how to use fcitx5 in java applications

[cooscode]

My os is linux, and my desktop environment is kde plasma 6, wayland.

I cannot switch to Chinese input method on java applications, such as jd-gui, IntelliJ IDEA, jadx and so on.

Even if, I export the environment variables, like this:

XMODIFIERS=@im=fcitx
GTK_IM_MODULE=fcitx
QT_IM_MODULE=fcitx
LC_CTYPE=zh_CN.UTF-8

I still cannot use shortcut ctrl+space to switch to the other input mehtod.