Fix java code examples in README

[MichaelMorrisEst]

Fixes #3091

[juntao]

Hello, I am a code review bot on flows.network. Here are my reviews of code commits in this PR.

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[dannypsnl]

It seems before this you need to fix the binding, from my check, the CI failed in a week.

[alabulei1]

Hi @MichaelMorrisEst ,

Can you please check out the CI tests? Thanks.

[hydai]

Hi @MichaelMorrisEst
Please rebase to the latest master, GitHub doesn't allow me to merge this PR.

[MichaelMorrisEst]

Hi @hydai
PR is now rebased

[dannypsnl]

Oops, we don't use merge, try rebase or cherry-pick again.

[hydai]

Hi @MichaelMorrisEst
I still cannot process the merge due to the following reason:

It seems like the DCO check is not working. Could you please rebase and force-push the branch to trigger the DCO check again?

[MichaelMorrisEst]

Sorry, yes I did a merge rather than rebase. I have rebased now and force pushed, so hopefully all ok now

[hydai]

Hi @MichaelMorrisEst
I just realized that the DCO bot is stuck due to an upstream issue.
A workaround PR is merged: #3451
Please rebase again to ensure the DCO check is working. Thanks.

[hydai]

Thanks @MichaelMorrisEst 👍