Hi all,
i am new to struts2.. am struggling to get the result for populating items
from DB.
my requirement is to populate country, which is stored in DB, using struts2
and when u choose a particular country, another select box populate its
cities, which also stored in DB..
at first i tried, fetching the list from java class instead of DB... since
there is an example available in
struts2-showcase-2.0.14,built in project of struts2.
when i imported struts2-showcase-2.0.14 and tried that program the
<s:select> is working.. so i thought to implement that into my project.. but
unfortunately it is not working..
i will post here and please have a look and try providing the reason :)
I paste here the example block of a program from struts2-showcase-2.0.14 :
Portion of Jsp file contains the list Like : [b]example.jsp[/b]
<s:form action="exampleSubmit" >
<s:select
tooltip="Choose Your Favourite Language"
label="Favourite Language"
list="favouriteLanguages"
name="favouriteLanguage"
listKey="key"
listValue="description"
emptyOption="true"
headerKey="None"
headerValue="None"/>
portion of java class file contains like the following:
[b]UITagExample.java[/b]
package com.mobitail.action; // i pasted this since i mentioned this in
struts.xml - you should not confuse :)
public String execute() throws Exception {
return SUCCESS;
}
//constructor
public UITagExample() {
favouriteLanguages.add(new Language("EnglishKey", "English Language"));
favouriteLanguages.add(new Language("FrenchKey", "French Language"));
favouriteLanguages.add(new Language("SpanishKey", "Spanish Language"));
}
public List getFavouriteLanguages() {
return favouriteLanguages;
}
public void setFavouriteLanguage(String favouriteLanguage) {
this.favouriteLanguage = favouriteLanguage;
}
public String getFavouriteLanguage() {
return favouriteLanguage;
}
// === inner class
public static class Language {
String description;
String key;
public Language(String key, String description) {
this.key = key;
this.description = description;
}
public String getKey() {
return key;
}
public String getDescription() {
return description;
}
}
portion of [b]struts.xml[/b]
<action name="exampleSubmit" class="com.mobitail.action.UITagExample" >
<result>example.jsp</result>
<result name="input">example.jsp</result>
</action>
when i execute http://localhost:8080/mobitail.com/example.jsp .. result is a
blank page
if example.jsp contains other tags like <s:textfield> with <s:select> ,
result is only a textfield .. select box is not shown...
and in the Eclipse Ganymede output window, the error is like the following:
SEVERE: Servlet.service() for servlet jsp threw exception
tag 'select', field 'list', name 'favouriteLanguage': The requested list key
'favouriteLanguages' could not be resolved as a
collection/array/map/enumeration/iterator type. Example: people or
people.{name} - [unknown location]
at org.apache.struts2.components.Component.fieldError(Component.java:231)
at org.apache.struts2.components.Component.findValue(Component.java:293)
at
org.apache.struts2.components.ListUIBean.evaluateExtraParams(ListUIBean.java:79)
at org.apache.struts2.components.Select.evaluateExtraParams(Select.java:99)
at org.apache.struts2.components.UIBean.evaluateParams(UIBean.java:780)
at org.apache.struts2.components.UIBean.end(UIBean.java:481)
at
org.apache.struts2.views.jsp.ComponentTagSupport.doEndTag(ComponentTagSupport.java:43)
at
org.apache.jsp.example_jsp._jspx_meth_s_005fselect_005f0(example_jsp.java:383)
at
org.apache.jsp.example_jsp._jspx_meth_s_005fform_005f0(example_jsp.java:244)
at org.apache.jsp.example_jsp._jspService(example_jsp.java:111)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:374)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at
org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:416)
at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at
org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at
org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:286)
at
org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:845)
at
org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
at java.lang.Thread.run(Unknown Source)
I explained every single point detail in manner... i hope you guys can help
me by seeing this..
Please don't tell me to try the following: i tried and its working :)
<s:select
tooltip="Choose Your Favourite Color"
label="Favorite Color"
list="{'Red', 'Blue', 'Green'}"
name="favouriteColor"
emptyOption="true"
headerKey="None"
headerValue="None"/>
i need to populate from DB or from java class, like i explained at top
Thanks in advance...
I hope this post helps you lot...
Cheers!!!
Unnii
