How to write this code shorter using switch?

I think I get what you're trying to do now. In that case, I think you'd want something like this:

class MyClass implements OnMenuItemClickListener {

    /* whatever function you're setting up the controls in */ {
        /* ... */
        
        exit_app = menu.getItem(7);
        text_enter = menu.getItem(1);
        /* ... */
        
        exit_app.setOnMenuItemClickListener(this);
        text_enter.setOnMenuItemClickListener(this);
        /* ... */
    }

    public boolean onMenuItemClick(MenuItem clickedItem)
    {
        switch (clickedItem.getId()) {
            case R.id.exit_app:
                //Exit the App
                try{
                    _run = false;
                finish();
                }catch(Exception c)
                {
                    c.toString();
                }
                return true;
            case R.id.text_enter:
                _run = false;

                try{
                    Thread.sleep(1000);
                    setContentView(R.layout.text_enter);
                    buttonCancel.setOnClickListener(buttonSendOnClickListener);
                }catch(Exception x)
                {
                    x.toString();
                }
                return true;
            /* ... */
        }
    }
}

But a few more things: the numbers used in menu.GetItem should be made into constants, for example:

static final int EXIT_APP_MENU_INDEX = 7;

Also, the function with the switch won't compile as-is, it will need to return a value either after the switch or in a default case.