Re: java.applet.Applet.getParameter()

From:

"blaine@worldweb.com" <blaine@worldweb.com>

Newsgroups:

comp.lang.java.programmer

Date:

11 Jan 2007 11:38:36 -0800

Message-ID:

<1168544316.328123.82240@77g2000hsv.googlegroups.com>

Thanks Tomas.. Guess I missed that in the docs.

Thomas Fritsch wrote:

blaine@worldweb.com wrote:

I would like to test to see if a parameter exists in the html file
prior to calling getParameter(<key>), however I can not find any sort
of method to allow me to do this.

Is there a containsKey() method or something similar so that I could
write code like:

String[] keys = {"key1","key2"};
Hashtable ht = new Hashtable();

for(int i = 0; keys.length > i; i++){
    if ( <KEY EXISTS IN HTML PARAMETER LIST> ){
         ht.put(keys[i], getParameter(keys[i]);
    }
}

I know that I could just "try" and "catch" the getParameter, but this
does not seem as clean as just doing a test for existence.

Any help would be appreciated.

The getParameter(String) method is specified to return null, if the
parameter does not exist. Therefore, in you for-loop you can just do:
      String value = getParameter(keys[i]);
      if (value == null){
           ht.put(keys[i], value);
      }
There is no need for try/catch.

--
Thomas