Fields, Variables, Attributes, and Properties: What\'s the Difference in Java POJOs?

Understanding the Terminology: Field, Variable, Attribute, and Property

Java POJOs (Plain Old Java Objects) often utilize getters and setters to access internal private variables. While it's not uncommon to use the terms "field," "variable," "attribute," and "property" interchangeably, there are subtle distinctions.

Field

According to the official Java glossary, a field represents a data member of a class. It typically stores the internal state of an object and is not static by default.

Property

A property, as defined by the glossary, denotes a characteristic of an object that users can modify. This could include visual aspects like the background color of a window.

Attribute

The term "attribute" is not explicitly listed in the Java glossary. However, it often refers to a general characteristic or quality of an object that is not specifically defined as a field.

Variable

A variable is a named data item that holds a value. It has a defined type (e.g., integer, string) and a scope (e.g., local, instance). Variables can be used both within methods and to represent object properties.

Distinction in Persistence

When persisting Java POJOs, they typically become entities within a data store (e.g., database). In this context:

• Fields refer to the physical storage representation within the database, often mapped to specific columns.
• Properties remain accessible to users and represent the modifiable characteristics of the persisted entity.

Therefore, it's appropriate to use "field" and "property" when referring to internal and external aspects of a persistent entity, respectively.

The above is the detailed content of Fields, Variables, Attributes, and Properties: What\'s the Difference in Java POJOs?. For more information, please follow other related articles on the PHP Chinese website!