import?java.io.ByteArrayOutputStream;
import?java.io.IOException;
import?java.io.UnsupportedEncodingException;
import?java.math.BigInteger;
import?java.net.InetSocketAddress;
import?java.net.SocketAddress;
import?java.nio.ByteBuffer;
import?java.nio.channels.DatagramChannel;
import?java.nio.channels.SelectionKey;
import?java.nio.channels.Selector;
import?java.text.SimpleDateFormat;
import?java.util.ArrayList;
import?java.util.Arrays;
import?java.util.Collections;
import?java.util.Date;
import?java.util.HashMap;
import?java.util.HashSet;
import?java.util.Iterator;
import?java.util.List;
import?java.util.Map;
import?java.util.Set;
import?java.util.Stack;
import?java.util.TreeMap;
import?java.util.TreeSet;
import?java.util.concurrent.BlockingQueue;
import?java.util.concurrent.CopyOnWriteArrayList;
import?java.util.concurrent.ExecutorService;
import?java.util.concurrent.Executors;
import?java.util.concurrent.linkedBlockingQueue;
import?java.util.concurrent.locks.Lock;
import?java.util.concurrent.locks.ReentrantLock;

public?class?Main?{
????
????public?static?void?main（String[]?args）?throws?Exception?{
????????//?填寫外網ip?百度一下ip就能看到了
????????final?byte[]?ip?=?{112?（byte）?65?（byte）?142?74};
????????//?如果想收到其他節點發送過來的消息必須把外網端口映射到內網端口?這里是內網端口?只要登錄路由器做一個端口映射就好
????????final?int?port?=?50000;
????????//?節點數?這里表示從50000到50255這256個端口將會被監聽
????????final?int?nodeCount?=?256;
????????final?int?processorCount?=?Runtime.getRuntime（）.availableProcessors（）;
????????final?String?id?=?“javadht:541241544“;
????????
????????List?ips?=?new?ArrayList<>（）;
????????List?ports?=?new?ArrayList<>（）;
????????List?ids?=?new?ArrayList<>（）;
????????for（int?i?=?0;?i?????????????if（i?%?（nodeCount?/?processorCount）?==?0?&&?ips.size（）?!=?0）?{
????????????????new?DHTServer（ips?ports?ids）;
????????????????ips?=?new?ArrayList<>（）;
????????????????ports?=?new?ArrayList<>（）;
????????????????ids?=?new?ArrayList<>（）;
????????????}
????????????ips.add（ip）;
????????????ports.add（port?+?i）;
????????????ids.add（（i?+?740）?+?id）;
????????}
????????if（ips.size（）?!=?0）?{
????????????new?DHTServer（ips?ports?ids）;
????????}
????}
}

interface?BencodeType?{
????int?getLength（）;
????int?getTotalLength（）;
????byte[]?getData（）;
????byte[]?getTotalData（）;
}

class?BencodeString?implements?BencodeType?Comparable?{
????
????private?final?String?content;
????
????public?BencodeString（String?content）?{
????????this.content?=?content;
????}
????
????public?BencodeString（byte[]?bs）?{
????????try?{
????????????this.content?=?new?String（bs?“iso-8859-1“）;
????????}?catch?（UnsupportedEncodingException?e）?{
????????????throw?new?RuntimeException（e）;
????????}
????}
????
????public?static?BencodeString?getString（String?source?int?index）?{
????????char?c?=?source.charAt（index）;
????????if（c?>=?‘1‘?&&?c?<=?‘9‘）?{
????????????source?=?source.substring（index）;
????