是Apache开源的XMPP协议客户端类库,用于实现即时通讯和聊天,它是Spark项目的核心,主要包括smack-core.jar、smack-tcp.jar、smack-extensions.jar、smack-experimental.jar、smack-legacy.jar、smack-bosh.jar、smack-jingle.jar、smack-resolver-dnsjava.jar、smack-resolver-javax.jar、smack-debug.jar几个组件包。