SpringData系列三 Repository Bean 方法定义规范
本节主要介绍Repository Bean中方法定义规范。
1、方法不是随便声明，需要符合一定的规范。
2、按照Spring Data的规范，查询方法以find|read|get开头，涉及条件查询时，条件的属性用条件关键字连接，要注意的是：条件属性需要首字母大写。
3、Spring Data支持的关键字如下：
4、支持属性的级联查询，若当前类有符合条件的属性，则优先使用，而不使用级联属性。若想使用级联属性，则属性之间用"_"连接。
1 package com.ntjr.springdata;
2
3 import java.util.Date;
4
5 import javax.persistence.CascadeType;
6 import javax.persistence.Column;
7 import javax.persistence.Entity;
8 import javax.persistence.GeneratedValue;
9 import javax.persistence.Id;
10 import javax.persistence.JoinColumn;
11 import javax.persistence.ManyToOne;
12 import javax.persistence.Table;
13
14 @Table(name = "JPA_PERSONS")
15 @Entity
16 public class Person {
17
18 private Integer id;
19 private String lastName;
20 private String email;
21 private Date birth;
22 private Address address;
23 private Integer addressId;
24
25 @GeneratedValue
26 @Id
27 public Integer getId() {
28 return id;
29 }
30
31 public void setId(Integer id) {
32 this.id = id;
33 }
34
35 public String getLastName() {
36 return lastName;
37 }
38
39 @Column(name = "LAST_NAME")
40 public void setLastName(String lastName) {
41 this.lastName = lastName;
42 }
43
44 public String getEmail() {
45 return email;
46 }
47
48 public void setEmail(String email) {
49 this.email = email;
50 }
51
52 public Date getBirth() {
53 return birth;
54 }
55
56 public void setBirth(Date birth) {
57 this.birth = birth;
58 }
59
60 @JoinColumn(name = "ADDRESS_ID")
61 @ManyToOne(cascade = { CascadeType.ALL }, targetEntity = Address.class)
62 public Address getAddress() {
63 return address;
64 }
65
66 public void setAddress(Address address) {
67 this.address = address;
68 }
69
70
71 public Integer getAddressId() {
72 return addressId;
73 }
74
75 public void setAddressId(Integer addressId) {
76 this.addressId = addressId;
77 }
78
79 @Override
80 public String toString() {
81 return "Person [id=" + id + ", lastName=" + lastName + ", email=" + email + ", birth=" + birth + "]";
82 }
83
84 }
1 package com.ntjr.springdata;
2
3 import javax.persistence.Entity;
4 import javax.persistence.GeneratedValue;
5 import javax.persistence.Id;
6 import javax.persistence.Table;
7
8 @Table(name="JPA_ADDRESSES")
9 @Entity
10 public class Address {
11
12 private Integer id;
13 private String province;
14 private String city;
15
16 @GeneratedValue
17 @Id
18 public Integer getId() {
19 return id;
20 }
21
22 public void setId(Integer id) {
23 this.id = id;
24 }
25
26 public String getProvince() {
27 return province;
28 }
29
30 public void setProvince(String province) {
31 this.province = province;
32 }
33
34 public String getCity() {
35 return city;
36 }
37
38 public void setCity(String city) {
39 this.city = city;
40 }
41
42 }
1 package com.ntjr.springdata;
2
3 import java.util.Date;
4 import java.util.List;
5
6 import org.springframework.data.repository.RepositoryDefinition;
7
8 /**
9 *
10 * 1、实现Repository接口 2、通过注解的方式@RepositoryDefinition将一个bean定义为Repository接口
11 */
12 @RepositoryDefinition(idClass = Integer.class, domainClass = Person.class)
13 public interface PersonRepsitory {
14 // 根据lastName获取对应的person
15 Person getByLastName(String lastName);
16
17 // WHERE lastName like ?% AND id<?
18 List<Person> findByLastNameStartingWithAndIdLessThan(String lastName, Integer id);
19
20 // WHERE lastName Like %? And Id <?
21 List<Person> findByLastNameEndingWithAndIdLessThan(String lastName, Integer id);
22
23 // WHERE email IN(?,?,?) Or birth <?
24 List<Person> findByEmailInOrBirthLessThan(List<String> emails, Date birth);
25
26 // WHERE a.id >?
27 /**
28 * AddressId 优先查找Person类中的AddressId属性，如果Person类中没有，就查找Address类中的Id属性
29 * 这样容易出现问题，建议级联查询中，属性之间使用"_"连接
30 *
31 */
32 List<Person> findByAddressIdGreaterThan(Integer id);
33
34 // 这样就很明确是进行级联查询，Address类中的ID属性
35 List<Person> findByAddress_IdGreaterThan(Integer id);
36 }
