ByteBuffer類初探

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ByteBuffer簡介

ByteBuffer類是在Java NIO中經常使用的一個緩衝區類，使用它可以進行高效的存取操作。通過申請內存空間，作爲緩存區。ByteBuffer是個抽象的方法。

public abstract class ByteBuffer
        extends Buffer
        implements Comparable<ByteBuffer>

創建ByteBuffer對象的方法有：

public static ByteBuffer allocate(int capacity) {
        if (capacity < 0)
            throw new IllegalArgumentException();
        return new HeapByteBuffer(capacity, capacity);
}  //申請capacity字節大小的內存緩衝區

ByteBuffer.get();

取出當前position的byte, 並將position加1;

private void testByteBuffer() {
        String content = "testBuffer";
        ByteBuffer byteBuffer = ByteBuffer.wrap(content.getBytes());
        Log.d(TAG, "byteBuffer's position: " + byteBuffer.position());

        byte getContent = byteBuffer.get(); // position = position + 1
        Log.d(TAG, "byteBuffer's position: " + byteBuffer.position() + " get byte: " + getContent);

        getContent = byteBuffer.get();
        Log.d(TAG, "byteBuffer's position: " + byteBuffer.position() + " get byte: " + getContent);
    }

log:

D/TestByteBufferActivity: byteBuffer’s position: 0
D/TestByteBufferActivity: byteBuffer’s position: 1 get byte: 116
D/TestByteBufferActivity: byteBuffer’s position: 2 get byte: 101

t字符對應Ascii 116， e字符對應Ascii 101