按照課程代碼敲了遍，運行后結果如下

java.net.BindException: Address already in use: JVM_Bind

at java.net.DualStackPlainSocketImpl.bind0(Native Method)

at java.net.DualStackPlainSocketImpl.socketBind(DualStackPlainSocketImpl.java:106)

at java.net.AbstractPlainSocketImpl.bind(AbstractPlainSocketImpl.java:382)

at java.net.PlainSocketImpl.bind(PlainSocketImpl.java:190)

at java.net.ServerSocket.bind(ServerSocket.java:375)

at java.net.ServerSocket.<init>(ServerSocket.java:237)

at java.net.ServerSocket.<init>(ServerSocket.java:128)

at com.imooc.Server.main(Server.java:21)

請問這個怎么解決？（老師敲得代碼下載下來導入運行后也是這個結果）-_-