说明

io.netty.buffer.ByteBuf经常需要跟其它类型互相转化，例如ByteBuf类型作为Object类型函数参数传递，函数内部处理时将Object转换为ByteBuf。

代码示例

ByteBuf和Object类型互转

package com.thb;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;

public class Demo {

	public static void main(String[] args) {
		// 创建一个ByteBuf
		ByteBuf buf = Unpooled.buffer();
		// 将ByteBuf变量赋值给对象变量
		Object msg = buf;
		System.out.println("msg == buf: " + (msg == buf));
		
		if (msg instanceof ByteBuf) {  // 如果msg是ByteBuf类型
			// 将对象变量转化为ByteBuf变量
			ByteBuf buf2 = (ByteBuf)msg;
			
			System.out.println("buf2 == buf: " + (buf2 == buf));
			System.out.println("buf2 == msg: " + (buf2 == msg));
			System.out.println("buf.refCnt(): " + buf.refCnt());
			
			buf2.release();
			System.out.println("after call buf2 relase, buf.refCnt(): " + buf.refCnt());
		}
	}

}

运行输出：

msg == buf: true
buf2 == buf: true
buf2 == msg: true
buf.refCnt(): 1
after call buf2 relase, buf.refCnt(): 0