的JPA元信息,是应用与数据库表映射的关键
实体类Fruit.java如下,有几处要注意的地方稍后会提到
package com.bolingcavalry.db.entity;
import javax.persistence.Cacheable;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.NamedQuery;
import javax.persistence.QueryHint;
import javax.persistence.SequenceGenerator;
import javax.persistence.Table;
@Entity
@Table(name = "known_fruits")
@NamedQuery(name = "Fruits.findAll", query = "SELECT f FROM Fruit f ORDER BY f.name", hints = @QueryHint(name = "org.hibernate.cacheable", value = "true"))
@Cacheable
public class Fruit {
@Id
@SequenceGenerator(name = "fruitsSequence", sequenceName = "known_fruits_id_seq", allocationSize = 1, initialValue = 10)
@GeneratedValue(generator = "fruitsSequence")
private Integer id;
@Column(length = 40, unique = true)
private String name;
public Fruit() {
}
public Fruit(String name) {
this.name = name;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
- 注解Table确定了表名known_fruits
- 增加了一个自定义SQL,名为Fruits.findAll,后面会用到
- 注解SequenceGenerator定义了known_fruits的自增主键的信息,初始值是10,也就是说通过当前应用新增的第一条记录,ID等于10
- known_fruits表只有两个字段:id和name
service层
- 为known_fruits表的操作增加一个服务类,用于上层的调用(所谓上层是指web接口、gRPC接口、消息消费入口等)
- 服务类名为FruitService.java,为了省事儿就直接用class,不写interface了,代码如下,增删改查服务其实就是EntityManager的基本操作,这就不赘述了:
package com.bolingcavalry.db.service;
import com.bolingcavalry.db.entity.Fruit;
import javax.enterprise.context.ApplicationScoped;
import javax.inject.Inject;
import javax.persistence.EntityManager;
import javax.transaction.Transactional;
import java.util.List;
@ApplicationScoped
public class FruitService {
@Inject
EntityManager entityManager;
public List<Fruit> get() {
return entityManager.createNamedQuery("Fruits.findAll", Fruit.class)
.getResultList();
}
public Fruit getSingle(Integer id) {
return entityManager.find(Fruit.class, id);
}
@Transactional
public void create(Fruit fruit) {
entityManager.persist(fruit);
}
@Transactional
public void update(Integer id, Fruit fruit) {
Fruit entity = entityManager.find(Fruit.class, id);
if (null!=entity) {
entity.setName(fruit.getName());
}
}
@Transactional
public void delete(Integer id) {
Fruit entity = entityManager.getReference(Fruit.class, id);
if (null!=entity) {
entityManager.remove(entity);
}
}
}
- 代码写到这里其实已经完成了,当前工程已经有了数据库增删改查的能力,至于上层如何使用(是web调用、gRPC调用、消费消息),那并非本篇的重点,您可以根据自己需要随意添加
- 为了验证服务类功能正常,接下来会写一个单元测试类 ,调用FruitService的各API并验证数据是否符合预期
单元测试类
- 单元测试类只有一个,位置在quarkus-tutorials/basic-db/src/test/java,这是符合maven规范的测试类位置
- FruitServiceTest源码如下,有几处要注意的地方稍后会提到
package com.bolingcavalry;
import com.bolingcavalry.db.entity.Fruit;
import com.bolingcavalry.db.service.FruitService;
import io.quarkus.test.junit.QuarkusTest;
import org.junit.jupiter.api.*;
import javax.inject.Inject;
import java.util.List;
@QuarkusTest
@TestMethodOrder(MethodOrderer.OrderAnnotation.class)
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