IOS Introduction
Swift UI Label
Swift UI Button
Swift UI Text Field
Swift UI Slider
Swift UI Switch
Swift UI Stepper
Swift UI Date Picker
Swift UI Segmented Control
Table View
Collection Views
iOS Content View
iOS View Controllers
iOS Bar interface
iOS Navigation interface
iOS Architect Pattern
iOS Libraries
iOS Web request and parsing
iOS user defaults
iOS Coredata and database

Pesist object model

Understanding Things Going On

A persistent object continues to exist and retains its data over the course of the process it creates. In contrast, a passing object exists only in the memory of its creation; when that process ends, the temporary object ceases to exist.

He builds an object of a class that can persist as a passing object. The object is made persistent during the transaction when it is given storage space in an integrated storage area; see Making Something Go On. When you make a transaction in which you make a persistent item, that item is stored in an integrated database; something can be achieved through other transactions.

Continuous objects reside in an integrated Objectivity / DB database. During the transaction, you receive a persistent discovery of a Java object that indicates the location of an object stored in an integrated database. You are cheating the Java object in the app memory. Any changes or deletions are only available in the app memory until you view or make a transaction; then, the changes are recorded in the integrated database and visible in other transactions.

Persistent Classes

Only in the case of resilient classes can they be persistent. The purpose of Java includes powerful classes for various objects, such as continuous collections. The Java Objectivity function can define any number of classes that can persist. See Chapter 10, Defining Persistent Classes.


The following persistent behavior is found in all persistent objects:

You can build links to something that persists; see Chapter 15, Creating and Following Links.

You can find a persistent object within the compiled data; see Scanning the Federated Database.

You can give the object a persistent name, allowing you to look at it with that name; see Obtaining an Object by a Wide Name.

If you attempt to apply one of these features to a compliant component, the NonPersistentClassException is thrown.