Apache License
Version 2.0, January 2004
http://www.apache.org/licenses/
TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
1. Definitions.
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END OF TERMS AND CONDITIONS
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如果开发者想基于本系统开发自己的即时通讯服务，大部分时间只需要实现消息处理器CmdHandler的回调接口即可：