trying to capture ""

[sde]

<%
if( request.getParameters("name") == "" ) {
  out.println("No Name Selected");
}
%>

ok, really basic here i'm sure. i have a form with a text field 'name'. when there is nothing in that field, i want it to trigger the above if statment.

for some reason, i can not catch "" .. the value is NOT null either because i'm sending the field.

here would be the html form:

<form method=post action=test.jsp>
name: <input type=text name=name> <input type=submit name=submit value=submit>
</form>

how can i print 'no name selected' if someone submits the form without anything in it? ( no client side stuff )

so basic hehe, .. php spoils me.

[Belisarius]

"==" doesn't do what you think it does. You want equals()."==" compares the pointers of two objects.

[Belisarius]

Oh, and as a followup, I recently discovered that "==" will sometimes return true, even in instances it shouldn't due to java optimizations. Don't use "==" to compare objects, only use it to compare primitives. Always use equals() to compare objects.

[sde]

thanks!

[Belisarius]

On the subject of best practices, you might want to check to make sure whatever you're using equals with isn't null, or else a NullPointerException will get thrown.

The way I usually tackle the problem is

if(input == null){
input = "";
}
return input.trim();

[sde]

so then to do what i was explaining, maybe try this?

if(input == null){
  input = "";
}

if(input.trim().equals(""))
{
  out.println("Please enter a name.");
}

[Belisarius]

Yep, that would cover the possibility of input being null. You could create a method to do it, so you don't need as many lines of code.