29.3.1. 实体类

通常，JPA实体类被定义到一个persistence.xml文件，在Spring Boot中，这个文件被’实体扫描’取代。默认情况，Spring Boot会查找主配置类（被@EnableAutoConfiguration或@SpringBootApplication注解的类）下的所有包。

任何被@Entity，@Embeddable或@MappedSuperclass注解的类都将被考虑，一个普通的实体类看起来像这样：

  1. package com.example.myapp.domain;
  3. import java.io.Serializable;
  4. import javax.persistence.*;
  6. @Entity
  7. public class City implements Serializable {
  9.     @Id
  10.     @GeneratedValue
  11.     private Long id;
  13.     @Column(nullable = false)
  14.     private String name;
  16.     @Column(nullable = false)
  17.     private String state;
  19.     // ... additional members, often include @OneToMany mappings
  21.     protected City() {
  22.         // no-args constructor required by JPA spec
  23.         // this one is protected since it shouldn't be used directly
  24.     }
  26.     public City(String name, String state) {
  27.         this.name = name;
  28.         this.country = country;
  29.     }
  31.     public String getName() {
  32.         return this.name;
  33.     }
  35.     public String getState() {
  36.         return this.state;
  37.     }
  38.     // ... etc
  39. }

注 你可以使用@EntityScan注解自定义实体扫描路径，具体参考Section 74.4, “Separate @Entity definitions from Spring configuration”。