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JPA自关联 OneToMany小issue 《已解决》

程序员文章站 2022-04-22 21:55:44
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PS: 答案

感谢 jinnianshilongnian同学，终于找到问题所以。

 

发现其实不是自关联的问题，所有的关系都是一样的存在这样的问题，只要注意一下就可避免。
问题出在：
Java persistence 允许两种注解方式去与数据库的table作映射： field和property .
经过测试，这两种方式是不能混着用的， 如果你选择在field上注解就不要再在getter方法上注解。
像我下面成功的代码里，注解都是在field上的，而出问题的代码是因为我的id是注解在field上而其它两个是注解在getter方法上。


总结 ： 各字段的映射要么全在field上要么全在getter方法上，不能混用。

------------------------------------------------------------------------------------------------------------------------------

问题： 

 

        @Id
	@GeneratedValue
	private Integer id;
	private String name;
	@ManyToOne
	private Part bomPart;
	@OneToMany(mappedBy = "bomPart")
	private Collection<Part> parts;

 上面的代码没有问题

 而如果把注解加在getter方法上就会报错

 

       @Id
       @GeneratedValue
        private Integer id;
@OneToMany(mappedBy = "bomPart")
	public Collection<Part> getParts() {
		return parts;
	}

	public void setParts(Set<Part> parts) {
		this.parts = parts;
	}

	public Part getBomPart() {
		return bomPart;
	}
	@ManyToOne
	public void setBomPart(Part bomPart) {
		this.bomPart = bomPart;
	}
 

 

 

11:49:52,366 INFO  [org.jboss.as.osgi] (MSC service thread 1-5) JBAS011908: Unregister module: Module "deployment.EJBDBTest.jar:main" from Service Module Loader
11:49:52,379 INFO  [org.jboss.as.server.deployment] (MSC service thread 1-7) JBAS015877: Stopped deployment EJBDBTest.jar in 15ms
11:49:52,381 INFO  [org.jboss.as.server.deployment] (MSC service thread 1-1) JBAS015876: Starting deployment of "EJBDBTest.jar"
11:49:52,401 INFO  [org.jboss.as.jpa] (MSC service thread 1-2) JBAS011401: Read persistence.xml for test
11:49:52,408 INFO  [org.jboss.as.ejb3.deployment.processors.EjbJndiBindingsDeploymentUnitProcessor] (MSC service thread 1-2) JNDI bindings for session bean named DB in deployment unit deployment "EJBDBTest.jar" are as follows:

	java:global/EJBDBTest/DB!com.james.dao.DBRemote
	java:app/EJBDBTest/DB!com.james.dao.DBRemote
	java:module/DB!com.james.dao.DBRemote
	java:jboss/exported/EJBDBTest/DB!com.james.dao.DBRemote
	java:global/EJBDBTest/DB
	java:app/EJBDBTest/DB
	java:module/DB

11:49:52,423 INFO  [org.jboss.as.jpa] (MSC service thread 1-2) JBAS011402: Starting Persistence Unit Service 'EJBDBTest.jar#test'
11:49:52,425 INFO  [org.hibernate.ejb.Ejb3Configuration] (MSC service thread 1-2) HHH000204: Processing PersistenceUnitInfo [
	name: test
	...]
11:49:52,442 ERROR [org.jboss.msc.service.fail] (MSC service thread 1-2) MSC000001: Failed to start service jboss.persistenceunit."EJBDBTest.jar#test": org.jboss.msc.service.StartException in service jboss.persistenceunit."EJBDBTest.jar#test": Failed to start service
	at org.jboss.msc.service.ServiceControllerImpl$StartTask.run(ServiceControllerImpl.java:1767) [jboss-msc-1.0.2.GA-redhat-1.jar:1.0.2.GA-redhat-1]
	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source) [rt.jar:1.6.0_33]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) [rt.jar:1.6.0_33]
	at java.lang.Thread.run(Unknown Source) [rt.jar:1.6.0_33]
Caused by: javax.persistence.PersistenceException: [PersistenceUnit: test] Unable to build EntityManagerFactory
	at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:915)
	at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:890)
	at org.hibernate.ejb.HibernatePersistence.createContainerEntityManagerFactory(HibernatePersistence.java:74)
	at org.jboss.as.jpa.service.PersistenceUnitServiceImpl.createContainerEntityManagerFactory(PersistenceUnitServiceImpl.java:162)
	at org.jboss.as.jpa.service.PersistenceUnitServiceImpl.start(PersistenceUnitServiceImpl.java:85)
	at org.jboss.msc.service.ServiceControllerImpl$StartTask.startService(ServiceControllerImpl.java:1811) [jboss-msc-1.0.2.GA-redhat-1.jar:1.0.2.GA-redhat-1]
	at org.jboss.msc.service.ServiceControllerImpl$StartTask.run(ServiceControllerImpl.java:1746) [jboss-msc-1.0.2.GA-redhat-1.jar:1.0.2.GA-redhat-1]
	... 3 more
Caused by: org.hibernate.MappingException: Could not determine type for: java.util.Collection, at table: part, for columns: [org.hibernate.mapping.Column(parts)]
	at org.hibernate.mapping.SimpleValue.getType(SimpleValue.java:305)
	at org.hibernate.mapping.SimpleValue.isValid(SimpleValue.java:289)
	at org.hibernate.mapping.Property.isValid(Property.java:238)
	at org.hibernate.mapping.PersistentClass.validate(PersistentClass.java:468)
	at org.hibernate.mapping.RootClass.validate(RootClass.java:270)
	at org.hibernate.cfg.Configuration.validate(Configuration.java:1294)
	at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1736)
	at org.hibernate.ejb.EntityManagerFactoryImpl.<init>(EntityManagerFactoryImpl.java:94)
	at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:905)
	... 9 more

11:49:52,448 INFO  [org.jboss.as.osgi] (MSC service thread 1-2) JBAS011907: Register module: Module "deployment.EJBDBTest.jar:main" from Service Module Loader
11:49:52,554 INFO  [org.jboss.as.osgi] (MSC service thread 1-4) JBAS011908: Unregister module: Module "deployment.EJBDBTest.jar:main" from Service Module Loader
11:49:52,574 INFO  [org.jboss.as.server.deployment] (MSC service thread 1-8) JBAS015877: Stopped deployment EJBDBTest.jar in 20ms
11:49:52,579 INFO  [org.jboss.as.server] (DeploymentScanner-threads - 1) JBAS015863: Replacement of deployment "EJBDBTest.jar" by deployment "EJBDBTest.jar" was rolled back with failure message {"JBAS014671: Failed services" => {"jboss.persistenceunit.\"EJBDBTest.jar#test\"" => "org.jboss.msc.service.StartException in service jboss.persistenceunit.\"EJBDBTest.jar#test\": Failed to start service
    Caused by: javax.persistence.PersistenceException: [PersistenceUnit: test] Unable to build EntityManagerFactory
    Caused by: org.hibernate.MappingException: Could not determine type for: java.util.Collection, at table: part, for columns: [org.hibernate.mapping.Column(parts)]"},"JBAS014771: Services with missing/unavailable dependencies" => ["jboss.deployment.unit.\"EJBDBTest.jar\".component.DB.START Missing[JBAS014861: <one or more transitive dependencies>]","jboss.naming.context.java.comp.EJBDBTest.EJBDBTest.DB.env.\"com.james.dao.DB\".em Missing[JBAS014861: <one or more transitive dependencies>]","jboss.deployment.unit.\"EJBDBTest.jar\".jndiDependencyService Missing[JBAS014861: <one or more transitive dependencies>]"]}
11:49:52,598 INFO  [org.jboss.as.server.deployment] (MSC service thread 1-5) JBAS015876: Starting deployment of "EJBDBTest.jar"
11:49:52,623 INFO  [org.jboss.as.jpa] (MSC service thread 1-6) JBAS011401: Read persistence.xml for test
11:49:52,633 INFO  [org.jboss.as.ejb3.deployment.processors.EjbJndiBindingsDeploymentUnitProcessor] (MSC service thread 1-5) JNDI bindings for session bean named DB in deployment unit deployment "EJBDBTest.jar" are as follows:

	java:global/EJBDBTest/DB!com.james.dao.DBRemote
	java:app/EJBDBTest/DB!com.james.dao.DBRemote
	java:module/DB!com.james.dao.DBRemote
	java:jboss/exported/EJBDBTest/DB!com.james.dao.DBRemote
	java:global/EJBDBTest/DB
	java:app/EJBDBTest/DB
	java:module/DB

11:49:52,650 INFO  [org.jboss.as.osgi] (MSC service thread 1-1) JBAS011907: Register module: Module "deployment.EJBDBTest.jar:main" from Service Module Loader
11:49:52,650 INFO  [org.jboss.as.jpa] (MSC service thread 1-8) JBAS011402: Starting Persistence Unit Service 'EJBDBTest.jar#test'
11:49:52,651 INFO  [org.hibernate.ejb.Ejb3Configuration] (MSC service thread 1-8) HHH000204: Processing PersistenceUnitInfo [
	name: test
	...]
11:49:52,663 ERROR [org.jboss.msc.service.fail] (MSC service thread 1-8) MSC000001: Failed to start service jboss.persistenceunit."EJBDBTest.jar#test": org.jboss.msc.service.StartException in service jboss.persistenceunit."EJBDBTest.jar#test": Failed to start service
	at org.jboss.msc.service.ServiceControllerImpl$StartTask.run(ServiceControllerImpl.java:1767) [jboss-msc-1.0.2.GA-redhat-1.jar:1.0.2.GA-redhat-1]
	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source) [rt.jar:1.6.0_33]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) [rt.jar:1.6.0_33]
	at java.lang.Thread.run(Unknown Source) [rt.jar:1.6.0_33]
Caused by: javax.persistence.PersistenceException: [PersistenceUnit: test] Unable to build EntityManagerFactory
	at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:915)
	at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:890)
	at org.hibernate.ejb.HibernatePersistence.createContainerEntityManagerFactory(HibernatePersistence.java:74)
	at org.jboss.as.jpa.service.PersistenceUnitServiceImpl.createContainerEntityManagerFactory(PersistenceUnitServiceImpl.java:162)
	at org.jboss.as.jpa.service.PersistenceUnitServiceImpl.start(PersistenceUnitServiceImpl.java:85)
	at org.jboss.msc.service.ServiceControllerImpl$StartTask.startService(ServiceControllerImpl.java:1811) [jboss-msc-1.0.2.GA-redhat-1.jar:1.0.2.GA-redhat-1]
	at org.jboss.msc.service.ServiceControllerImpl$StartTask.run(ServiceControllerImpl.java:1746) [jboss-msc-1.0.2.GA-redhat-1.jar:1.0.2.GA-redhat-1]
	... 3 more
Caused by: org.hibernate.MappingException: Could not determine type for: java.util.Collection, at table: part, for columns: [org.hibernate.mapping.Column(parts)]
	at org.hibernate.mapping.SimpleValue.getType(SimpleValue.java:305)
	at org.hibernate.mapping.SimpleValue.isValid(SimpleValue.java:289)
	at org.hibernate.mapping.Property.isValid(Property.java:238)
	at org.hibernate.mapping.PersistentClass.validate(PersistentClass.java:468)
	at org.hibernate.mapping.RootClass.validate(RootClass.java:270)
	at org.hibernate.cfg.Configuration.validate(Configuration.java:1294)
	at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1736)
	at org.hibernate.ejb.EntityManagerFactoryImpl.<init>(EntityManagerFactoryImpl.java:94)
	at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:905)
	... 9 more

11:49:52,666 INFO  [org.jboss.as.controller] (DeploymentScanner-threads - 1) JBAS014774: Service status report
JBAS014777:   Services which failed to start:      service jboss.persistenceunit."EJBDBTest.jar#test": org.jboss.msc.service.StartException in service jboss.persistenceunit."EJBDBTest.jar#test": Failed to start service
 

求解释！

 

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