Subj : Re: Problem using rhino under java
To   : webdel
From : Igor Bukanov
Date : Tue May 04 2004 12:40 pm

Danilo wrote:
> Hi, 
> I have this problem:
> 
> JAVA:
> 
> class one{
> 
>         public Integer ret(){
>                 return new Integer(12);
>         }
> }
> 
> 
> Context cx = Context.enter();
> try {
>         Scriptable scope = cx.initStandardObjects();
>         one o = new one();
>         Scriptable jsarg = Context.toObject(o,scope);
>         scope.put("o",scope,jsarg);
>         s=<JSCODE SEE DOWN>
>         try {
>                 Object result = cx.evaluateString(scope, s, "<cmd>", 1, null);
>         }catch (JavaScriptException ex) {
>           
>         } catch (Exception ee){
>            
>         }
> } catch (Exception ee){
>           
> } finally {
>           cx.exit();
> }
> 
>        
>       
>       
> JAVASCRIPT
> 
> var x=3
> x= x + o.ret()
> getWrapFactory()
> 
> the problem is that x value is "312" instead of 15.
> why interpreted o.ret() as String instead of Integer?

If you change "one"  into

class one{

         public int ret(){
                 return 12;
         }
}

then it should work as expected.

The problem is that by default in Rhino a Java object is always 
represented by a special wrapper even if the object is a "boxed" 
primitive type. When such wrapper is present on any side of "+", it 
forces string context for "+" that gives "312" in your example.

You can disable this wrapping of boxed values if you change

Context cx = Context.enter();
try {
     ....

into

Context cx = Context.enter();
try {
     cx.getWrapFactory().setJavaPrimitiveWrap(false);
     ....


Regards, Igor

.