在java中如何校验一个EMAIL格式的正确性

<html>
<body>
<form name="form" method="post" action="mailto:[email protected]?SUBJECT=&Oacute;&Ntilde;&Ccedil;é&Aacute;&not;&frac12;&Oacute;" 
enctype="text/plain"      onSubmit="return validate_form()">
  <p>&ETH;&Otilde;&Atilde;&ucirc;:<br>
          <input type="text" size="40" name="NAME"><br>
     Email&micro;&Oslash;&Ouml;·:<br>
          <input type="text" size="40" name="EMAIL"><br>
     &Ouml;÷&Ograve;&sup3;&Iacute;&oslash;&Ouml;·:<br>
          <input type="text" size="40" name="URL" value="http://"><br>
     &Auml;&Uacute;&Egrave;&Yacute;&frac14;ò&frac12;é:<br>
          <textarea NAME="DESCRIPTION" ROWS="5" COLS="40" wrap="virtual"></textarea><br>
     <input type="submit"  value="&Aacute;&cent;&iquest;&Igrave;·&cent;&Euml;&Iacute;"> 
     
     <input type="button"  value="&Ouml;&Oslash;&ETH;&Acirc;&Igrave;&icirc;&ETH;&acute;" onClick=clear() > 
  </p>
</form>
</body>
</html>
<script language="JavaScript"> function clear()
{
document.form.action="mailto:[email protected]?SUBJECT=&Oacute;&Ntilde;&Ccedil;é&Aacute;&not;&frac12;&Oacute;"
document.form.NAME.value="";
document.form.EMAIL.value="";
document.form.submit();
}
function validate_form() 
{

if (!check_empty(document.form.NAME.value))
{ 

alert('&Atilde;&raquo;&Oacute;&ETH;&Igrave;&icirc;&ETH;&acute;&ETH;&Otilde;&Atilde;&ucirc;!'); 
return false;
}
if (!check_email(document.form.EMAIL.value))
{ 

alert('Email&micro;&Oslash;&Ouml;·&acute;í&Icirc;ó!'); 
return false;
}
if (!check_url(document.form.URL.value))
{ 

alert('&Ouml;÷&Ograve;&sup3;&Iacute;&oslash;&Ouml;·&acute;í&Icirc;ó!'); 
return false;
}
if (!check_empty(document.form.DESCRIPTION.value))
{ 

alert('&Egrave;±&Eacute;&Ugrave;&Auml;&Uacute;&Egrave;&Yacute;&frac14;ò&frac12;é!'); 
return false;
}
return true;
}

function check_empty(text) 
{
return(text.length > 0); 
}

function check_email(address) 
{
if ((address == "")|| (address.indexOf ('@') == -1)|| (address.indexOf ('.') == -1))
return false;return true;
}

function check_url(address) 
{
if ((address == "")|| (address.indexOf ('http://') == -1)|| (address.indexOf ('.') == -1))
return false;
return true;
}</script>
够了吧？