JSP page initial loading method

When writing a page, I met the need to automatically load when I entered the page , The method of page initialization loading is specially sorted out , as follows ：

 (1)// Page initialization loading
    $(document).ready(function(){

    alert(" The first method .");   

    } 

(2)// Page initialization loading

 $(function(){  

          alert(" The second method .");  

 });  

(3)// Page initialization loading

  jQuery(function($) {  

    alert(" The third method .");  

  });

(4)// Page initialization loading

   window.οnlοad=function(){  

    alert(" The fourth method .");  

    }  

(5)// Page initialization loading

stay body It says in it onload