Null Pointer em Bean do RichDataTable

package br.com.sigga.mb;

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

import javax.el.MethodExpression;
import javax.el.ValueExpression;
import javax.faces.component.html.HtmlForm;
import javax.faces.component.html.HtmlOutputText;
import javax.faces.component.html.HtmlPanelGroup;
import javax.faces.context.FacesContext;

import org.ajax4jsf.component.html.HtmlAjaxCommandButton;
import org.ajax4jsf.component.html.HtmlAjaxSupport;
import org.richfaces.component.html.HtmlColumn;
import org.richfaces.component.html.HtmlDataTable;


public class DynamicDataTable {
	// Init
	// --------------------------------------------------------------------------------------

	private static List<List<String>> dynamicList; // Simulate fake DB.
	private static String[] dynamicHeaders; // Optional.
	HtmlDataTable dynamicDataTable;
	private List<String> item;
	
	// Actions
	// -----------------------------------------------------------------------------------

	private void loadDynamicList() {

		// Set headers (optional).
		dynamicHeaders = new String[] { "ID", "Name", "Value" };

		// Set rows. This is a stub example, just do your dynamic thing.
		dynamicList = new ArrayList<List<String>>();
		dynamicList.add(Arrays
				.asList(new String[] { "ID1", "Name1", "Value1" }));
		dynamicList.add(Arrays
				.asList(new String[] { "ID2", "Name2", "Value2" }));
		dynamicList.add(Arrays
				.asList(new String[] { "ID3", "Name3", "Value3" }));
		dynamicList.add(Arrays
				.asList(new String[] { "ID4", "Name4", "Value4" }));
		dynamicList.add(Arrays
				.asList(new String[] { "ID5", "Name5", "Value5" }));
	}

	private void populateDynamicDataTable() {

		HtmlForm form = new HtmlForm();
		
		// Create <h:dataTable value="#{myBean.dynamicList}" var="dynamicItem">.
		dynamicDataTable = new HtmlDataTable();
		dynamicDataTable.setId("dataTable");
		dynamicDataTable.setValueExpression("value", createValueExpression(
				"#{dynamicDataTable.dynamicList}", List.class));
		dynamicDataTable.setVar("dynamicItem");
		
		//dynamicDataTable.getChildren().add(createAjaxSuporte());
		dynamicDataTable.setRowClasses("row1, row2" );
		//dynamicDataTable.setOnRowClick("#{dynamicDataTable.test}");
		
		// Iterate over columns.
		for (int i = 0; i < dynamicList.get(0).size(); i++) {

			// Create <h:column>.
			HtmlColumn column = new HtmlColumn();

			// Create <h:outputText value="dynamicHeaders[i]"> for <f:facet
			// name="header"> of column.
			HtmlOutputText header = new HtmlOutputText();
			header.setValue(dynamicHeaders[i]);
			column.setHeader(header);

			// Create <h:outputText value="#{dynamicItem[" + i + "]}"> for the
			// body of column.
			HtmlOutputText output = new HtmlOutputText();
			output.setValueExpression("value", createValueExpression(
					"#{dynamicItem[" + i + "]}", String.class));
			column.getChildren().add(output);			

			dynamicDataTable.getChildren().add(column);
		}
		HtmlColumn column = new HtmlColumn();
		
		HtmlAjaxCommandButton commandButton = new HtmlAjaxCommandButton();
		String value = "CLICK";
		commandButton.setValue(value);
		commandButton.setActionExpression(createMethodExpression("#{dynamicDataTable.getSelected}", String.class));		
	
		//HtmlActionParameter parameter = new HtmlActionParameter();
		//parameter.setValue("#{currentRow}");
		//commandButton.getChildren().add(parameter);
		
		column.getChildren().add(commandButton);
		
		
		dynamicDataTable.getChildren().add(column);
		//dynamicDataTable.getChildren().add(createAjaxSuporte());
	}

	// Getters
	// -----------------------------------------------------------------------------------

	public List<String> getItem() {
		return item;
	}

	public void setItem(List<String> item) {
		this.item = item;
	}

	public List<List<String>> getDynamicList() {
		return dynamicList;
	}

	private ValueExpression createValueExpression(String valueExpression,
			Class<?> valueType) {
		FacesContext facesContext = FacesContext.getCurrentInstance();
		return facesContext.getApplication().getExpressionFactory()
				.createValueExpression(facesContext.getELContext(),
						valueExpression, valueType);
	}

    private MethodExpression createMethodExpression(String actionExpression, Class<?> returnType) {
        FacesContext facesContext = FacesContext.getCurrentInstance();
        return facesContext.getApplication().getExpressionFactory().createMethodExpression(
            facesContext.getELContext(), actionExpression, returnType, new Class[0]);
    }

    public String getSelected() {
		String x = dynamicDataTable.getRowData().toString();
		System.out.println(x);
		return "";
	}
}