Querying Connector Metadata

            //  Aim - Query the connector to determine what connection properties it  
 //  requires and what are the metadata of the respective properties.

 //  The Workflow
 //  - Get the connection factory (see above).
 //  - Get a connection spec.
 //  - Get the metadata for the connection spec
 //  From the outside:
 IConnectionSpecMetaData connectionSpecMetaData = cs.getMetaData();

 Set connectionPropertiesNames = csmd.retrieveAllConnectionPropertiesNames();
 Iterator iter = connectionPropertiesNames.iterator();

 while (iter.hasNext()) {
  //  Save the name.
  IConnectionProperty currentProperty =
   connectionSpecMetaData.getConnectionProperty((String) iter.next());

  Boolean isMandatory currentProperty.isMandatory() Object defaultValue =
   currentProperty.defaultValue();
  // Etc…
 }
 //  From the inside:
 //  Here is a possible implementation for a certain connection  
 //  property interface. Its structure:
 public IPrimitive getMetadata() {
  return m_metadata;
 }
 //  Whether it is a user level or a system level property:
 //  - Things like serve name, port, system id, etc. are system 
 //    level properties.
 //  - Things like user name, password, language, etc are user 
 //    level properties.
 public String getType() {
  return m_type;
  //  This is a possible implementation for connection spec metadata
  //  interface.
  public class JDBCConnectionSpecMetaData
   implements IConnectionSpecMetaData {
   public JDBCConnectionSpecMetaData() {
   }

   private static Map m_allProperties;
   static {
    m_allProperties = new HashMap();
    IString metadata = new StringPrimitive(-1, -1, "");

    m_allProperties.put(
     "username",
     new JDBCConnectionProperty(
      metadata,
      IConnectionProperty.CONNECTION_PROPERTY_TYPE_USER,
      false));
    m_allProperties.put(
     "password",
     new JDBCConnectionProperty(
      metadata,
      IConnectionProperty.CONNECTION_PROPERTY_TYPE_USER,
      false));
    m_allProperties.put(
     "url",
     new JDBCConnectionProperty(
      metadata,
      IConnectionProperty.CONNECTION_PROPERTY_TYPE_SYSTEM,
      false));
   }
   //  To return all the possible connection properties.
   public Set getAllConnectionProperties() {
    return new HashMap(m_allProperties).entrySet();
   }
   //  To return a set of all possible connection property names.
   public Set retrieveAllConnectionPropertiesNames() {
    return new HashMap(m_allProperties).keySet();
   }

   public IConnectionProperty getConnectionProperty(String propertyName) {
    return (IConnectionProperty) m_allProperties.get(propertyName);
   }

  }
 }
 //  Some properties only accept a predefined set of values.
 public Set getValidValues() {
  return null;
 }
 //  To return whether or not the property is mandatory.
 public boolean getIsMandatory() {
  return false;
 }
 //  To return a default value for this connection property, if any.
 public Object getDefaultValue() {
  return null;
 }