标签：return connector builder list 持久化 art exe number content
StringData JPA 是微服务框架下一款ORM框架，在微服务体系架构下，数据持久化框架，主要为SpringData JPA及Mybatis两种，这两者的具体比较，本文不做阐述，本文只简单阐述SpringData JPA的使用方法。
SpringData JPA的Repository接口介绍，本文主要介绍CrudRepository、PagingAndSortingRepository、JpaSpecificationExecutor。
pom.xml
<!--Springboot-web-->
<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency>
<!--SpringData-JPA--> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-jpa</artifactId> </dependency> <!--mysql启动--> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <scope>runtime</scope> </dependency>
<!--测试驱动--> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency>
entity：
/*
* 数据实体，表名test_emp
*/
@Entity @Table(name="test_emp") public class Emp implements Serializable{ private static final long serialVersionUID = 1L; @Id @GeneratedValue(strategy=GenerationType.AUTO) private Integer id; @Column private Integer age; @Column private String name; public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public Integer getAge() { return age; } public void setAge(Integer age) { this.age = age; } public String getName() { return name; } public void setName(String name) { this.name = name; } @Override public String toString() { return "Emp [id=" + id + ", age=" + age + ", name=" + name + "]"; } }
CrudRepository实现：
public interface EmpCrudRepository extends CrudRepository<Emp, Integer> {
/*
*Query高级查询
*/
@Query("select e from Emp e")
public List<Emp> queryAllTest();
}
PagingAndSortingRepository实现：
public interface EmpPagingAndSortingRepository extends PagingAndSortingRepository<Emp, Integer> {
}
EmpJpaSpecificationExecutor实现：
public interface EmpJpaSpecificationExecutor extends JpaSpecificationExecutor<Emp>,Repository<Emp, Integer>{
}
CurdRepository测试：
@SpringBootTest
@RunWith(SpringRunner.class)
public class EmpCurdRepositoryTest {
@Autowired
private EmpCrudRepository empCrudRepository;
@Test
public void testAdd() {
Emp emp = new Emp();
emp.setAge(22);
emp.setId(1);
emp.setName("test1");
empCrudRepository.save(emp);
}
@Test
public void testAddAll() {
List<Emp> emps = new ArrayList<>();
for (int i = 0; i < 10; i++) {
Emp emp = new Emp();
emp.setAge(i+20);
emp.setName("test"+i);
emps.add(emp);
}
empCrudRepository.saveAll(emps);
}
/**
* Query注解使用
*/
@Test
public void testQueryAll() {
List<Emp> emps = empCrudRepository.queryAllTest();
for(Emp emp:emps) {
System.out.println(emp);
}
}
}
PagingAndSortingRepository测试：
@SpringBootTest
@RunWith(SpringRunner.class)
public class EmpPagingAndSortingRepositoryTest {
@Autowired
private EmpPagingAndSortingRepository empPagingAndSortingRepository;
@Test
public void query() {
Pageable pageable = PageRequest.of(0, 10, Direction.DESC, "id");
Iterable<Emp> emps = empPagingAndSortingRepository.findAll(pageable);
for(Emp emp:emps) {
System.out.println(emp);
}
}
@Test
public void queryAll() {
Pageable pageable = PageRequest.of(0, 7, Direction.DESC, "id");
Page<Emp> result = empPagingAndSortingRepository.findAll(pageable); //查询结果是pageable对象
// Iterable<Emp> emps = empPagingAndSortingRepository.findAll(pageable); //查询结果直接是emp对象
System.out.println(result.getContent());
System.out.println(result.getNumber());
System.out.println(result.getNumberOfElements());
System.out.println(result.getTotalElements());
System.out.println(result.getTotalPages());
for(Emp emp:result.getContent()) {
System.out.println(emp);
}
}
}
JpaSpecificationExecutor测试：
@RunWith(SpringRunner.class)
@SpringBootTest
public class EmpJpaSpecificationExecutorTest {
@Autowired
private EmpJpaSpecificationExecutor empJpaSpecificationExecutor;
@Test
public void test() {
Specification<Emp> spec = new Specification<Emp>() {
@Override
//多种复杂条件组合查询，属于JPA高级
public Predicate toPredicate(Root<Emp> root, CriteriaQuery<?> query, CriteriaBuilder cb) {
List<Predicate> predicates = new ArrayList<>();
Predicate p1 = cb.gt(root.get("age"), 25);
Predicate p2 = cb.lt(root.get("age"), 28);
Predicate p3 = cb.and(p1,p2);
predicates.add(p3);
return query.where(predicates.toArray(new Predicate[predicates.size()])).getRestriction();
}
};
Pageable pageable = PageRequest.of(0, 5, Direction.ASC, "id");
Page<Emp> emps = empJpaSpecificationExecutor.findAll(spec, pageable);
for (Emp emp: emps.getContent()) {
System.out.println(emp);
}
}
}
标签：return connector builder list 持久化 art exe number content
原文地址：https://www.cnblogs.com/pengteng/p/10180516.html
