Spring Data JPA使用复合主键

演示环境

MySQL 5.7

JDK1.8

spring-data-jpa 1.10.4.RELEASE

hibernate 5.1.2.Final

这里演示一个余额宝的例子，一个用户一天一条记录，表示一个用户一天的收益情况。其中，用户ID，日期是复合主键

项目总体结构如下：

下面依次贴出源代码

pom.xml

1. <project xmlns=“http://maven.apache.org/POM/4.0.0” xmlns:xsi=“http://www.w3.org/2001/XMLSchema-instance”
2. xsi:schemaLocation=“http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd”>
3. <modelVersion>4.0.0</modelVersion>
5. <groupId>com.pp.jpa</groupId>
6. <artifactId>springdata-jpa</artifactId>
7. <version>1.0.0</version>
8. <packaging>jar</packaging>
10. <name>springdata-jpa</name>
11. <url>http://maven.apache.org</url>
13. <properties>
14. <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
15. <maven.compiler.source>1.8</maven.compiler.source>
16. <maven.compiler.target>1.8</maven.compiler.target>
17. </properties>
19. <dependencies>
20. <dependency>
21. <groupId>mysql</groupId>
22. <artifactId>mysql-connector-java</artifactId>
23. <version>5.1.40</version>
24. </dependency>
25. <dependency>
26. <groupId>org.springframework.data</groupId>
27. <artifactId>spring-data-jpa</artifactId>
28. <version>1.10.4.RELEASE</version>
29. </dependency>
30. <dependency>
31. <groupId>org.hibernate</groupId>
32. <artifactId>hibernate-core</artifactId>
33. <version>5.1.2.Final</version>
34. </dependency>
35. <dependency>
36. <groupId>org.hibernate</groupId>
37. <artifactId>hibernate-entitymanager</artifactId>
38. <version>5.1.2.Final</version>
39. </dependency>
40. <dependency>
41. <groupId>junit</groupId>
42. <artifactId>junit</artifactId>
43. <version>4.12</version>
44. <scope>test</scope>
45. </dependency>
46. </dependencies>
48. </project>

下面依次是Java源码

1. package com.pp.jpa.config;
3. import javax.persistence.EntityManagerFactory;
4. import javax.sql.DataSource;
6. import org.springframework.context.annotation.Bean;
7. import org.springframework.context.annotation.Configuration;
8. import org.springframework.orm.jpa.JpaTransactionManager;
9. import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
10. import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;
11. import org.springframework.transaction.PlatformTransactionManager;
13. import com.mysql.jdbc.jdbc2.optional.MysqlDataSource;
15. @Configuration
16. public class JPAConfiguration {
18. @Bean
19. public DataSource createDataSource(){
20. MysqlDataSource ds = new MysqlDataSource();
21. ds.setURL(“jdbc:mysql://127.0.0.1:3306/jpa”);
22. ds.setUser(“root”);
23. ds.setPassword(“admin123”);
24. return ds;
25. }
27. @Bean(name=“entityManagerFactory”)
28. public EntityManagerFactory createEntityManagerFactory(DataSource dataSource){
29. LocalContainerEntityManagerFactoryBean entityManagerFactory = new LocalContainerEntityManagerFactoryBean();
30. entityManagerFactory.setDataSource(dataSource);
32. HibernateJpaVendorAdapter jpaVendorAdapter = new HibernateJpaVendorAdapter();
33. jpaVendorAdapter.setGenerateDdl(true);
34. jpaVendorAdapter.setShowSql(true);
35. entityManagerFactory.setPackagesToScan(“com.pp.jpa.entity”);
36. entityManagerFactory.setJpaVendorAdapter(jpaVendorAdapter);
37. entityManagerFactory.afterPropertiesSet();
38. return entityManagerFactory.getObject();
39. }
41. @Bean(name=“transactionManager”)
42. public PlatformTransactionManager createPlatformTransactionManager(EntityManagerFactory entityManagerFactory){
43. JpaTransactionManager transactionManager = new JpaTransactionManager();
44. transactionManager.setEntityManagerFactory(entityManagerFactory);
45. return transactionManager;
46. }
47. }

1. package com.pp.jpa.entity;
3. import java.io.Serializable;
5. import javax.persistence.Embeddable;
7. /**
8. * 主键
9. * 代表复合主键的实体bean需要实现Serializable接口
10. */
11. @Embeddable
12. public class UserFundPrimarykey implements Serializable {
14. private static final long serialVersionUID = 1L;
16. //用户ID
17. private Integer userId;
19. /**
20. * 日期，格式yyyy-MM-dd
21. */
22. private String date;
24. public UserFundPrimarykey() {}
26. public UserFundPrimarykey(Integer userId, String date) {
27. this.userId = userId;
28. this.date = date;
29. }
31. public Integer getUserId() {
32. return userId;
33. }
35. public void setUserId(Integer userId) {
36. this.userId = userId;
37. }
39. public String getDate() {
40. return date;
41. }
43. public void setDate(String date) {
44. this.date = date;
45. }
47. @Override
48. public String toString() {
49. return “UserFundPrimarykey [userId=” + userId + “, date=” + date + “]”;
50. }
51. }

1. package com.pp.jpa.entity;
3. import java.math.BigDecimal;
5. import javax.persistence.Column;
6. import javax.persistence.EmbeddedId;
7. import javax.persistence.Entity;
8. import javax.persistence.Table;
10. /**
11. * 模拟一个余额宝的功能
12. * 一条记录代表一个用户一天的收益信息（本金，利率，利息）
13. */
14. @Entity
15. @Table(name = “user_funds”)
16. public class UserFund {
18. /**
19. * 主键
20. * 复合主键不能用@Id，需要用@EmbeddedId。插入数据的时候必须手工赋值
21. */
22. @EmbeddedId
23. private UserFundPrimarykey userFundPK;
25. //本金
26. @Column(precision=18, scale=5)
27. private BigDecimal principal;
29. //利率（5%传0.05）
30. @Column(precision=18, scale=5)
31. private BigDecimal rate;
33. /**
34. * 当天收益（日利息=本金*利率/365）
35. * 保留2位小数
36. */
37. @Column(precision=18, scale=2)
38. private BigDecimal interest;
40. public UserFundPrimarykey getUserFundPK() {
41. return userFundPK;
42. }
44. public void setUserFundPK(UserFundPrimarykey userFundPK) {
45. this.userFundPK = userFundPK;
46. }
48. public BigDecimal getPrincipal() {
49. return principal;
50. }
52. public void setPrincipal(BigDecimal principal) {
53. this.principal = principal;
54. }
56. public BigDecimal getRate() {
57. return rate;
58. }
60. public void setRate(BigDecimal rate) {
61. this.rate = rate;
62. }
64. public BigDecimal getInterest() {
65. return interest;
66. }
68. public void setInterest(BigDecimal interest) {
69. this.interest = interest;
70. }
72. @Override
73. public String toString() {
74. return “UserFund [userFundPK=” + userFundPK + “, principal=” + principal + “, rate=” + rate + “, interest=”
75. + interest + “]”;
76. }
77. }

1. package com.pp.repository;
3. import org.springframework.data.repository.CrudRepository;
5. import com.pp.jpa.entity.UserFund;
6. import com.pp.jpa.entity.UserFundPrimarykey;
8. public interface UserFundRepository extends CrudRepository<UserFund, UserFundPrimarykey> {
10. }

启动类

1. package com.pp.jpa;
3. import java.math.BigDecimal;
4. import java.math.RoundingMode;
6. import org.springframework.context.annotation.AnnotationConfigApplicationContext;
7. import org.springframework.context.annotation.ComponentScan;
8. import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
9. import org.springframework.transaction.annotation.EnableTransactionManagement;
11. import com.pp.jpa.entity.UserFund;
12. import com.pp.jpa.entity.UserFundPrimarykey;
13. import com.pp.repository.UserFundRepository;
15. @ComponentScan
16. @EnableJpaRepositories(value=“com.pp”)
17. @EnableTransactionManagement
18. public class App {
19. public static void main(String[] args) throws Exception {
20. AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(App.class);
22. UserFund uf1 = new UserFund();
23. //必须手动设置主键
24. uf1.setUserFundPK(new UserFundPrimarykey(1, “2017-07-01”));
25. uf1.setRate(new BigDecimal(“0.041”));
26. uf1.setPrincipal(new BigDecimal(“10000”));
27. //截断，只保留两位小数
28. uf1.setInterest(uf1.getRate().multiply(uf1.getPrincipal()).divide(new BigDecimal(“365”), 2, RoundingMode.DOWN));
30. UserFund uf2 = new UserFund();
31. //必须手动设置主键
32. uf2.setUserFundPK(new UserFundPrimarykey(2, “2017-07-01”));
33. uf2.setRate(new BigDecimal(“0.041”));
34. uf2.setPrincipal(new BigDecimal(“20000”));
35. //截断，只保留两位小数
36. uf2.setInterest(uf2.getRate().multiply(uf2.getPrincipal()).divide(new BigDecimal(“365”), 2, RoundingMode.DOWN));
38. UserFundRepository ur = context.getBean(UserFundRepository.class);
39. ur.save(uf1);
40. ur.save(uf2);
42. ur.findAll().forEach(System.out::println);
44. //查询用户ID=2，在2017-07-01这一天的收益
45. System.out.println(ur.findOne(new UserFundPrimarykey(2, “2017-07-01”)));
46. context.close();
47. }
48. }

一些注意事项和做法已经在备注中有写，大家模仿着写就OK了

直接运行main方法，控制台输出如下信息

1. Hibernate: select userfund0_.date as date1_0_0_, userfund0_.userId as userId2_0_0_, userfund0_.interest as interest3_0_0_, userfund0_.principal as principa4_0_0_, userfund0_.rate as rate5_0_0_ from user_funds userfund0_ where userfund0_.date=? and userfund0_.userId=?
2. Hibernate: insert into user_funds (interest, principal, rate, date, userId) values (?, ?, ?, ?, ?)
3. Hibernate: select userfund0_.date as date1_0_0_, userfund0_.userId as userId2_0_0_, userfund0_.interest as interest3_0_0_, userfund0_.principal as principa4_0_0_, userfund0_.rate as rate5_0_0_ from user_funds userfund0_ where userfund0_.date=? and userfund0_.userId=?
4. Hibernate: insert into user_funds (interest, principal, rate, date, userId) values (?, ?, ?, ?, ?)
5. Hibernate: select userfund0_.date as date1_0_, userfund0_.userId as userId2_0_, userfund0_.interest as interest3_0_, userfund0_.principal as principa4_0_, userfund0_.rate as rate5_0_ from user_funds userfund0_
6. UserFund [userFundPK=UserFundPrimarykey [userId=1, date=2017-07-01], principal=10000.00000, rate=0.04100, interest=1.12]
7. UserFund [userFundPK=UserFundPrimarykey [userId=2, date=2017-07-01], principal=20000.00000, rate=0.04100, interest=2.24]
8. Hibernate: select userfund0_.date as date1_0_0_, userfund0_.userId as userId2_0_0_, userfund0_.interest as interest3_0_0_, userfund0_.principal as principa4_0_0_, userfund0_.rate as rate5_0_0_ from user_funds userfund0_ where userfund0_.date=? and userfund0_.userId=?
9. UserFund [userFundPK=UserFundPrimarykey [userId=2, date=2017-07-01], principal=20000.00000, rate=0.04100, interest=2.24]

查询数据库

select ** from user_funds;