bean in or out scope?

[Bob CHOI]

My code below

package p;
public class B {
private String p = "default";
public void setP(String p) {
this.p = p;
}
public String getP() {
return p;
}
}

<%
request.setAttribute("b", new p.B());
%>
<jsp:useBean id="b" class="p.B" scope="session">
<jsp:setProperty name="b" property="p" value="new"/>
</jsp:useBean>
${requestScope.b.p} <p>
${sessionScope.b.p} <p>

what i had expected below,

default
new

the jsp page responded below,

new
default

Why?

[Stary Kapec]

I think I understand why,

at the time the <jsp:setProperty name="b" property="p" value="new"/> is executed, there exist two beans named b. One in request scope the other in session scope.

setProperty tag does not accept scope attribute so it starts to search through all scopes starting with page scope, then request scope and so on. It sets the property of the first bean found.

In your example it sets the "new" value to the bean in the request scope so the bean in session scope is left uninitialized.

[ January 08, 2007: Message edited by: Jasiek Motyka ]
[ January 09, 2007: Message edited by: Jasiek Motyka ]

[Bob CHOI]

Thanks Jasiek

i also tried out myself, in short,

- set/getAttribute methods: always scoped
- jsp:useBean: always scoped
- jsp:set/getProperty: scope order from request, session and likewards
- EL bean without scope prefix, scope order from request, session and likewards
- EL bean with scope prefix, always scoped

[Amirr Rafique]

 

jsp:set/getProperty: scope order from request, session and likewards

Can anyone tell the complete search order

[Stary Kapec]

Scopes are searched from the narrowest to the widest. From page scope, request scope, session scope to the application scope.