Support TCP keepalive count/interval/idle options and jdk11.

[angelyouyou]

Support TCP keepalive count/interval/idle options and jdk11.

[angelyouyou]

@bernd @joschi @lennartkoopmann @dennisoelkers
I have made the current software support TCP related features, please help me to merge the code, thank you very much.

[CLAassistant]

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