Intercept a Request

import com.tvd12.ezyfox.core.annotation.ClientRequestListener;
import com.tvd12.ezyfox.core.annotation.RequestParam;
import com.tvd12.ezyfox.core.content.AppContext;
import com.tvd12.ezyfox.core.exception.BadRequestException;

@ClientRequestListener(command = "sum")
public class SumRequestInteceptor {
    
    @RequestParam private int a;
    @RequestParam private int b;
    
    public void execute(AppContext context, GameUser user) throws Exception {
        if(a == 0 || b == 0)
            // error code = 1 and response this error to client (false if don't need response to client)
            throw new BadRequestException("Unsupport negative number", 1, true); 
    }
}