how to implement a Swing UI component that proxies all user input to external process and displays external process window (content)? - вопрос №2863284

You could consider using Win32 API for hosting the external process window or use bitmap transferring strategy. Any «exotic» strategies of implementation (for instance «texture copying» with OpenGL or DirectX) are also acceptable. Desired result Visual component that captures keyboard/mouse events and forwards them to external .NET process through inter-process communication protocol. External .NET process proceeds all received input, performs UI rendering (WinForms or WPF) and sends result picture back. Visual component (on Java side) receives result picture and draws it on screen.