private void addImport(XmlSchema schema, String ns) {
if (!ns.equals(schema.getTargetNamespace())
&& !ns.equals(WSDLConstants.NS_SCHEMA_XSD)
&& !isExistImport(schema, ns)) {
XmlSchemaImport is = new XmlSchemaImport(schema);
is.setNamespace(ns);
if (this.schemaLocationMapping.get(ns) != null) {
is.setSchemaLocation(this.schemaLocationMapping.get(ns));
}
if (!schema.getItems().contains(is)) {
schema.getItems().add(is);
}
}