LazyList pattern error...

[Timothy Sam]

Hi, following the instructions in this link...

http://wiki.apache.org/struts/StrutsCatalogLazyList


I was able to poppulate the member of type ArrayList in my bean... However, I could no longer retrieve the value using logic iterate... I do it like this...

<logic:iterate name="applicantFormBean" property="employmentHistory" id="employment" indexId="ctr">
 xxx
 <br/>
</logic:iterate> 

and it gives the error (the one in bold letters)

HTTP Status 500 -

--------------------------------------------------------------------------------

type Exception report

message

description The server encountered an internal error () that prevented it from fulfilling this request.

exception

org.apache.jasper.JasperException: Exception in JSP: /WEB-INF/pages/success.jsp:78

75:
76: Employment:
77:
78: <logic:iterate name="applicantFormBean" property="employmentHistory" id="employment" indexId="ctr">
79: a
80: <br/>
81: </logic:iterate>


Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:504)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:375)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.struts.action.RequestProcessor.doForward(RequestProcessor.java:1056)
org.apache.struts.action.RequestProcessor.processForwardConfig(RequestProcessor.java:388)
org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:231)
org.apache.struts.action.ActionServlet.process(ActionServlet.java:1164)
org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:415)
javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)


root cause

javax.servlet.ServletException: No getter method for property employmentHistory of bean applicantFormBean
org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageContextImpl.java:858)
org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:791)
org.apache.jsp.WEB_002dINF.pages.success_jsp._jspService(success_jsp.java:231)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:332)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.struts.action.RequestProcessor.doForward(RequestProcessor.java:1056)
org.apache.struts.action.RequestProcessor.processForwardConfig(RequestProcessor.java:388)
org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:231)
org.apache.struts.action.ActionServlet.process(ActionServlet.java:1164)
org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:415)
javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)


root cause

javax.servlet.jsp.JspException: No getter method for property employmentHistory of bean applicantFormBean
org.apache.struts.taglib.TagUtils.lookup(TagUtils.java:1031)
org.apache.struts.taglib.logic.IterateTag.doStartTag(IterateTag.java:234)
org.apache.jsp.WEB_002dINF.pages.success_jsp._jspService(success_jsp.java:173)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:332)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.struts.action.RequestProcessor.doForward(RequestProcessor.java:1056)
org.apache.struts.action.RequestProcessor.processForwardConfig(RequestProcessor.java:388)
org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:231)
org.apache.struts.action.ActionServlet.process(ActionServlet.java:1164)
org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:415)
javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)


note The full stack trace of the root cause is available in the Apache Tomcat/5.5.17 logs.


--------------------------------------------------------------------------------

Apache Tomcat/5.5.17

I'm quite sure I provided a getter method... Here's what the ApplicantFormBean looks like with the two getters for employmentHistory highlighted in bold letters...

package beans;
 
import java.util.ArrayList;
 
import javax.servlet.http.HttpServletRequest;
 
import org.apache.struts.action.ActionErrors;
import org.apache.struts.action.ActionMapping;
 
public class ApplicantFormBean extends org.apache.struts.validator.ValidatorForm
{
    UserFormBean user;
    NameFormBean name;
    PersonalInfoFormBean personalInfo;
    PictureFormBean picture;
    PassportFormBean passport;
    ParentFormBean parent;
    BenificiaryFormBean benificiary;
    SkillsFormBean skills;
    EducationFormBean education;
    //EmploymentFormBean employment;
    ApplicationInfoFormBean applicationInfo;
ArrayList<EmploymentFormBean> employmentHistory;
    
    public ApplicantFormBean()
    {
    System.out.println("Instantiating ApplicantFormBean");
    user = new UserFormBean();
        name = new NameFormBean();
        personalInfo = new PersonalInfoFormBean();
        picture = new PictureFormBean();
        passport = new PassportFormBean();
        parent = new ParentFormBean();
        benificiary = new BenificiaryFormBean();
        skills = new SkillsFormBean();
        education = new EducationFormBean();
        //employment = new EmploymentFormBean();
        applicationInfo = new ApplicationInfoFormBean();
        employmentHistory = new ArrayList<EmploymentFormBean>();
    }
    
    public NameFormBean getName() 
    {
return name;
}
    
public void setName(NameFormBean name) 
{
this.name = name;
}

public PassportFormBean getPassport() 
{
return passport;
}

public void setPassport(PassportFormBean passport) 
{
this.passport = passport;
}

public UserFormBean getUser() 
{
return user;
}

public void setUser(UserFormBean user) 
{
this.user = user;
}
 
public PersonalInfoFormBean getPersonalInfo() 
{
return personalInfo;
}
 
public void setPersonalInfo(PersonalInfoFormBean personalInfo) 
{
this.personalInfo = personalInfo;
}

public ApplicationInfoFormBean getApplicationInfo() 
{
return applicationInfo;
}
 
public void setApplicationInfo(ApplicationInfoFormBean applicationInfo) 
{
this.applicationInfo = applicationInfo;
}
 
public BenificiaryFormBean getBenificiary() 
{
return benificiary;
}
 
public void setBenificiary(BenificiaryFormBean benificiary) 
{
this.benificiary = benificiary;
}
 
public EducationFormBean getEducation() 
{
return education;
}
 

public void setEducation(EducationFormBean education) 
{
this.education = education;
}
 
/*
public EmploymentFormBean getEmployment() 
{
return employment;
}
 
public void setEmployment(EmploymentFormBean employment) 
{
this.employment = employment;
}
    */

public ParentFormBean getParent() 
{
return parent;
}
 
public void setParent(ParentFormBean parent) 
{
this.parent = parent;
}
 
public PictureFormBean getPicture() 
{
return picture;
}
 
public void setPicture(PictureFormBean picture) 
{
this.picture = picture;
}
 
public SkillsFormBean getSkills() 
{
return skills;
}
 
public void setSkills(SkillsFormBean skills) 
{
this.skills = skills;
}

[B]
public ArrayList<EmploymentFormBean> getEmploymentHistory() 
{
return employmentHistory;
}
        [/B]


    public void reset(ActionMapping actionMapping, HttpServletRequest request) 
    {
    }
 
    public ActionErrors validate(ActionMapping actionMapping, HttpServletRequest request) 
    {
        return null;
    }
    
    public void poppulateEmploymentHistory(ArrayList<EmploymentFormBean> employmentHistory)
    {
        this.employmentHistory.addAll(employmentHistory);
    }
    
    public void setEmploymentHistory(EmploymentFormBean employment)
    {
    employmentHistory.add(employment);
    }
    
    [B]
    public EmploymentFormBean getEmploymentHistory(int index)
    {
    while ( index >= employmentHistory.size() )
    {
    employmentHistory.add( new EmploymentFormBean() );
    }
    
    return employmentHistory.get(index);
    }
    [/B]
 
}

I hope you could help me with this... Thanks!

[Brent Sterling]

Sometimes I think I understand how indexed properties work, but every time I use them I have to step back and think about it. I seem to recall having problems with having get and set method with the same name where the parameter and return types did not match. Instead of having overloaded versions of getEmploymentHistory, I would use unique names such as this:

public ArrayList<EmploymentFormBean> getEmploymentHistoryList()
public EmploymentFormBean getEmploymentHistoryItem(int index)

I would also remove the method setEmploymentHistory. Struts will not call this method, but if you need to from your code then rename it addEmploymentHistory. I am not sure that will solve the problem, but it seems worth a try.

- Brent

[Timothy Sam]

Do I have to name my members appopriately, based on your suggestion? So if I rename my methods as


public ArrayList<EmploymentFormBean> getEmploymentHistoryList()
public EmploymentFormBean getEmploymentHistoryItem(int index)


I also have to rename my members to employmentHistoryList and employmentHistoryItem? Thanks for your reply!

[Brent Sterling]

I am not sure that you have to name your methods per my suggestion, but that is a convention that I have used. I remember working with another developer to track down an issue, and it was related to having mismatched get and set methods. You have a getEmploymentHistory that returns ArrayList<EmploymentFormBean> and a setEmploymentHistory method that takes an EmploymentFormBean as a parameter. At a minimum this violates the spirit of Java Bean properties.

I am not sure if the following example is 100% correct (plus I don't know the properties of your EmploymentFormBean class). The bean:write example does not submit back to the server, so you can just use the id value of the iterate tag. The html:text example uses a scriptlet and the html:checkbox uses the indexed property.

<logic:iterate
        name="applicantFormBean"
        property="employmentHistoryList"
        id="employmentBean"
        indexId="ctr">
    <bean:write name="employmentBean" property="company" />
    <html:text property='<%= "employmentHistoryItem[" + ctr + "].salary" %>' />
    <html:checkbox name="employmentHistoryItem" property="notProfit" indexed="true" />
</logic:iterate>
 

- Brent