title: Android ContentProvider getType() called when and why
body: <p>I put a log in getType() method it never gets printed. I am using the Notepad sample code. Please explain the 1st line of Java doc comment. Returning null from getType() is also working fine.
  What is the purpose of getType() method?</p>
  
  <pre><code>    /**
   * This is called when a client calls {@link android.content.ContentResolver#getType(Uri)}.
   * Returns the MIME data type of the URI given as a parameter.
   * 
   * @param uri The URI whose MIME type is desired.
   * @return The MIME type of the URI.
   * @throws IllegalArgumentException if the incoming URI pattern is invalid.
   */
  @Override
  public String getType(Uri uri)
  {
      Log.d("Suparna", "******getType()");
      /*switch(uriMatcher.match(uri))
      {
      // ---get all books---
      case BOOK_DETAILS:
          return Book.Book_Details.CONTENT_TYPE;
          // ---get a particular book---
      case BOOK_DETAILS_ID:
          return Book.Book_Details.CONTENT_ITEM_TYPE;
      default:
          throw new IllegalArgumentException("Unsupported URI: " + uri);
      }*/
      return null;
  }
  </code></pre>