How to attach my java code to my plugin project

Please help me...i dont now how i can create my plugin...my java code is ready.i want this code be a plugin

Please refer to https://www.jetbrains.com/help/idea/plugin-development-guidelines.html .

Place your Java code in the src (source root) of the plug-in project.

this is my plugin project...what is my wrong?what can i do???

Please clarify the problem.

Look...i never wrote a plugin project...i just wrote a java code...can you tell me how i can create a plugin project from first step?

Please check https://www.youtube.com/watch?v=-ZmQD6Fr6KE.

i watched this video before...this video didnt show attaching java code to plugin project...my original java code has main class...i think in plugin project we should not have this class...

assume that i want wrote a plugin to say hello to user...its java code is very simple.just has a system out...but how i transform it to a plugin?

You either create an action which will trigger your code or you create a component that is executed at certain point (when IDE is started or when project is open), please refer to https://www.jetbrains.org/intellij/sdk/docs/basics/plugin_structure/plugin_components.html#plugin-components-lifecycle for details.