netty Exception in thread "main" java.net.SocketException: Permission denied

問題描述：
剛寫的netty demo，官網的demo；直接跑server的main方法
報錯如下

Exception in thread "main" java.net.SocketException: Permission denied
	at sun.nio.ch.Net.bind0(Native Method)
	at sun.nio.ch.Net.bind(Net.java:433)
	at sun.nio.ch.Net.bind(Net.java:425)
	at sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:223)
	at io.netty.channel.socket.nio.NioServerSocketChannel.doBind(NioServerSocketChannel.java:127)
	at io.netty.channel.AbstractChannel$AbstractUnsafe.bind(AbstractChannel.java:554)
	at io.netty.channel.DefaultChannelPipeline$HeadContext.bind(DefaultChannelPipeline.java:1258)
	at io.netty.channel.AbstractChannelHandlerContext.invokeBind(AbstractChannelHandlerContext.java:512)
	at io.netty.channel.AbstractChannelHandlerContext.bind(AbstractChannelHandlerContext.java:497)
	at io.netty.channel.DefaultChannelPipeline.bind(DefaultChannelPipeline.java:980)
	at io.netty.channel.AbstractChannel.bind(AbstractChannel.java:250)
	at io.netty.bootstrap.AbstractBootstrap$2.run(AbstractBootstrap.java:363)
	at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:163)
	at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:418)
	at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:454)
	at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:873)
	at io.netty.util.concurrent.DefaultThreadFactory$DefaultRunnableDecorator.run(DefaultThreadFactory.java:144)
	at java.lang.Thread.run(Thread.java:748)

一番周折，端口衝突了。我用了80端口，80端口被百度網盤佔用了

lsof -i:80