ByteBuffer buf = ByteBuffer.allocate(4);
// 写入整数9 ，1个整数4个字节
buf.putInt(9);

int value = buf.getInt();




import java.nio.ByteBuffer;
import java.util.Arrays;

public class ByteBufferTest {

    public static void main(String[] args) throws Exception {

        ByteBuffer buf = ByteBuffer.allocate(4);
        // java.nio.HeapByteBuffer[pos=0 lim=4 cap=4]
        System.out.println(buf.toString());
        // 写入整数9 ，1个整数4个字节
        buf.putInt(9);
        // java.nio.HeapByteBuffer[pos=4 lim=4 cap=4]
        System.out.println(buf.toString());
        // [0, 0, 0, 9]
        System.out.println(Arrays.toString(buf.array()));
        // 切换到读模式
        buf.flip();
        // java.nio.HeapByteBuffer[pos=0 lim=4 cap=4]
        System.out.println(buf.toString());
        // 读取并输出整数
        int value = buf.getInt();
        System.out.println("intValue=" + value);
        // java.nio.HeapByteBuffer[pos=4 lim=4 cap=4]
        System.out.println(buf.toString());

    }
}