public static void copy(IMetaStore from, IMetaStore to, boolean overwrite)
      throws MetaStoreException {

    // get all of the namespace in the "from" metastore
    List<String> namespaces = from.getNamespaces();
    for (String namespace : namespaces) {
      // create the sme namespace in the "to" metastore
      try {
        to.createNamespace(namespace);
      } catch (MetaStoreNamespaceExistsException e) {
        // already there
      }
      // get all of the element types defined in this namespace
      List<IMetaStoreElementType> elementTypes = from.getElementTypes(namespace);
      for (IMetaStoreElementType elementType : elementTypes) {
        // See if it's already there
        IMetaStoreElementType existingType =
            to.getElementTypeByName(namespace, elementType.getName());
        if (existingType != null) {
          if (overwrite) {
            // we looked it up by name, but need to update it by id
            elementType.setId(existingType.getId());
            to.updateElementType(namespace, elementType);
          } else {
            elementType = existingType;
          }
        } else {
          // create the elementType in the "to" metastore
          to.createElementType(namespace, elementType);
        }

        // get all of the elements defined for this type
        List<IMetaStoreElement> elements = from.getElements(namespace, elementType);
        for (IMetaStoreElement element : elements) {
          IMetaStoreElement existingElement =
              to.getElementByName(namespace, elementType, element.getName());
          if (existingElement != null) {
            element.setId(existingElement.getId());
            if (overwrite) {
              to.updateElement(namespace, elementType, existingElement.getId(), element);
            }
          } else {
            to.createElement(namespace, elementType, element);
          }
        }
      }
    }
  }
  @Test
  public void testIDMigration() throws Exception {

    String namespace = "custom";
    String stepName = "Step Name";
    String elementName = "migration";
    String hostName = "Host Name";
    String fieldMappings = "Field Mappings";
    String sourceFieldName = "Source Field Name";
    String targetFieldName = "Target Field Name";
    String parameterName = "Parameter Name";

    IMetaStore metaStore = new MemoryMetaStore();

    MetaStoreFactory<MyMigrationElement> factory =
        new MetaStoreFactory<MyMigrationElement>(MyMigrationElement.class, metaStore, namespace);

    if (!metaStore.namespaceExists(namespace)) {
      metaStore.createNamespace(namespace);
    }

    MetaStoreElementType elementTypeAnnotation =
        MyMigrationElement.class.getAnnotation(MetaStoreElementType.class);

    // Make sure the element type exists...
    IMetaStoreElementType elementType =
        metaStore.getElementTypeByName(namespace, elementTypeAnnotation.name());
    if (elementType == null) {
      elementType = metaStore.newElementType(namespace);
      elementType.setName(elementTypeAnnotation.name());
      elementType.setDescription(elementTypeAnnotation.description());
      metaStore.createElementType(namespace, elementType);
    }

    // Create an element with the old keys we want to migrate
    IMetaStoreElement element = metaStore.newElement();
    element.setName(elementName);
    element.setElementType(elementType);

    element.addChild(metaStore.newAttribute("stepName", stepName));
    element.addChild(metaStore.newAttribute("hostname", hostName));
    element.addChild(metaStore.newAttribute("fieldMappings", fieldMappings));
    element.addChild(metaStore.newAttribute("sourceFieldName", sourceFieldName));
    element.addChild(metaStore.newAttribute("targetFieldName", targetFieldName));
    element.addChild(metaStore.newAttribute("parameterName", parameterName));

    metaStore.createElement(namespace, elementType, element);

    MyMigrationElement loadedElement = factory.loadElement(elementName);

    assertNotNull(loadedElement);
    assertEquals(loadedElement.getStepName(), stepName);
    assertEquals(loadedElement.getHostname(), hostName);
    assertEquals(loadedElement.getFieldMappings(), fieldMappings);
    assertEquals(loadedElement.getSourceFieldName(), sourceFieldName);
    assertEquals(loadedElement.getTargetFieldName(), targetFieldName);
    assertEquals(loadedElement.getParameterName(), parameterName);

    // Test the variation of the step name id
    element = metaStore.newElement();
    element.setName(elementName);
    element.setElementType(elementType);

    element.addChild(metaStore.newAttribute("stepname", stepName));

    metaStore.createElement(namespace, elementType, element);

    loadedElement = factory.loadElement(elementName);

    assertNotNull(loadedElement);
    assertEquals(loadedElement.getStepname(), stepName);
  }
 /**
  * Create the specified namespace if it doesn't exist.
  *
  * @param metaStore
  * @param namespace
  * @throws MetaStoreException
  */
 public static void verifyNamespaceCreated(IMetaStore metaStore, String namespace)
     throws MetaStoreException {
   if (!metaStore.namespaceExists(namespace)) {
     metaStore.createNamespace(namespace);
   }
 }