Repository接口
public interface Repository<T, ID> {....}
提供了按方法名称的查询方式；
提供了@Query的查询方式
可能遇到的错误：
1）Caused by: javax.persistence.TransactionRequiredException: Executing an update/delete query（手动加@Transactional解决）
2）如果test方法里加事务注解数据不更新的话，还需要手动加@Rollback（false）解决，自己测试的时候，只加了一个@Transactional就更新成功了.
CrudRepository接口
public interface CrudRepository<T, ID> extends Repository<T, ID> {....}
public void test1 () {
JpaUser jpaUser = new JpaUser("名称1","地址1",,,);
Optional<JpaUser> optionalT = userRespotory.findById() ;
Iterable<JpaUser> list = userRespotory.findAll();
userRespotory.delete(jpaUser);
userRespotory.save(jpaUser);//保存or更新
PagingAndSortingRepository接口
public interface PagingAndSortingRepository<T, ID> extends CrudRepository<T, ID> {
Iterable<T> findAll(Sort var1);
Page<T> findAll(Pageable var1);
}
//测试sort
public void test1 () {
JpaUser jpaUser = new JpaUser("名称1","地址1",,,);
Sort sort = new Sort(Sort.Direction.DESC,"id");
Iterable<JpaUser> list = userRespotory.findAll(sort);
//测试page
public void test1 () {
JpaUser jpaUser = new JpaUser("名称1","地址1",10,20,100);
Pageable pageable = PageRequest.of(0, 2);
Page<JpaUser> page = userRespotory.findAll(pageable);
System.out.println(page.getTotalElements());//总条数
System.out.println(page.getTotalPages());//总页数
System.out.println(page.getContent());//当前页集合
//测试分页+排序
public void test1 () {
JpaUser jpaUser = new JpaUser("名称1","地址1",10,20,100);
Pageable pageable = PageRequest.of(1, 2,Sort.Direction.DESC,"id","age1");
Page<JpaUser> page = userRespotory.findAll(pageable);
System.out.println(page.getTotalElements());//总条数
System.out.println(page.getTotalPages());//总页数
System.out.println(page.getContent());//当前页集合
JpaRepository接口
public interface JpaRepository<T, ID> extends PagingAndSortingRepository<T, ID>, QueryByExampleExecutor<T> {....}
JpaSpecificationExecutor接口
public interface JpaSpecificationExecutor<T> {
Optional<T> findOne(@Nullable Specification<T> var1);
List<T> findAll(@Nullable Specification<T> var1);
Page<T> findAll(@Nullable Specification<T> var1, Pageable var2);
List<T> findAll(@Nullable Specification<T> var1, Sort var2);
long count(@Nullable Specification<T> var1);
}
可多条件查询，分页和排序，和以上接口联合使用。
public interface UserSpecificationExcutor extends JpaRepository<JpaUser,Integer> , JpaSpecificationExecutor<JpaUser> {....}
@Autowired
UserSpecificationExcutor userSpecificationExcutor;
@Test
public void test1 () {
Specification<JpaUser> specification = new Specification<JpaUser>() {
@Override
public Predicate toPredicate(Root<JpaUser> root, CriteriaQuery<?> criteriaQuery, CriteriaBuilder criteriaBuilder) {
Predicate predicate = criteriaBuilder.equal(root.get("name"), "名称1");
List<Predicate> list = new ArrayList<>();
list.add(predicate);
predicate = criteriaBuilder.equal(root.get("age1"), );
list.add(predicate); return criteriaBuilder.and(list.toArray(new Predicate[list.size()]));
}
};
List<JpaUser> list = userSpecificationExcutor.findAll(specification);
System.out.println(list);
一对对关联关系role-user
@Test
public void test1 () {
JpaUser jpaUser = new JpaUser("jpaName","diz地址" , , );
jpaUser.setId();
UserRole userRole = new UserRole();
userRole.setName("role名字");
userRole.setName1("role名字");
userRole.setName2("role名字");
userRole.getUserSet().add(jpaUser);
jpaUser.setUserRole(userRole);
userSpecificationExcutor.save(jpaUser);
package com.example.zs.springDataJpa; import javax.persistence.*;
import java.util.HashSet;
import java.util.Set; @Entity
@Table(name="t_role")
public class UserRole {
@Id( )
@GeneratedValue(strategy=GenerationType.IDENTITY)
@Column(name="id")
private Integer id ;
@Column(name="name")
private String name;
@Column(name="name1")
private String name1;
@Column(name="name2")
private String name2;
@OneToMany(mappedBy="userRole")
private Set<JpaUser> userSet = new HashSet<>(); 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;
} public Set<JpaUser> getUserSet() {
return userSet;
} public void setUserSet(Set<JpaUser> userSet) {
this.userSet = userSet;
} public String getName1() {
return name1;
} public void setName1(String name1) {
this.name1 = name1;
} public String getName2() {
return name2;
} public void setName2(String name2) {
this.name2 = name2;
}
}
package com.example.zs.springDataJpa; import javax.persistence.*; @Entity
@Table(name="t_user")
public class JpaUser {
@Column(name="name")
private String name ;
@Column(name="address")
private String address ;
@Column(name="id")
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id ;
@Column(name="age1")
private Integer age ;
@Column(name="age11")
private Integer age1 ;
@ManyToOne(cascade = CascadeType.PERSIST)
@JoinColumn(name="roleFK")
private UserRole userRole; public JpaUser(String name, String address, Integer age, Integer age1 ) {
this.name = name;
this.address = address;
this.age = age;
this.age1 = age1;
// this.id = id;
} public JpaUser() {
} @Override
public String toString() {
return "JpaUser{" +
"name='" + name + '\'' +
", address='" + address + '\'' +
", id=" + id +
", age=" + age +
", age1=" + age1 +
'}';
} public String getName() {
return name;
} public void setName(String name) {
this.name = name;
} public String getAddress() {
return address;
} public void setAddress(String address) {
this.address = address;
} 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 Integer getAge1() {
return age1;
} public void setAge1(Integer age1) {
this.age1 = age1;
} public UserRole getUserRole() {
return userRole;
} public void setUserRole(UserRole userRole) {
this.userRole = userRole;
}
}
public interface UserSpecificationExcutor extends JpaRepository<JpaUser,Integer> , JpaSpecificationExecutor<JpaUser> {
}