基于Java、JavaFX开发的下载工具，支持下载协议：BT（BitTorrent、磁力链接、种子文件）、HLS（M3U8）等

package com.acgist.snail.net.torrent.peer; import java.net.InetSocketAddress; import java.nio.ByteBuffer; import java.util.Arrays; import java.util.BitSet; import com.acgist.snail.config.PeerConfig; import com.acgist.snail.config.PeerConfig.Type; import com.acgist.snail.config.SystemConfig; import com.acgist.snail.logger.Logger; import com.acgist.snail.logger.LoggerFactory; import com.acgist.snail.net.NetException; import com.acgist.snail.net.codec.IMessageDecoder; import com.acgist.snail.net.torrent.IEncryptMessageSender; import com.acgist.snail.net.torrent.IPeerConnect; import com.acgist.snail.net.torrent.TorrentContext; import com.acgist.snail.net.torrent.TorrentSession; import com.acgist.snail.utils.ArrayUtils; import com.acgist.snail.utils.BitfieldUtils; import com.acgist.snail.utils.ByteUtils; import com.acgist.snail.utils.NumberUtils; import com.acgist.snail.utils.StringUtils; /** * Peer消息代理（TCP/UDP） * * The BitTorrent Protocol Specification * 协议链接：http://www.bittorrent.org/beps/bep_0003.html * Fast Extension * 协议链接：http://www.bittorrent.org/beps/bep_0006.html * Private Torrents * 协议链接：http://www.bittorrent.org/beps/bep_0027.html * * Peer状态标识：https://baike.baidu.com/item/uTorrent/8195186 * * @author acgist */ public final class PeerSubMessageHandler implements IMessageDecoder<ByteBuffer>, IPeerConnect { private static final Logger LOGGER = LoggerFactory.getLogger(PeerSubMessageHandler.class); /** * 检查是否使用最大次数：{@value} */ private static final int MAX_USELESS_CHECK = 3; /** * 检查是否使用次数 */ private int uselessCheck = 0; /** * 是否可用 */ private volatile boolean available = false; /** * 是否已经发送握手 */ private volatile boolean handshakeSend = false; /** * 是否已经处理握手 */ private volatile boolean handshakeRecv = false; /** * 是否是服务端 */ private final boolean server; /** * Peer连接 * * @see PeerUploader * @see PeerDownloader */ private PeerConnect peerConnect; /** * Peer信息 */ private PeerSession peerSession; /** * BT任务信息 */ private TorrentSession torrentSession; /** * Peer连接信息 */ private PeerConnectSession peerConnectSession; /** * 加密消息代理 */ private IEncryptMessageSender messageEncryptSender; /** * 扩展消息代理 */ private ExtensionMessageHandler extensionMessageHandler; /** * DHT扩展消息代理 */ private DhtExtensionMessageHandler dhtExtensionMessageHandler; /** * 服务端 */ private PeerSubMessageHandler() { this.server = true; } /** * 客户端 * * @param peerSession Peer信息 * @param torrentSession BT任务信息 */ private PeerSubMessageHandler(PeerSession peerSession, TorrentSession torrentSession) { this.server = false; this.init(peerSession, torrentSession); } /** * 服务端 * * @return PeerSubMessageHandler */ public static final PeerSubMessageHandler newInstance() { return new PeerSubMessageHandler(); } /** * 客户端 * * @param peerSession Peer信息 * @param torrentSession BT任务信息 * * @return PeerSubMessageHandler */ public static final PeerSubMessageHandler newInstance(PeerSession peerSession, TorrentSession torrentSession) { return new PeerSubMessageHandler(peerSession, torrentSession); } /** * 初始消息代理 * * @param peerSession Peer信息 * @param torrentSession BT任务信息 */ private void init(PeerSession peerSession, TorrentSession torrentSession) { this.peerSession = peerSession; this.torrentSession = torrentSession; this.extensionMessageHandler = ExtensionMessageHandler.newInstance(this.peerSession, this.torrentSession, this); this.dhtExtensionMessageHandler = DhtExtensionMessageHandler.newInstance(this.peerSession, this.torrentSession, this); } /** * 初始化服务端 * * @param infoHashHex InfoHashHex * @param peerId PeerId * * @return 是否成功 */ private boolean initServer(String infoHashHex, byte[] peerId) { if(Arrays.equals(PeerConfig.getInstance().getPeerId(), peerId)) { LOGGER.debug("Peer接入失败（PeerId一致）"); return false; } final TorrentSession torrentSession = TorrentContext.getInstance().torrentSession(infoHashHex); if(torrentSession == null) { LOGGER.debug("Peer接入失败（种子信息不存在）：{}", infoHashHex); return false; } if(!torrentSession.useable()) { LOGGER.debug("Peer接入失败（任务没有准备完成）：{}", infoHashHex); return false; } final InetSocketAddress socketAddress = this.remoteSocketAddress(); if(socketAddress == null) { LOGGER.debug("Peer接入失败（远程客户端获取失败）：{}", infoHashHex); return false; } // 禁止自动获取端口：通过PEX消息获取端口 final PeerSession peerSession = PeerContext.getInstance().newPeerSession( infoHashHex, torrentSession.statistics(), socketAddress.getHostString(), null, PeerConfig.Source.CONNECT ); final PeerUploader peerUploader = torrentSession.newPeerUploader(peerSession, this); if(peerUploader == null) { return false; } else { this.init(peerSession, torrentSession); this.peerConnect = peerUploader; this.peerConnectSession = peerUploader.peerConnectSession(); this.peerSession.peerUploader(peerUploader); return true; } } /** * 初始化客户端 * * @param peerDownloader Peer下载 * * @return Peer消息代理 */ public PeerSubMessageHandler initClient(PeerDownloader peerDownloader) { this.peerConnect = peerDownloader; this.peerConnectSession = peerDownloader.peerConnectSession(); this.peerSession.peerDownloader(peerDownloader); return this; } /** * 判断是否没有使用 * * @return 是否没有使用 */ public boolean useless() { if(this.handshakeRecv) { return false; } return ++this.uselessCheck > MAX_USELESS_CHECK; } /** * 判断是否处理握手消息 * * @return 是否处理握手消息 */ public boolean handshakeRecv() { return this.handshakeRecv; } /** * @return BT任务信息 */ public TorrentSession torrentSession() { return this.torrentSession; } /** * 判断是否需要加密 * * @return 是否需要加密 * * @see PeerSession#encrypt() */ public boolean needEncrypt() { if(this.peerSession == null) { // 默认使用明文 return false; } return this.peerSession.encrypt(); } /** * 设置实际消息代理：TCP、UDP（UTP） * * @param messageEncryptSender 实际消息代理 * * @return Peer消息代理 */ public PeerSubMessageHandler messageEncryptSender(IEncryptMessageSender messageEncryptSender) { this.messageEncryptSender = messageEncryptSender; return this; } @Override public final IPeerConnect.ConnectType connectType() { return this.messageEncryptSender.connectType(); } @Override public void onMessa