Struts 2 <s:checkboxlist> multiple check boxes example
In Struts 2 , you can use the <s:checkboxlist> tag to create multiple check boxes with a same name. The only concern is how to hold the multiple checked values in a variable? For example,
public List<String> getColors() { colors = new ArrayList<String>(); colors.add("red"); colors.add("yellow"); colors.add("blue"); colors.add("green"); return colors; }
<s:checkboxlist label="What's your favor color" list="colors" name="yourColor" value="defaultColor" />
A multiple check boxes with “red”, “yellow”, “blue” and “green” options. If multiple options are checked, you can store it via a String object.
For example, If “red” and “yellow” options are checked, the checked values will combine with a comma, yourColor = “red,yellow”.
private String yourColor; public void setYourColor(String yourColor) { this.yourColor = yourColor; }
Struts 2 <s:checkboxlist> example
A full Struts 2 example to create multiple check boxes with a same name via <s:checkboxlist>, stored the checked values and display it in another page.
1. Action
Action class to generate and hold the multiple check boxes values.
CheckBoxListAction.java
package com.mkyong.common.action; import java.util.ArrayList; import java.util.List; import com.opensymphony.xwork2.ActionSupport; public class CheckBoxListAction extends ActionSupport{ private List<String> colors; private String yourColor; public String getYourColor() { return yourColor; } public void setYourColor(String yourColor) { this.yourColor = yourColor; } public CheckBoxListAction(){ colors = new ArrayList<String>(); colors.add("red"); colors.add("yellow"); colors.add("blue"); colors.add("green"); } public String[] getDefaultColor(){ return new String [] {"red", "green"}; } public List<String> getColors() { return colors; } public void setColors(List<String> colors) { this.colors = colors; } public String execute() { return SUCCESS; } public String display() { return NONE; } }
2. Result page
Render the multiple check boxes via “s:checkboxlist” tag.
checkBoxlist.jsp
<%@ taglib prefix="s" uri="/struts-tags" %> <html> <head> </head> <body> <h1>Struts 2 multiple check boxes example</h1> <s:form action="resultAction" namespace="/"> <h4> <s:checkboxlist label="What's your favor color" list="colors" name="yourColor" value="defaultColor" /> </h4> <s:submit value="submit" name="submit" /> </s:form> </body> </html>
result.jsp
<%@ taglib prefix="s" uri="/struts-tags" %> <html> <body> <h1>Struts 2 multiple check boxes example</h1> <h4> Favor colors : <s:property value="yourColor"/> </h4> </body> </html>
3. struts.xml
Link all together ~
<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE struts PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN" "http://struts.apache.org/dtds/struts-2.0.dtd"> <struts> <constant name="struts.devMode" value="true" /> <package name="default" namespace="/" extends="struts-default"> <action name="checkBoxListAction" class="com.mkyong.common.action.CheckBoxListAction" method="display"> <result name="none">pages/checkBoxlist.jsp</result> </action> <action name="resultAction" class="com.mkyong.common.action.CheckBoxListAction"> <result name="success">pages/result.jsp</result> </action> </package> </struts>
5. Demo
http://localhost:8080/Struts2Example/checkBoxListAction.action

http://localhost:8080/Struts2Example/resultAction.action


error:
org.apache.jasper.JasperException: tag ‘checkboxlist’, field ‘list’, name ‘yourColors’: The requested list key ‘colors’ could not be resolved as a collection/array/map/enumeration/iterator type. Example: people or people.{name} – [unknown location]
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:527)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:419)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:73)
root cause
tag ‘checkboxlist’, field ‘list’, name ‘yourColors’: The requested list key ‘colors’ could not be resolved as a collection/array/map/enumeration/iterator type. Example: people or people.{name} – [unknown location]
org.apache.struts2.components.Component.fieldError(Component.java:230)
org.apache.struts2.components.Component.findValue(Component.java:351)
org.apache.struts2.components.ListUIBean.evaluateExtraParams(ListUIBean.java:80)
org.apache.struts2.components.UIBean.evaluateParams(UIBean.java:856)
org.apache.struts2.components.UIBean.end(UIBean.java:510)
org.apache.struts2.views.jsp.ComponentTagSupport.doEndTag(ComponentTagSupport.java:42)
org.apache.jsp.checkbox_jsp._jspx_meth_s_005fcheckboxlist_005f0(checkbox_jsp.java:148)
org.apache.jsp.checkbox_jsp._jspx_meth_s_005fform_005f0(checkbox_jsp.java:109)
org.apache.jsp.checkbox_jsp._jspService(checkbox_jsp.java:72)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:377)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:73)
note The full stack trace of the root cause is available in the Apache Tomcat/6.0.24 logs.
every example display same error whats problem please solve ?
just change the name “yourColors” to all lowercase “yourcolors” this will solve your issues.
Its still not working..showing the same error