smart gwt required xml file structure - smartgwt

Question

code is working properly.but i am not able to display the final data which is from "setDataURL("ds/test_data/employees.data.xml".so tel me where shud i create dis file and how to create.
package com.smartgwt.sample.showcase.client;
import com.smartgwt.client.data.DataSource;
import com.smartgwt.client.data.fields.DataSourceFloatField;
import com.smartgwt.client.data.fields.DataSourceIntegerField;
import com.smartgwt.client.data.fields.DataSourceTextField;
import com.smartgwt.client.widgets.Canvas;
import com.smartgwt.client.widgets.grid.CellFormatter;
import com.smartgwt.client.widgets.grid.ListGridRecord;
import com.smartgwt.client.widgets.tree.TreeGrid;
import com.smartgwt.client.widgets.tree.TreeGridField;
import com.google.gwt.i18n.client.NumberFormat;
import com.smartgwt.sample.showcase.shared.FieldVerifier;
import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.core.client.GWT;
import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.event.dom.client.KeyCodes;
import com.google.gwt.event.dom.client.KeyUpEvent;
import com.google.gwt.event.dom.client.KeyUpHandler;
import com.google.gwt.user.client.rpc.AsyncCallback;
import com.google.gwt.user.client.ui.Button;
import com.google.gwt.user.client.ui.DialogBox;
import com.google.gwt.user.client.ui.HTML;
import com.google.gwt.user.client.ui.Label;
import com.google.gwt.user.client.ui.RootPanel;
import com.google.gwt.user.client.ui.TextBox;
import com.google.gwt.user.client.ui.VerticalPanel;
/**
* Entry point classes define <code>onModuleLoad()</code>.
*/
public class Showcase implements EntryPoint {
/**
* The message displayed to the user when the server cannot be reached or
* returns an error.
*/
private static final String SERVER_ERROR = "An error occurred while "
+ "attempting to contact the server. Please check your network "
+ "connection and try again.";
/**
* Create a remote service proxy to talk to the server-side Greeting service.
*/
private final GreetingServiceAsync greetingService = GWT
.create(GreetingService.class);
/**
* This is the entry point method.
*/
public void onModuleLoad() {
RootPanel.get().add(getViewPanel());
}
public Canvas getViewPanel() {
EmployeeXmlDS employeesDS = EmployeeXmlDS.getInstance();
TreeGrid treeGrid = new TreeGrid();
treeGrid.setCanEdit(true);
treeGrid.setLoadDataOnDemand(false);
treeGrid.setWidth(500);
treeGrid.setHeight(400);
treeGrid.setDataSource(employeesDS);
treeGrid.setNodeIcon("icons/16/person.png");
treeGrid.setFolderIcon("icons/16/person.png");
treeGrid.setShowOpenIcons(false);
treeGrid.setShowDropIcons(false);
treeGrid.setClosedIconSuffix("");
treeGrid.setAutoFetchData(true);
TreeGridField nameField = new TreeGridField("Name");
TreeGridField jobField = new TreeGridField("Job");
TreeGridField salaryField = new TreeGridField("Salary");
salaryField.setCellFormatter(new CellFormatter() {
public String format(Object value, ListGridRecord record, int rowNum, int colNum) {
if (value != null) {
NumberFormat nf = NumberFormat.getFormat("#,##0");
try {
return "$" + nf.format(((Number) value).longValue());
} catch (Exception e) {
return value.toString();
}
} else {
return null;
}
}
});
treeGrid.setFields(nameField, jobField, salaryField);
return treeGrid;
}
}
class EmployeeXmlDS extends DataSource {
private static EmployeeXmlDS instance = null;
public static EmployeeXmlDS getInstance() {
if (instance == null) {
instance = new EmployeeXmlDS("employeesDS");
}
return instance;
}
public EmployeeXmlDS(String id) {
setID(id);
setTitleField("Name");
setRecordXPath("/List/employee");
DataSourceTextField nameField = new DataSourceTextField("Name", "Name", 128);
DataSourceIntegerField employeeIdField = new DataSourceIntegerField("EmployeeId", "Employee ID");
employeeIdField.setPrimaryKey(true);
employeeIdField.setRequired(true);
DataSourceIntegerField reportsToField = new DataSourceIntegerField("ReportsTo", "Manager");
reportsToField.setRequired(true);
reportsToField.setForeignKey(id + ".EmployeeId");
reportsToField.setRootValue("1");
DataSourceTextField jobField = new DataSourceTextField("Job", "Title", 128);
DataSourceTextField emailField = new DataSourceTextField("Email", "Email", 128);
DataSourceTextField statusField = new DataSourceTextField("EmployeeStatus", "Status", 40);
DataSourceFloatField salaryField = new DataSourceFloatField("Salary", "Salary");
DataSourceTextField orgField = new DataSourceTextField("OrgUnit", "Org Unit", 128);
DataSourceTextField genderField = new DataSourceTextField("Gender", "Gender", 7);
genderField.setValueMap("male", "female");
DataSourceTextField maritalStatusField = new DataSourceTextField("MaritalStatus",
"Marital Status", 10);
setFields(nameField, employeeIdField, reportsToField, jobField, emailField, statusField,
salaryField, orgField, genderField, maritalStatusField);
setDataURL("ds/test_data/employees.data.xml");
setClientOnly(true);
}
}