[Dubbo-2218] Fix the issuse: When using telnet "invoke" method, if there is a [null] param, the response always be [null] #2218 team3

[hexiloveecho]

What is the purpose of the change

fix issue #2218, by BaiJi the 269th team3

Brief changelog

When using telnet "invoke" method, if there is a [null] param, the response is not always null

Verifying this change

XXXXX

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[zhang2639]

You should use:

if (condition) {
        do_this();
        do_that();
} else if {
        otherwise();
} else {
        otherwise();
}

By team 5.