Netty——ByteBuffer（ByteBuffer的内部结构演示示例）

一、pom.xml文件引入依赖

		
            io.netty
            netty-all
            4.1.39.Final
        
        
            org.projectlombok
            lombok
            1.16.18
        
        
            com.google.code.gson
            gson
            2.8.5
        
        
            com.google.guava
            guava
            19.0
        
        
            ch.qos.logback
            logback-classic
            1.2.3
        
        
            com.google.protobuf
            protobuf-java
            3.11.3
        

二、编写工具类（此工具类复制即可使用）

package com.example.nettytest.nio.day1;

import io.netty.util.internal.StringUtil;
import java.nio.ByteBuffer;
import static io.netty.util.internal.MathUtil.isOutOfBounds;
import static io.netty.util.internal.StringUtil.NEWLINE;

public class ByteBufferUtil {
    private static final char[] BYTE2CHAR = new char[256];
    private static final char[] HEXDUMP_TABLE = new char[256 * 4];
    private static final String[] HEXPADDING = new String[16];
    private static final String[] HEXDUMP_ROWPREFIXES = new String[65536 >>> 4];
    private static final String[] BYTE2HEX = new String[256];
    private static final String[] BYTEPADDING = new String[16];

    static {
        final char[] DIGITS = "0123456789abcdef".toCharArray();
        for (int i = 0; i  4 & 0x0F];
            HEXDUMP_TABLE[(i