Let's define a couple of entities to use in our example. We will create an entity Todo to manage todos. A simple example is shown as follows:
@Entity public class Todo { @Id @GeneratedValue(strategy = GenerationType.AUTO) private Long id; @ManyToOne(fetch = FetchType.LAZY) @JoinColumn(name = "userid") private User user; private String title; private String description; private Date targetDate; private boolean isDone; public Todo() {// Make JPA Happy } }
Important things to note are as follows:
- Todo has a title, a description, a target date, and a completion indicator (isDone). JPA needs a constructor.
- @Entity: The annotation specifies that the class is an entity.
- @Id: Specifies that ID is the primary key of the entity.
- @GeneratedValue(strategy ...
