You are viewing a plain text version of this content. The canonical link for it is here.
Posted to issues@struts.apache.org by "Jaron Schut (JIRA)" <ji...@apache.org> on 2009/05/26 18:18:42 UTC
[jira] Updated: (WW-3140) converts the "listKey" to
String before comparing to the Object in "value"
[ https://issues.apache.org/struts/browse/WW-3140?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Jaron Schut updated WW-3140:
----------------------------
Description:
Trying to get a populated and preselected select tag to work. Well, countries is a list of country objects and country is a singular object of the preselected country. Data comes from hibernate so are identified by Long objects:
<s:select list="countries" name="countryId" listKey="id" listValue="displayLabel" value="country.id" />
Now the preselecting does not work because the tag converts the listKey, which is a Long object to a string before calling the equals method on the Long object in the value. So a Long object and a String object are never equal.
Changing the tag to:
<s:select list="countries" name="countryId" listKey="id" listValue="displayLabel" value="%{country.id}" />
Still does not correctly preselect the value because struts2 call Long.toString() 2 separate times and then compares the result by reference. Which obviously is String != String.
Conclusion: <s:select> tag is not able to correctly compare 2 objects that are the same nor correctly compare a single object because it creates 2 new strings that apparently are not compared by value but only by reference?
PS: changing the tag to:
<s:select list="countries" name="countryCode" listKey="countryCode" listValue="displayLabel" value="country.countryCode" />
Did work correctly. Since the list of countries and the singular country all come from hibernate. The tag ends up comparing 2 exactly the same languageCode Strings (Same instance) correctly.
was:
Trying to get a populated and preselected select tag to work. Well, countries is a list of country objects and country is a singular object of the preselected country. Data comes from hibernate so are identified by Long objects:
<s:select list="countries" name="countryId" listKey="id" listValue="displayLabel" value="country.id" />
Now the preselecting does not work because the tag converts the listKey, which is a Long object to a string before calling the equals method on the Long object in the value. So a Long object and a String object are never equal.
Changing the tag to:
<s:select list="countries" name="countryId" listKey="id" listValue="displayLabel" value="%{country.id}" />
Still does not correctly preselect the value because struts2 call Long.toString() 2 separate times and then compares the result by reference. Which obviously is String != String.
Conclusion: <s:select> tag is not able to correctly compare 2 objects that are the same nor correctly compare a single object because it creates 2 new strings that apparently are not compared by value but only by reference?
PS: changing the tag to:
<s:select list="countries" name="countryCode" listKey="countryCode" listValue="displayLabel" value="country.countryCode" />
Did work correctly. Since but the list of countries and the singular country all come from hibernate. The tag ends up comparing 2 exactly the same languageCode Strings (Same instance) to correctly.
> <s:select> converts the "listKey" to String before comparing to the Object in "value"
> -------------------------------------------------------------------------------------
>
> Key: WW-3140
> URL: https://issues.apache.org/struts/browse/WW-3140
> Project: Struts 2
> Issue Type: Improvement
> Components: Plugin - Tags
> Affects Versions: 2.0.6
> Environment: Jetty, all OS'es
> Reporter: Jaron Schut
>
> Trying to get a populated and preselected select tag to work. Well, countries is a list of country objects and country is a singular object of the preselected country. Data comes from hibernate so are identified by Long objects:
> <s:select list="countries" name="countryId" listKey="id" listValue="displayLabel" value="country.id" />
> Now the preselecting does not work because the tag converts the listKey, which is a Long object to a string before calling the equals method on the Long object in the value. So a Long object and a String object are never equal.
> Changing the tag to:
> <s:select list="countries" name="countryId" listKey="id" listValue="displayLabel" value="%{country.id}" />
> Still does not correctly preselect the value because struts2 call Long.toString() 2 separate times and then compares the result by reference. Which obviously is String != String.
> Conclusion: <s:select> tag is not able to correctly compare 2 objects that are the same nor correctly compare a single object because it creates 2 new strings that apparently are not compared by value but only by reference?
> PS: changing the tag to:
> <s:select list="countries" name="countryCode" listKey="countryCode" listValue="displayLabel" value="country.countryCode" />
> Did work correctly. Since the list of countries and the singular country all come from hibernate. The tag ends up comparing 2 exactly the same languageCode Strings (Same instance) correctly.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.