 80]
//------
//position = 2
//[50, 60, 70, 80]
//------
//position = 3
//[50, 60, 70, 80]
//------
//position = 4
//[50, 60, 70, 80]
//------
//position = 5
//[]
//------
//position = 6
//[]
//------
//position = 7
//[]

final int alignmentOffset (int index, int unitSize)

返回指向给定索引处的字节的内存地址，对给定的单位大小取模。 (机器翻译)

Please see also : alignedSlice(int unitSize)

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

System.out.println("--- unitSize = 1 ---");
for (int i = 0; i < array.length; i++) {
    final var ret = buffer.alignmentOffset(i, 1);
    System.out.println("index = " + i + " : offset = " + ret);
}

System.out.println();
System.out.println("--- unitSize = 2 ---");
for (int i = 0; i < array.length; i++) {
    final var ret = buffer.alignmentOffset(i, 2);
    System.out.println("index = " + i + " : offset = " + ret);
}

System.out.println();
System.out.println("--- unitSize = 4 ---");
for (int i = 0; i < array.length; i++) {
    final var ret = buffer.alignmentOffset(i, 4);
    System.out.println("index = " + i + " : offset = " + ret);
}

// Result
// ↓
//--- unitSize = 1 ---
//index = 0 : offset = 0
//index = 1 : offset = 0
//index = 2 : offset = 0
//index = 3 : offset = 0
//index = 4 : offset = 0
//index = 5 : offset = 0
//index = 6 : offset = 0
//index = 7 : offset = 0
//
//--- unitSize = 2 ---
//index = 0 : offset = 0
//index = 1 : offset = 1
//index = 2 : offset = 0
//index = 3 : offset = 1
//index = 4 : offset = 0
//index = 5 : offset = 1
//index = 6 : offset = 0
//index = 7 : offset = 1
//
//--- unitSize = 4 ---
//index = 0 : offset = 0
//index = 1 : offset = 1
//index = 2 : offset = 2
//index = 3 : offset = 3
//index = 4 : offset = 0
//index = 5 : offset = 1
//index = 6 : offset = 2
//index = 7 : offset = 3

static ByteBuffer allocate (int capacity)

分配一个新的字节缓冲区。 (机器翻译)

Please see also : allocateDirect(int capacity)

final var buffer = ByteBuffer.allocate(5);

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

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

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

static ByteBuffer allocateDirect (int capacity)

分配一个新的直接字节缓冲区。 (机器翻译)

Please see also : allocate(int capacity)

final var buffer = ByteBuffer.allocateDirect(5);

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

System.out.println(buffer.isDirect()); // true
System.out.println(buffer.hasArray()); // false

final byte[] array ()

返回支持此缓冲区的字节数组（可选操作）。 (机器翻译)

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

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

final int arrayOffset ()

返回此缓冲区的支持数组中缓冲区第一个元素的偏移量（可选操作）。 (机器翻译)

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

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

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
}

abstract CharBuffer asCharBuffer ()

将此字节缓冲区的视图创建为字符缓冲区。 (机器翻译)

final var array = new byte[6];

final var buffer = ByteBuffer.wrap(array);
System.out.println(buffer.capacity()); // 6
System.out.println(buffer.limit()); // 6
System.out.println(buffer.position()); // 0

final var charBuffer = buffer.asCharBuffer();
System.out.println(charBuffer.capacity()); // 3
System.out.println(charBuffer.limit()); // 3
System.out.println(charBuffer.position()); // 0

System.out.println(Arrays.toString(array)); // [0, 0, 0, 0, 0, 0]

charBuffer.put('a');
System.out.println(Arrays.toString(array)); // [0, 97, 0, 0, 0, 0]

charBuffer.put('b');
System.out.println(Arrays.toString(array)); // [0, 97, 0, 98, 0, 0]

charBuffer.put('c');
System.out.println(Arrays.toString(array)); // [0, 97, 0, 98, 0, 99]

abstract DoubleBuffer asDoubleBuffer ()

将此字节缓冲区的视图创建为双缓冲区。 (机器翻译)

final var array = new byte[16];

final var buffer = ByteBuffer.wrap(array);
System.out.println(buffer.capacity()); // 16
System.out.println(buffer.limit()); // 16
System.out.println(buffer.position()); // 0

final var doubleBuffer = buffer.asDoubleBuffer();
System.out.println(doubleBuffer.capacity()); // 2
System.out.println(doubleBuffer.limit()); // 2
System.out.println(doubleBuffer.position()); // 0

// [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
System.out.println(Arrays.toString(array));

doubleBuffer.put(123.45);

// [64, 94, -36, -52, -52, -52, -52, -51, 0, 0, 0, 0, 0, 0, 0, 0]
System.out.println(Arrays.toString(array));

doubleBuffer.put(-0.789);

// [64, 94, -36, -52, -52, -52, -52, -51, -65, -23, 63, 124, -19, -111, 104, 115]
System.out.println(Arrays.toString(array));

abstract FloatBuffer asFloatBuffer ()

将此字节缓冲区的视图创建为浮点缓冲区。 (机器翻译)

final var array = new byte[8];

final var buffer = ByteBuffer.wrap(array);
System.out.println(buffer.capacity()); // 8
System.out.println(buffer.limit()); // 8
System.out.println(buffer.position()); // 0

final var floatBuffer = buffer.asFloatBuffer();
System.out.println(floatBuffer.capacity()); // 2
System.out.println(floatBuffer.limit()); // 2
System.out.println(floatBuffer.position()); // 0

// [0, 0, 0, 0, 0, 0, 0, 0]
System.out.println(Arrays.toString(array));

floatBuffer.put(123.45f);

// [66, -10, -26, 102, 0, 0, 0, 0]
System.out.println(Arrays.toString(array));

floatBuffer.put(-0.789f);

// [66, -10, -26, 102, -65, 73, -5, -25]
System.out.println(Arrays.toString(array));

abstract IntBuffer asIntBuffer ()

将此字节缓冲区的视图创建为 int 缓冲区。 (机器翻译)

final var array = new byte[8];

final var buffer = ByteBuffer.wrap(array);
System.out.println(buffer.capacity()); // 8
System.out.println(buffer.limit()); // 8
System.out.println(buffer.position()); // 0

final var intBuffer = buffer.asIntBuffer();
System.out.println(intBuffer.capacity()); // 2
System.out.println(intBuffer.limit()); // 2
System.out.println(intBuffer.position()); // 0

// [0, 0, 0, 0, 0, 0, 0, 0]
System.out.println(Arrays.toString(array));

intBuffer.put(123456789);

// [7, 91, -51, 21, 0, 0, 0, 0]
System.out.println(Arrays.toString(array));

intBuffer.put(-1);

// [7, 91, -51, 21, -1, -1, -1, -1]
System.out.println(Arrays.toString(array));

abstract LongBuffer asLongBuffer ()

将此字节缓冲区的视图创建为长缓冲区。 (机器翻译)

final var array = new byte[16];

final var buffer = ByteBuffer.wrap(array);
System.out.println(buffer.capacity()); // 16
System.out.println(buffer.limit()); // 16
System.out.println(buffer.position()); // 0

final var longBuffer = buffer.asLongBuffer();
System.out.println(longBuffer.capacity()); // 2
System.out.println(longBuffer.limit()); // 2
System.out.println(longBuffer.position()); // 0

// [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
System.out.println(Arrays.toString(array));

longBuffer.put(1234567890123456789L);

// [17, 34, 16, -12, 125, -23, -127, 21, 0, 0, 0, 0, 0, 0, 0, 0]
System.out.println(Arrays.toString(array));

longBuffer.put(-1L);

// [17, 34, 16, -12, 125, -23, -127, 21, -1, -1, -1, -1, -1, -1, -1, -1]
System.out.println(Arrays.toString(array));

abstract ByteBuffer asReadOnlyBuffer ()

创建一个新的、只读的字节缓冲区，并共享此缓冲区的内容。 (机器翻译)

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

final var readOnlyBuffer = buffer.asReadOnlyBuffer();

System.out.println(buffer); // java.nio.HeapByteBuffer[pos=1 lim=3 cap=3]
System.out.println(readOnlyBuffer); // java.nio.HeapByteBufferR[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((byte) 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((byte) 30);
} catch (ReadOnlyBufferException e) {
    System.out.println("ReadOnlyBufferException!");
}

// Result
// ↓
//ReadOnlyBufferException!

abstract ShortBuffer asShortBuffer ()

将此字节缓冲区的视图创建为短缓冲区。 (机器翻译)

final var array = new byte[4];

final var buffer = ByteBuffer.wrap(array);
System.out.println(buffer.capacity()); // 4
System.out.println(buffer.limit()); // 4
System.out.println(buffer.position()); // 0

final var shortBuffer = buffer.asShortBuffer();
System.out.println(shortBuffer.capacity()); // 2
System.out.println(shortBuffer.limit()); // 2
System.out.println(shortBuffer.position()); // 0

// [0, 0, 0, 0]
System.out.println(Arrays.toString(array));

shortBuffer.put((short) 1234);

// [4, -46, 0, 0]
System.out.println(Arrays.toString(array));

shortBuffer.put((short) -1);

// [4, -46, -1, -1]
System.out.println(Arrays.toString(array));

ByteBuffer clear ()

清除此缓冲区。 (机器翻译)

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

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 ByteBuffer compact ()

压缩此缓冲区（可选操作）。 (机器翻译)

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

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

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

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

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

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

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

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

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

int compareTo (ByteBuffer that)

将此缓冲区与另一个缓冲区进行比较。 (机器翻译)

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

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

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

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

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

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

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

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

System.out.println(buffer1.compareTo(buffer2)); // 5
System.out.println(buffer1.compareTo(buffer3)); // -20

abstract ByteBuffer duplicate ()

创建一个共享此缓冲区内容的新字节缓冲区。 (机器翻译)

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

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

final var duplicated = buffer.duplicate();

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

boolean equals (Object ob)

判断该缓冲区是否等于另一个对象。 (机器翻译)

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

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

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

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

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

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

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

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

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

ByteBuffer flip ()

翻转此缓冲区。 (机器翻译)

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

相对获取方法。 (机器翻译)

final byte[] array = {10, 20, 30, 40, 50};
final var buffer = ByteBuffer.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

ByteBuffer get (byte[] dst)

相对批量获取方法。 (机器翻译)

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

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

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

    final var ret = buffer.get(dst);
    System.out.println(ret); // java.nio.HeapByteBuffer[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 byte[3];
    System.out.println(Arrays.toString(dst)); // [0, 0, 0]

    final var ret = buffer.get(dst);
    System.out.println(ret); // java.nio.HeapByteBuffer[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 byte[3];
    var _ = buffer.get(dst);
} catch (BufferUnderflowException e) {
    System.out.println("BufferUnderflowException!");
}

// Result
// ↓
//BufferUnderflowException!

ByteBuffer get (byte[] dst, int offset, int length)

相对批量获取方法。 (机器翻译)

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

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

{
    final var dst = new byte[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.HeapByteBuffer[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 byte[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.HeapByteBuffer[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 byte[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.HeapByteBuffer[pos=8 lim=8 cap=8]

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

abstract byte get (int index)

绝对获取方法。 (机器翻译)

final byte[] array = {10, 20, 30, 40, 50};
final var buffer = ByteBuffer.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

ByteBuffer get (int index, byte[] dst)

绝对批量获取方法。 (机器翻译)

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

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

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

    final var ret = buffer.get(0, dst);
    System.out.println(ret); // java.nio.HeapByteBuffer[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 byte[3];
    System.out.println(Arrays.toString(dst)); // [0, 0, 0]

    final var ret = buffer.get(1, dst);
    System.out.println(ret); // java.nio.HeapByteBuffer[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 byte[3];
    System.out.println(Arrays.toString(dst)); // [0, 0, 0]

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

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

ByteBuffer get (int index, byte[] dst, int offset, int length)

绝对批量获取方法。 (机器翻译)

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

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

{
    final var dst = new byte[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.HeapByteBuffer[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 byte[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.HeapByteBuffer[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 byte[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.HeapByteBuffer[pos=0 lim=6 cap=6]

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

abstract char getChar ()

用于读取字符值的相对获取方法。 (机器翻译)

final var array = new byte[6];
final var buffer = ByteBuffer.wrap(array)
        .putChar('a')
        .putChar('b')
        .putChar('c')
        .clear();

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

// [0, 97, 0, 98, 0, 99]
System.out.println(Arrays.toString(array));

System.out.println(buffer.getChar()); // a
System.out.println(buffer.position()); // 2

System.out.println(buffer.getChar()); // b
System.out.println(buffer.position()); // 4

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

abstract char getChar (int index)

用于读取字符值的绝对获取方法。 (机器翻译)

final var array = new byte[6];
final var buffer = ByteBuffer.wrap(array)
        .putChar('a')
        .putChar('b')
        .putChar('c')
        .clear();

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

// [0, 97, 0, 98, 0, 99]
System.out.println(Arrays.toString(array));

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

System.out.println(buffer.getChar(2)); // b
System.out.println(buffer.position()); // 0

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

abstract double getDouble ()

用于读取双精度值的相对获取方法。 (机器翻译)

final var array = new byte[16];
final var buffer = ByteBuffer.wrap(array)
        .putDouble(123.45)
        .putDouble(-0.789)
        .clear();

System.out.println(buffer.capacity()); // 16
System.out.println(buffer.position()); // 0

// [64, 94, -36, -52, -52, -52, -52, -51, -65, -23, 63, 124, -19, -111, 104, 115]
System.out.println(Arrays.toString(array));

System.out.println(buffer.getDouble()); // 123.45
System.out.println(buffer.position()); // 8

System.out.println(buffer.getDouble()); // -0.789
System.out.println(buffer.position()); // 16

abstract double getDouble (int index)

用于读取双精度值的绝对获取方法。 (机器翻译)

final var array = new byte[16];
final var buffer = ByteBuffer.wrap(array)
        .putDouble(123.45)
        .putDouble(-0.789)
        .clear();

System.out.println(buffer.capacity()); // 16
System.out.println(buffer.position()); // 0

// [64, 94, -36, -52, -52, -52, -52, -51, -65, -23, 63, 124, -19, -111, 104, 115]
System.out.println(Arrays.toString(array));

System.out.println(buffer.getDouble(0)); // 123.45
System.out.println(buffer.position()); // 0

System.out.println(buffer.getDouble(8)); // -0.789
System.out.println(buffer.position()); // 0

abstract float getFloat ()

用于读取浮点值的相对获取方法。 (机器翻译)

final var array = new byte[8];
final var buffer = ByteBuffer.wrap(array)
        .putFloat(123.45f)
        .putFloat(-0.789f)
        .clear();

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

// [66, -10, -26, 102, -65, 73, -5, -25]
System.out.println(Arrays.toString(array));

System.out.println(buffer.getFloat()); // 123.45
System.out.println(buffer.position()); // 4

System.out.println(buffer.getFloat()); // -0.789
System.out.println(buffer.position()); // 8

abstract float getFloat (int index)

读取浮点值的绝对获取方法。 (机器翻译)

final var array = new byte[8];
final var buffer = ByteBuffer.wrap(array)
        .putFloat(123.45f)
        .putFloat(-0.789f)
        .clear();

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

// [66, -10, -26, 102, -65, 73, -5, -25]
System.out.println(Arrays.toString(array));

System.out.println(buffer.getFloat(0)); // 123.45
System.out.println(buffer.position()); // 0

System.out.println(buffer.getFloat(4)); // -0.789
System.out.println(buffer.position()); // 0

abstract int getInt ()

用于读取 int 值的相对获取方法。 (机器翻译)

final var array = new byte[8];
final var buffer = ByteBuffer.wrap(array)
        .putInt(12345)
        .putInt(-789)
        .clear();

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

// [0, 0, 48, 57, -1, -1, -4, -21]
System.out.println(Arrays.toString(array));

System.out.println(buffer.getInt()); // 12345
System.out.println(buffer.position()); // 4

System.out.println(buffer.getInt()); // -789
System.out.println(buffer.position()); // 8

abstract int getInt (int index)

用于读取 int 值的绝对获取方法。 (机器翻译)

final var array = new byte[8];
final var buffer = ByteBuffer.wrap(array)
        .putInt(12345)
        .putInt(-789)
        .clear();

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

// [0, 0, 48, 57, -1, -1, -4, -21]
System.out.println(Arrays.toString(array));

System.out.println(buffer.getInt(0)); // 12345
System.out.println(buffer.position()); // 0

System.out.println(buffer.getInt(4)); // -789
System.out.println(buffer.position()); // 0

abstract long getLong ()

用于读取长值的相对获取方法。 (机器翻译)

final var array = new byte[16];
final var buffer = ByteBuffer.wrap(array)
        .putLong(12345L)
        .putLong(-789L)
        .clear();

System.out.println(buffer.capacity()); // 16
System.out.println(buffer.position()); // 0

// [0, 0, 0, 0, 0, 0, 48, 57, -1, -1, -1, -1, -1, -1, -4, -21]
System.out.println(Arrays.toString(array));

System.out.println(buffer.getLong()); // 12345
System.out.println(buffer.position()); // 8

System.out.println(buffer.getLong()); // -789
System.out.println(buffer.position()); // 16

abstract long getLong (int index)

用于读取长值的绝对获取方法。 (机器翻译)

final var array = new byte[16];
final var buffer = ByteBuffer.wrap(array)
        .putLong(12345L)
        .putLong(-789L)
        .clear();

System.out.println(buffer.capacity()); // 16
System.out.println(buffer.position()); // 0

// [0, 0, 0, 0, 0, 0, 48, 57, -1, -1, -1, -1, -1, -1, -4, -21]
System.out.println(Arrays.toString(array));

System.out.println(buffer.getLong(0)); // 12345
System.out.println(buffer.position()); // 0

System.out.println(buffer.getLong(8)); // -789
System.out.println(buffer.position()); // 0

abstract short getShort ()

用于读取短值的相对获取方法。 (机器翻译)

final var array = new byte[4];
final var buffer = ByteBuffer.wrap(array)
        .putShort((short) 12345)
        .putShort((short) -789)
        .clear();

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

// [48, 57, -4, -21]
System.out.println(Arrays.toString(array));

System.out.println(buffer.getShort()); // 12345
System.out.println(buffer.position()); // 2

System.out.println(buffer.getShort()); // -789
System.out.println(buffer.position()); // 4

abstract short getShort (int index)

用于读取短值的绝对获取方法。 (机器翻译)

final var array = new byte[4];
final var buffer = ByteBuffer.wrap(array)
        .putShort((short) 12345)
        .putShort((short) -789)
        .clear();

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

// [48, 57, -4, -21]
System.out.println(Arrays.toString(array));

System.out.println(buffer.getShort(0)); // 12345
System.out.println(buffer.position()); // 0

System.out.println(buffer.getShort(2)); // -789
System.out.println(buffer.position()); // 0

final boolean hasArray ()

告知此缓冲区是否由可访问的字节数组支持。 (机器翻译)

final var buffer = ByteBuffer.allocate(5)
        .put((byte) 10)
        .put((byte) 20)
        .put((byte) 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 = ByteBuffer.allocate(5)
        .put((byte) 10)
        .put((byte) 20)
        .put((byte) 30)
        .asReadOnlyBuffer();

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

// Result
// ↓
//UnsupportedOperationException!

int hashCode ()

返回此缓冲区的当前哈希码。 (机器翻译)

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

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

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

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

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

abstract boolean isDirect ()

告知该字节缓冲区是否是直接的。 (机器翻译)

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

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

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

ByteBuffer limit (int newLimit)

设置此缓冲区的限制。 (机器翻译)

final byte[] array = {10, 20, 30, 40, 50};
final var 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.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!

ByteBuffer mark ()

在此缓冲区的位置设置其标记。 (机器翻译)

final byte[] array = {10, 20, 30, 40, 50};
final var buffer = ByteBuffer.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.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

int mismatch (ByteBuffer that)

查找并返回此缓冲区与给定缓冲区之间第一个不匹配的相对索引。 (机器翻译)

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

{
    final byte[] a = {10};
    final var that = ByteBuffer.wrap(a);

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

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

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

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

    System.out.println(buffer.mismatch(that)); // 4
}
{
    final byte[] a = {10, 20, 99};
    final var that = ByteBuffer.wrap(a); // 2

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

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

final ByteOrder order ()

检索此缓冲区的字节顺序。 (机器翻译)

final var array = new byte[4];
final var buffer = ByteBuffer.wrap(array)
        .putInt(1234567890)
        .clear();

System.out.println(buffer.order()); // BIG_ENDIAN

System.out.println(Arrays.toString(array)); // [73, -106, 2, -46]
System.out.println(buffer.getInt(0)); // 1234567890

final var ret = buffer.order(ByteOrder.LITTLE_ENDIAN);
System.out.println(ret); // java.nio.HeapByteBuffer[pos=0 lim=4 cap=4]
System.out.println(buffer.order()); // LITTLE_ENDIAN

System.out.println(Arrays.toString(array)); // [73, -106, 2, -46]
System.out.println(buffer.getInt(0)); // -771582391

final ByteBuffer order (ByteOrder bo)

修改此缓冲区的字节顺序。 (机器翻译)

final var array = new byte[4];
final var buffer = ByteBuffer.wrap(array)
        .putInt(1234567890)
        .clear();

System.out.println(buffer.order()); // BIG_ENDIAN

System.out.println(Arrays.toString(array)); // [73, -106, 2, -46]
System.out.println(buffer.getInt(0)); // 1234567890

final var ret = buffer.order(ByteOrder.LITTLE_ENDIAN);
System.out.println(ret); // java.nio.HeapByteBuffer[pos=0 lim=4 cap=4]
System.out.println(buffer.order()); // LITTLE_ENDIAN

System.out.println(Arrays.toString(array)); // [73, -106, 2, -46]
System.out.println(buffer.getInt(0)); // -771582391

ByteBuffer position (int newPosition)

设置此缓冲区的位置。 (机器翻译)

final byte[] array = {10, 20, 30, 40, 50};
final var buffer = ByteBuffer.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.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

abstract ByteBuffer put (byte b)

相对放置方法（可选操作）。 (机器翻译)

final var buffer = ByteBuffer.allocate(5);

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

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

相对批量放入方法（可选操作）。 (机器翻译)

final var buffer = ByteBuffer.allocate(6);

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

{
    final byte[] src = {10};

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

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

    final var ret = buffer.put(src);
    System.out.println(ret); // java.nio.HeapByteBuffer[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]
}

ByteBuffer put (byte[] src, int offset, int length)

相对批量放入方法（可选操作）。 (机器翻译)

final var array = new byte[6];
final var buffer = ByteBuffer.wrap(array);

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

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

final var ret1 = buffer.put(src, 0, 1);
System.out.println(ret1); // java.nio.HeapByteBuffer[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.HeapByteBuffer[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.HeapByteBuffer[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 ByteBuffer put (int index, byte b)

绝对put方法（可选操作）。 (机器翻译)

final var buffer = ByteBuffer.allocate(5);

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

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

ByteBuffer put (int index, byte[] src)

绝对批量放入方法（可选操作）。 (机器翻译)

final var buffer = ByteBuffer.allocate(6);

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

{
    final byte[] src = {10};

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

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

    final var ret = buffer.put(3, src);
    System.out.println(ret); // java.nio.HeapByteBuffer[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]
}

ByteBuffer put (int index, byte[] src, int offset, int length)

绝对批量放入方法（可选操作）。 (机器翻译)

final var array = new byte[6];
final var buffer = ByteBuffer.wrap(array);

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

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

final var ret1 = buffer.put(0, src, 0, 1);
System.out.println(ret1); // java.nio.HeapByteBuffer[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.HeapByteBuffer[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.HeapByteBuffer[pos=0 lim=6 cap=6]
System.out.println(Arrays.toString(array)); // [10, 20, 30, 40, 50, 60]

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

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

绝对批量放入方法（可选操作）。 (机器翻译)

final var array = new byte[6];
final var buffer = ByteBuffer.wrap(array);

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

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

final var ret1 = buffer.put(0, src, 0, 1);
System.out.println(ret1); // java.nio.HeapByteBuffer[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.HeapByteBuffer[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.HeapByteBuffer[pos=0 lim=6 cap=6]
System.out.println(Arrays.toString(array)); // [10, 20, 30, 40, 50, 60]

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

ByteBuffer put (ByteBuffer src)

相对批量放入方法（可选操作）。 (机器翻译)

final var buffer = ByteBuffer.allocate(5);

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

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

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

    final var ret = buffer.put(src);
    System.out.println(ret); // java.nio.HeapByteBuffer[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]
}

abstract ByteBuffer putChar (char value)

用于写入 char 值的相对 put 方法（可选操作）。 (机器翻译)

final var array = new byte[6];
final var buffer = ByteBuffer.wrap(array);

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

final var ret1 = buffer.putChar('a');
System.out.println(ret1); // java.nio.HeapByteBuffer[pos=2 lim=6 cap=6]
System.out.println(buffer.position()); // 2

// [0, 97, 0, 0, 0, 0]
System.out.println(Arrays.toString(array));

final var ret2 = buffer.putChar('b');
System.out.println(ret2); // java.nio.HeapByteBuffer[pos=4 lim=6 cap=6]
System.out.println(buffer.position()); // 4

// [0, 97, 0, 98, 0, 0]
System.out.println(Arrays.toString(array));

final var ret3 = buffer.putChar('c');
System.out.println(ret3); // java.nio.HeapByteBuffer[pos=6 lim=6 cap=6]
System.out.println(buffer.position()); // 6

// [0, 97, 0, 98, 0, 99]
System.out.println(Arrays.toString(array));

abstract ByteBuffer putChar (int index, char value)

用于写入 char 值的绝对 put 方法（可选操作）。 (机器翻译)

final var array = new byte[6];
final var buffer = ByteBuffer.wrap(array);

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

final var ret1 = buffer.putChar(0, 'a');
System.out.println(ret1); // java.nio.HeapByteBuffer[pos=0 lim=6 cap=6]
System.out.println(buffer.position()); // 0

// [0, 97, 0, 0, 0, 0]
System.out.println(Arrays.toString(array));

final var ret2 = buffer.putChar(2, 'b');
System.out.println(ret2); // java.nio.HeapByteBuffer[pos=0 lim=6 cap=6]
System.out.println(buffer.position()); // 0

// [0, 97, 0, 98, 0, 0]
System.out.println(Arrays.toString(array));

final var ret3 = buffer.putChar(4, 'c');
System.out.println(ret3); // java.nio.HeapByteBuffer[pos=0 lim=6 cap=6]
System.out.println(buffer.position()); // 0

// [0, 97, 0, 98, 0, 99]
System.out.println(Arrays.toString(array));

abstract ByteBuffer putDouble (double value)

用于写入双精度值的相对 put 方法（可选操作）。 (机器翻译)

final var array = new byte[16];
final var buffer = ByteBuffer.wrap(array);

System.out.println(buffer.capacity()); // 16
System.out.println(buffer.position()); // 0

final var ret1 = buffer.putDouble(123.45);
System.out.println(ret1); // java.nio.HeapByteBuffer[pos=8 lim=16 cap=16]
System.out.println(buffer.position()); // 8

// [64, 94, -36, -52, -52, -52, -52, -51, 0, 0, 0, 0, 0, 0, 0, 0]
System.out.println(Arrays.toString(array));

final var ret2 = buffer.putDouble(-0.789);
System.out.println(ret2); // java.nio.HeapByteBuffer[pos=16 lim=16 cap=16]
System.out.println(buffer.position()); // 16

// [64, 94, -36, -52, -52, -52, -52, -51, -65, -23, 63, 124, -19, -111, 104, 115]
System.out.println(Arrays.toString(array));

abstract ByteBuffer putDouble (int index, double value)

用于写入双精度值的绝对 put 方法（可选操作）。 (机器翻译)

final var array = new byte[16];
final var buffer = ByteBuffer.wrap(array);

System.out.println(buffer.capacity()); // 16
System.out.println(buffer.position()); // 0

final var ret1 = buffer.putDouble(0, 123.45);
System.out.println(ret1); // java.nio.HeapByteBuffer[pos=0 lim=16 cap=16]
System.out.println(buffer.position()); // 0

// [64, 94, -36, -52, -52, -52, -52, -51, 0, 0, 0, 0, 0, 0, 0, 0]
System.out.println(Arrays.toString(array));

final var ret2 = buffer.putDouble(8, -0.789);
System.out.println(ret2); // java.nio.HeapByteBuffer[pos=0 lim=16 cap=16]
System.out.println(buffer.position()); // 0

// [64, 94, -36, -52, -52, -52, -52, -51, -65, -23, 63, 124, -19, -111, 104, 115]
System.out.println(Arrays.toString(array));

abstract ByteBuffer putFloat (float value)

用于写入浮点值的相对 put 方法（可选操作）。 (机器翻译)

final var array = new byte[8];
final var buffer = ByteBuffer.wrap(array);

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

final var ret1 = buffer.putFloat(123.45f);
System.out.println(ret1); // java.nio.HeapByteBuffer[pos=4 lim=8 cap=8]
System.out.println(buffer.position()); // 4

// [66, -10, -26, 102, 0, 0, 0, 0]
System.out.println(Arrays.toString(array));

final var ret2 = buffer.putFloat(-0.789f);
System.out.println(ret2); // java.nio.HeapByteBuffer[pos=8 lim=8 cap=8]
System.out.println(buffer.position()); // 8

// [66, -10, -26, 102, -65, 73, -5, -25]
System.out.println(Arrays.toString(array));

abstract ByteBuffer putFloat (int index, float value)

用于写入浮点值的绝对 put 方法（可选操作）。 (机器翻译)

final var array = new byte[8];
final var buffer = ByteBuffer.wrap(array);

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

final var ret1 = buffer.putFloat(0, 123.45f);
System.out.println(ret1); // java.nio.HeapByteBuffer[pos=0 lim=8 cap=8]
System.out.println(buffer.position()); // 0

// [66, -10, -26, 102, 0, 0, 0, 0]
System.out.println(Arrays.toString(array));

final var ret2 = buffer.putFloat(4, -0.789f);
System.out.println(ret2); // java.nio.HeapByteBuffer[pos=0 lim=8 cap=8]
System.out.println(buffer.position()); // 0

// [66, -10, -26, 102, -65, 73, -5, -25]
System.out.println(Arrays.toString(array));

abstract ByteBuffer putInt (int value)

用于写入 int 值的相对 put 方法（可选操作）。 (机器翻译)

final var array = new byte[8];
final var buffer = ByteBuffer.wrap(array);

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

final var ret1 = buffer.putInt(12345);
System.out.println(ret1); // java.nio.HeapByteBuffer[pos=4 lim=8 cap=8]
System.out.println(buffer.position()); // 4

// [0, 0, 48, 57, 0, 0, 0, 0]
System.out.println(Arrays.toString(array));

final var ret2 = buffer.putInt(-789);
System.out.println(ret2); // java.nio.HeapByteBuffer[pos=8 lim=8 cap=8]
System.out.println(buffer.position()); // 8

// [0, 0, 48, 57, -1, -1, -4, -21]
System.out.println(Arrays.toString(array));

abstract ByteBuffer putInt (int index, int value)

用于写入 int 值的绝对 put 方法（可选操作）。 (机器翻译)

final var array = new byte[8];
final var buffer = ByteBuffer.wrap(array);

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

final var ret1 = buffer.putInt(0, 12345);
System.out.println(ret1); // java.nio.HeapByteBuffer[pos=0 lim=8 cap=8]
System.out.println(buffer.position()); // 0

// [0, 0, 48, 57, 0, 0, 0, 0]
System.out.println(Arrays.toString(array));

final var ret2 = buffer.putInt(4, -789);
System.out.println(ret2); // java.nio.HeapByteBuffer[pos=0 lim=8 cap=8]
System.out.println(buffer.position()); // 0

// [0, 0, 48, 57, -1, -1, -4, -21]
System.out.println(Arrays.toString(array));

abstract ByteBuffer putLong (int index, long value)

用于写入长值的绝对放入方法（可选操作）。 (机器翻译)

final var array = new byte[16];
final var buffer = ByteBuffer.wrap(array);

System.out.println(buffer.capacity()); // 16
System.out.println(buffer.position()); // 0

final var ret1 = buffer.putLong(0, 12345L);
System.out.println(ret1); // java.nio.HeapByteBuffer[pos=0 lim=16 cap=16]
System.out.println(buffer.position()); // 0

// [0, 0, 0, 0, 0, 0, 48, 57, 0, 0, 0, 0, 0, 0, 0, 0]
System.out.println(Arrays.toString(array));

final var ret2 = buffer.putLong(8, -789L);
System.out.println(ret2); // java.nio.HeapByteBuffer[pos=0 lim=16 cap=16]
System.out.println(buffer.position()); // 0

// [0, 0, 0, 0, 0, 0, 48, 57, -1, -1, -1, -1, -1, -1, -4, -21]
System.out.println(Arrays.toString(array));

abstract ByteBuffer putLong (long value)

用于写入长值的相对 put 方法（可选操作）。 (机器翻译)

final var array = new byte[16];
final var buffer = ByteBuffer.wrap(array);

System.out.println(buffer.capacity()); // 16
System.out.println(buffer.position()); // 0

final var ret1 = buffer.putLong(12345L);
System.out.println(ret1); // java.nio.HeapByteBuffer[pos=8 lim=16 cap=16]
System.out.println(buffer.position()); // 8

// [0, 0, 0, 0, 0, 0, 48, 57, 0, 0, 0, 0, 0, 0, 0, 0]
System.out.println(Arrays.toString(array));

final var ret2 = buffer.putLong(-789L);
System.out.println(ret2); // java.nio.HeapByteBuffer[pos=16 lim=16 cap=16]
System.out.println(buffer.position()); // 16

// [0, 0, 0, 0, 0, 0, 48, 57, -1, -1, -1, -1, -1, -1, -4, -21]
System.out.println(Arrays.toString(array));

abstract ByteBuffer putShort (int index, short value)

用于写入短值的绝对 put 方法（可选操作）。 (机器翻译)

final var array = new byte[4];
final var buffer = ByteBuffer.wrap(array);

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

final var ret1 = buffer.putShort(0, (short) 12345);
System.out.println(ret1); // java.nio.HeapByteBuffer[pos=0 lim=4 cap=4]
System.out.println(buffer.position()); // 0

// [48, 57, 0, 0]
System.out.println(Arrays.toString(array));

final var ret2 = buffer.putShort(2, (short) -789);
System.out.println(ret2); // java.nio.HeapByteBuffer[pos=0 lim=4 cap=4]
System.out.println(buffer.position()); // 0

// [48, 57, -4, -21]
System.out.println(Arrays.toString(array));

abstract ByteBuffer putShort (short value)

用于写入短值的相对 put 方法（可选操作）。 (机器翻译)

final var array = new byte[4];
final var buffer = ByteBuffer.wrap(array);

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

final var ret1 = buffer.putShort((short) 12345);
System.out.println(ret1); // java.nio.HeapByteBuffer[pos=2 lim=4 cap=4]
System.out.println(buffer.position()); // 2

// [48, 57, 0, 0]
System.out.println(Arrays.toString(array));

final var ret2 = buffer.putShort((short) -789);
System.out.println(ret2); // java.nio.HeapByteBuffer[pos=4 lim=4 cap=4]
System.out.println(buffer.position()); // 4

// [48, 57, -4, -21]
System.out.println(Arrays.toString(array));

ByteBuffer reset ()

将此缓冲区的位置重置为先前标记的位置。 (机器翻译)

final byte[] array = {10, 20, 30, 40, 50};
final var buffer = ByteBuffer.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.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

ByteBuffer rewind ()

倒回此缓冲区。 (机器翻译)

final byte[] array = {10, 20, 30, 40, 50};
final var buffer = ByteBuffer.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.HeapByteBuffer[pos=0 lim=4 cap=5]

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

abstract ByteBuffer slice ()

创建一个新的字节缓冲区，其内容是此缓冲区内容的共享子序列。 (机器翻译)

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

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

final var sliced = buffer.slice();

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 ByteBuffer slice (int index, int length)

创建一个新的字节缓冲区，其内容是此缓冲区内容的共享子序列。 (机器翻译)

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

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

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

String toString ()

返回概括此缓冲区状态的字符串。 (机器翻译)

final var buffer = ByteBuffer.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.HeapByteBuffer[pos=2 lim=4 cap=5]

buffer.clear();

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

static ByteBuffer wrap (byte[] array)

将字节数组包装到缓冲区中。 (机器翻译)

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

将字节数组包装到缓冲区中。 (机器翻译)

final byte[] array = {10, 20, 30, 40, 50, 60, 70};
final var buffer = ByteBuffer.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
}

Methods declared in Buffer

capacity, hasRemaining, isReadOnly, limit, position, remaining

请参阅下面的链接。

Buffer 示例

API 示例
- Buffer

Java : ByteBuffer 示例

简介

Methods

final ByteBuffer alignedSlice (int unitSize)

final int alignmentOffset (int index, int unitSize)

static ByteBuffer allocate (int capacity)

static ByteBuffer allocateDirect (int capacity)

final byte[] array ()

final int arrayOffset ()

abstract CharBuffer asCharBuffer ()

abstract DoubleBuffer asDoubleBuffer ()

abstract FloatBuffer asFloatBuffer ()

abstract IntBuffer asIntBuffer ()

abstract LongBuffer asLongBuffer ()

abstract ByteBuffer asReadOnlyBuffer ()

abstract ShortBuffer asShortBuffer ()

ByteBuffer clear ()

abstract ByteBuffer compact ()

int compareTo (ByteBuffer that)

abstract ByteBuffer duplicate ()

boolean equals (Object ob)

ByteBuffer flip ()

abstract byte get ()

ByteBuffer get (byte[] dst)

ByteBuffer get (byte[] dst, int offset, int length)

abstract byte get (int index)

ByteBuffer get (int index, byte[] dst)

ByteBuffer get (int index, byte[] dst, int offset, int length)

abstract char getChar ()

abstract char getChar (int index)

abstract double getDouble ()

abstract double getDouble (int index)

abstract float getFloat ()

abstract float getFloat (int index)

abstract int getInt ()

abstract int getInt (int index)

abstract long getLong ()

abstract long getLong (int index)

abstract short getShort ()

abstract short getShort (int index)

final boolean hasArray ()

int hashCode ()

abstract boolean isDirect ()

ByteBuffer limit (int newLimit)

ByteBuffer mark ()

int mismatch (ByteBuffer that)

final ByteOrder order ()

final ByteBuffer order (ByteOrder bo)

ByteBuffer position (int newPosition)

abstract ByteBuffer put (byte b)

final ByteBuffer put (byte[] src)

ByteBuffer put (byte[] src, int offset, int length)

abstract ByteBuffer put (int index, byte b)

ByteBuffer put (int index, byte[] src)

ByteBuffer put (int index, byte[] src, int offset, int length)

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

ByteBuffer put (ByteBuffer src)

abstract ByteBuffer putChar (char value)

abstract ByteBuffer putChar (int index, char value)

abstract ByteBuffer putDouble (double value)

abstract ByteBuffer putDouble (int index, double value)

abstract ByteBuffer putFloat (float value)

abstract ByteBuffer putFloat (int index, float value)

abstract ByteBuffer putInt (int value)

abstract ByteBuffer putInt (int index, int value)

abstract ByteBuffer putLong (int index, long value)

abstract ByteBuffer putLong (long value)

abstract ByteBuffer putShort (int index, short value)

abstract ByteBuffer putShort (short value)

ByteBuffer reset ()

ByteBuffer rewind ()

abstract ByteBuffer slice ()

abstract ByteBuffer slice (int index, int length)

String toString ()

static ByteBuffer wrap (byte[] array)

static ByteBuffer wrap (byte[] array, int offset, int length)

Methods declared in Buffer

capacity, hasRemaining, isReadOnly, limit, position, remaining

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