Re: selectOneMenu and selectItem sample

Aneesha Govil Thu, 21 Sep 2006 05:23:07 -0700

Hi,

I am using navigation to load another JSP according to what was selected in the drop down. However in the getPageToDisplay method below, the selectedItem is null and there is a null pointer exception. So I get an error "Error calling action method of component...".

Does anyone have any idea how to fix this?

Thanks.

The Form bean is below:

import java.util.ArrayList;
import java.util.List;

import javax.faces.model.SelectItem;

public class TableForm {
    private List<SelectItem> tables = new ArrayList<SelectItem>();
    public TableForm() {
        tables.add(new SelectItem("Table 1", "1"));
        tables.add(new SelectItem("Table 2", "2"));
    }

    private SelectItem selectedTable = null;

    public SelectItem getSelectedTable() {
        return selectedTable;
    }

    public void setSelectedTable(SelectItem selectedTable) {
        this.selectedTable = selectedTable;
    }

    public List getTables() {
        return tables;
    }

    public String getPagetoDisplay() {

        if (selectedTable.getLabel().equals("1")) { // Null pointer exception here
            System.out.println("Inside 1");
            return "displaytable1";
        }
        else if (selectedTable.getLabel().equals("2")) {
            return "displaytable2";
        }
        else return "";
    }
}

The JSP file is:

<%@ taglib uri="http://java.sun.com/jsf/core" prefix="f" %>
<%@ taglib uri="http://java.sun.com/jsf/html" prefix="h" %>
<f:view>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
<HEAD><TITLE>Plain Table</TITLE>
<LINK REL="STYLESHEET"
      HREF="">      TYPE="text/css">
</HEAD>
<BODY>
<CENTER>
<TABLE BORDER=5>
<TR><TH CLASS="TITLE">Plain Table Demo</TH></TR>
</TABLE>
<P>
<h:form>
    <h:selectOneMenu required="true">
         <f:selectItems value="#{tableform.tables}"/>
    </h:selectOneMenu>
    <h:commandButton value="Submit" immediate="true" action="" }"/>
</h:form>
</CENTER></BODY></HTML>
</f:view>

Re: selectOneMenu and selectItem sample

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