java - 实体映射中序列的增量大小设置为[50]，而关联的数据库序列增量大小为1

Question

我正在尝试在我的第一个 sprinboot 应用程序中配置 postgreSQL 数据库的属性。但是当我运行这个应用程序时，我收到以下错误:

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'requestMappingHandlerAdapter' defined in class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]: Unsatisfied dependency expressed through method 'requestMappingHandlerAdapter' parameter 1; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'mvcConversionService' defined in class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.format.support.FormattingConversionService]: Factory method 'mvcConversionService' threw exception; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'employeeRepository' defined in com.jrp.pma.dao.EmployeeRepository defined in @EnableJpaRepositories declared on JpaRepositoriesRegistrar.EnableJpaRepositoriesConfiguration: Cannot resolve reference to bean 'jpaMappingContext' while setting bean property 'mappingContext'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'jpaMappingContext': Invocation of init method failed; nested exception is javax.persistence.PersistenceException: [PersistenceUnit: default] Unable to build Hibernate SessionFactory; nested exception is org.hibernate.MappingException: Could not instantiate id generator [entity-name=com.jrp.pma.entities.Project]
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.format.support.FormattingConversionService]: Factory method 'mvcConversionService' threw exception; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'employeeRepository' defined in com.jrp.pma.dao.EmployeeRepository defined in 
    ... 39 common frames omitted

Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'employeeRepository' defined in com.jrp.pma.dao.EmployeeRepository defined in @EnableJpaRepositories declared on JpaRepositoriesRegistrar.EnableJpaRepositoriesConfiguration: Cannot resolve reference to bean 'jpaMappingContext' while setting bean property 'mappingContext'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'jpaMappingContext': Invocation of init method failed; nested exception is javax.persistence.PersistenceException: [PersistenceUnit: default] Unable to build Hibernate SessionFactory; nested exception is org.hibernate.MappingException: Could not instantiate id generator [entity-name=com.jrp.pma.entities.Project]
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'jpaMappingContext': Invocation of init method failed; nested exception is javax.persistence.PersistenceException: [PersistenceUnit: default] Unable to build Hibernate SessionFactory; nested exception is org.hibernate.MappingException: Could not instantiate id generator [entity-name=com.jrp.pma.entities.Project]
    at 
Caused by: javax.persistence.PersistenceException: [PersistenceUnit: default] Unable to build Hibernate SessionFactory; nested exception is org.hibernate.MappingException: Could not instantiate id generator [entity-name=com.jrp.pma.entities.Project]
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:403) ~[spring-orm-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[na:1.8.0_201]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) ~[na:1.8.0_201]
Caused by: org.hibernate.MappingException: The increment size of the [project_seq] sequence is set to [50] in the entity mapping while the associated database sequence increment size is [1].
    at 
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.transaction.annotation.ProxyTransactionManagementConfiguration': Initialization of bean failed; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'org.springframework.context.annotation.ConfigurationClassPostProcessor.importRegistry' available
    at 

PostgreSQL 属性:

spring.datasource.url=jdbc:postgresql://localhost:5432/pma-springbootdb
spring.datasource.username=***
spring.datasource.password=***
spring.datasource.initialization-mode=never
spring.jpa.hibernate.ddl-auto=none
spring.jpa.properties.hibernate.jdbc.lob.non_contextual_creation=true
spring.jpa.show-sql=true
spring.thymeleaf.cache=false

版本=3.0.0

SQL查询:

CREATE SEQUENCE IF NOT EXISTS employee_seq;

CREATE TABLE IF NOT EXISTS employee (
   employee_id BIGINT NOT NULL DEFAULT nextval('employee_seq') PRIMARY KEY,
   email VARCHAR(100) NOT NULL,
   first_name VARCHAR(100) NOT NULL,
   last_name VARCHAR(100) NOT NULL
);

CREATE SEQUENCE IF NOT EXISTS project_seq;

CREATE TABLE IF NOT EXISTS project (
   project_id BIGINT NOT NULL DEFAULT nextval('project_seq') PRIMARY KEY,
   name VARCHAR(100) NOT NULL,
   stage VARCHAR(100) NOT NULL,
   description VARCHAR(500) NOT NULL
);

CREATE TABLE IF NOT EXISTS project_employee (
   project_id BIGINT REFERENCES project, 
   employee_id BIGINT REFERENCES employee
);

项目.java

@Entity
public class Project {

   @Id
   @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "project_seq")
   private Long projectId;
   ....
   ....
}

员工.java:

@Entity
public class Employee {
   @Id
   @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "employee_seq")
   private long employeeId;
   ...
   ..
}

Answer 1

看起来您应该使用 @SequenceGenerator注释与 @GeneratedValue 一起使用显式指定 project_seq 的增量大小的注释序列。

你可以这样做:

@Id
@GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "project_seq")
@SequenceGenerator(name = "project_seq", sequenceName = "project_seq", allocationSize = 1)
private Long projectId;

默认情况下 allocationSize是 50。