一文解读java.nio.ByteBuffer

import java.nio.ByteBuffer;
public class JavaTest {
    public static void main(String[] args)
    {
        System.out.println("~~~~~~~~ put(byte b) ~~~~~~~~");
        // 分配一个5字节的buffer
        ByteBuffer byteBuffer = ByteBuffer.allocate(5);
        // 向buffer中添加两个字节的数据，空余3个字节数据
        byteBuffer.put((byte)10);
        byteBuffer.put((byte)20);
        // 输出整个字节数组
        printByteBuffer(byteBuffer);
        System.out.println("~~~~~~~~ flip() ~~~~~~~~");
        // 转为读模式
        byteBuffer.flip();
        // 输出整个字节数组
        printByteBuffer(byteBuffer);
        System.out.println("~~~~~~~~ get() ~~~~~~~~");
        // 读取当前 position 
        System.out.println(byteBuffer.get());
        // 输出整个字节数组
        printByteBuffer(byteBuffer);
        System.out.println("~~~~~~~~ rewind() ~~~~~~~~");
        // 倒回缓冲区的初始位置
        byteBuffer.rewind();
        printByteBuffer(byteBuffer);
        System.out.println("~~~~~~~~ get(byte[] dst, int offset, int length) ~~~~~~~~");
        // 将buffer中数据写入到dstBytes中
        byte[] dstBytes = new byte[2];
        byteBuffer.get(dstBytes, 0, dstBytes.length);
        printByteBuffer(byteBuffer);
    }
    public static void printByteBuffer(ByteBuffer byteBuffer) {
        byte[] bytes = byteBuffer.array();
        int position = byteBuffer.position();
        int limit = byteBuffer.limit();
        int remining = byteBuffer.remaining();
        System.out.println("byteBuffer: "
                + Arrays.toString(bytes)
                + "\nPosition: " + position
                + " Limit: " + limit
                + " Remining: " + remining);
    }
}

mark <= position <= limit <= capacity ​​​​​​​

ByteBuffer byteBuffer = ByteBuffer.allocate(5); 

byteBuffer.put((byte)'a') 

byteBuffer.get()