JSF中arrayList的jsf-arrayList

Question

I have a ArrayList of ArrayList - I declare it in this way:

ArrayList<ArrayList<String>> queryResult=new ArrayList<ArrayList<String>>();

Then I add a new element to array like this:

for(int i=1;i<colNumber;i++)
{
    queryResult.add(new ArrayList<String>(20));
}

after that I add a value to elements of array:

while(r.next())
{   
    for(int i=0;i<colNumber;i++)
    {
        queryResult.get(i).add(r.getString(i));  
    }     
}

But when I try to use it in DataTable tag I see nothing :(

<h:dataTable value="#{polaczenieSQL.queryResult}" var="w">
          <h:column>
             <f:facet name="head">typ</f:facet>
             #{w[0]}
          </h:column>

What I am doing wrong? How should I use this array in JSF?

Ps this is my faces.config:

     <managed-property>
        <property-name>queryResult</property-name>
        <property-class>java.util.ArrayList</property-class>
        <list-entries></list-entries>
     </managed-property>

---

I found first problem:

r.getString(i)

I added a

System.out.print("something")

after a loop but it doesn't want to print.

When I change a variable 'i' and type for example: 4 I see "something" on my console . Variable 'colNumber' is set to 5 (but my sql table have 7 columns and I use "select * from mytable" so I dont think that is a counter problem ).

Answer 1

If you want to print all the values in the inner list you should do as following:

<h:dataTable value="#{polaczenieSQL.queryResult}" var="w">
      <h:column>
         <f:facet name="head">typ</f:facet>
         #{w[0]} <!--will print the first element in the inner list-->
      </h:column>
      <h:column>
         <f:facet name="head">typ</f:facet>
         #{w[2]} <!--will print the second element in the inner list-->
      </h:column>
      ...
      <h:column>
         <f:facet name="head">typ</f:facet>
         #{w[n]} <!--will print the nth element in the inner list-->
      </h:column>
</h:dataTable>

so basically if you want to print all the values of a inner list you can use the following style:

<ui:repeat value="#{activeUser.listInList}" var="innerList">
    <ui:repeat value="#{innerList}" var="innerListValue">
        #{innerListValue}
    </ui:repeat>
</ui:repeat>

And about exception swallowing, you should throw an exception whenever you catch one unless you know exactly what you are missing.