JPA：java.lang.IllegalArgumentException：不是实体
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JPA: java.lang.IllegalArgumentException: Not an entity
提问by David Brossard
I wrote a simple Java that uses POJOs, servlets, JSPs. I am using:
我编写了一个使用 POJO、servlet、JSP 的简单 Java。我在用：
- Tomcat 7.0.16
- Oracle 11g
- Oracle Java build 1.6.0_26-b03
- 雄猫 7.0.16
- 甲骨文 11g
- Oracle Java 版本 1.6.0_26-b03
I use ivy to resolve my dependencies:
我使用 ivy 来解决我的依赖项：
<dependency org="oracle" name="ojdbc6" rev="11g" conf="default -> default" />
<dependency org="org.hibernate" name="hibernate-commons-annotations" rev="3.2.0.Final" conf="compile -> runtime" />
<dependency org="org.hibernate" name="hibernate-annotations" rev="3.5.6-Final" conf="default -> runtime" />
<dependency org="org.hibernate" name="hibernate-core" rev="3.6.5.Final" conf="default -> runtime" />
<dependency org="org.hibernate" name="hibernate-validator" rev="4.0.2.GA" conf="runtime -> runtime" />
<dependency org="org.hibernate.javax.persistence" name="hibernate-jpa-2.0-api" rev="1.0.1.Final" conf="compile -> default" />
<dependency org="org.hibernate" name="hibernate-entitymanager" rev="3.6.5.Final" conf="compile -> default" />
My POJO Vehicle contains the following annotations:
我的 POJO Vehicle 包含以下注释：
import java.io.Serializable;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Version;
@Entity
public class Vehicle implements Serializable{
/**
*
*/
private static final long serialVersionUID = 8560417193012227968L;
@Id
@GeneratedValue(strategy=GenerationType.AUTO)
private Long identifier;
private String serialNumber;
private String model;
private String manufacturer;
private int year;
private String condition;
@Version
private long version;
public Vehicle(){
}
When I run my code, I get the following:
当我运行我的代码时，我得到以下信息：
2013-10-28 11:40:50 ERROR SqlVehicleService:42 - java.lang.IllegalArgumentException: Not an entity: class com.foo.demos.car.model.Vehicle
java.lang.IllegalArgumentException: Not an entity: class com.foo.demos.car.model.Vehicle
at org.hibernate.ejb.metamodel.MetamodelImpl.entity(MetamodelImpl.java:160)
at org.hibernate.ejb.criteria.QueryStructure.from(QueryStructure.java:138)
at org.hibernate.ejb.criteria.CriteriaQueryImpl.from(CriteriaQueryImpl.java:179)
at com.foo.demos.car.impl.SqlVehicleService.getVehicles(SqlVehicleService.java:37)
at org.apache.jsp.secured.vehicles_jsp._jspService(vehicles_jsp.java:194)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:419)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:389)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:333)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:304)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:240)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:164)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:572)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:164)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:563)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:403)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:301)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:162)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:309)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:662)
My persistence.xmldoes not contain any information about Vehicle. My understanding is that annotations are enough. Is that correct?
Mypersistence.xml不包含任何关于 Vehicle 的信息。我的理解是注释就足够了。那是对的吗？
<?xml version="1.0" encoding="UTF-8"?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd"
version="1.0">
<persistence-unit name="cardemo">
<provider>org.hibernate.ejb.HibernatePersistence</provider>
<!-- the JNDI data source -->
<non-jta-data-source>java:comp/env/jdbc/cardemo</non-jta-data-source>
<properties>
<property name="javax.persistence.validation.mode" value="NONE" />
<!-- if this is true, hibernate will print (to stdout) the SQL it executes,
so you can check it to ensure it"s not doing anything crazy -->
<property name="hibernate.show_sql" value="true" />
<property name="hibernate.format_sql" value="true" />
<!-- since most database servers have slightly different versions of the
SQL, Hibernate needs you to choose a dialect so it knows the subtleties of
talking to that server -->
<property name="hibernate.dialect" value="org.hibernate.dialect.Oracle10gDialect" />
<!-- this tell Hibernate to update the DDL when it starts, very useful
for development, dangerous in production -->
<property name="hibernate.hbm2ddl.auto" value="update" />
</properties>
</persistence-unit>
</persistence>
I obviously overlooked something. What's that? What am I missing?
我显然忽略了一些东西。那是什么？我错过了什么？
采纳答案by JB Nizet
My persistence.xml does not contain any information about Vehicle. My understanding is that annotations are enough. Is that correct?
我的persistence.xml 不包含任何关于Vehicle 的信息。我的理解是注释就足够了。那是对的吗？
No, it's not. The entities must be listed in the persistence.xml file, under the persistence-unit element:
不，这不对。实体必须列在 persistence.xml 文件中的 persistence-unit 元素下：
<class>com.foo.demos.car.model.Vehicle</class>
回答by Alan Hay
You need to give a hint to where the persistent entities can be found. I normally configure via Spring so don't have the exact info required however look here for some further discussion.
您需要提示可以找到持久实体的位置。我通常通过 Spring 进行配置，因此没有所需的确切信息，但请在此处查看进一步讨论。
回答by user8340242
you can specify your entity locations via <property name="packagesToScan" value="" />in the persistence.xml
您可以通过<property name="packagesToScan" value="" />在 persistence.xml 中指定您的实体位置
回答by Zon
If you dynamicallybuild your persistence and add properties, you can declare entity classesusing 'org.reflections:reflections:0.9.11':
如果您动态构建持久性并添加属性，则可以使用以下方法声明实体类'org.reflections:reflections:0.9.11'：
new HibernatePersistenceProvider()
.createContainerEntityManagerFactory(
new javax.persistence.spi.PersistenceUnitInfoImpl(persistenceUnitName),
ImmutableMap.<String, Object>builder()
.put(AvailableSettings.LOADED_CLASSES, getEntities())
.build());
...
private List<Class<?>> getEntities() {
Set<Class<?>> entitiesInPackage = new Reflections("rf.dom.model")
.getTypesAnnotatedWith(Entity.class); // Annotated @Entity
List entities = new ArrayList<>(entitiesInPackage);
return entities;
}
回答by parsecer
My problem was that I created a SessionFactorylike this:
我的问题是我创建了一个SessionFactory这样的：
Configuration configuration = new Configuration();
configuration.configure();
serviceRegistry = new StandardServiceRegistryBuilder().applySettings(configuration.getProperties()).build();
sessionFactory = configuration.buildSessionFactory(serviceRegistry);
instead of like this:
而不是这样：
Configuration configuration = new Configuration();
configuration.configure();
sessionFactory = configuration.buildSessionFactory();
When I replaced the former with the later, it worked! So be careful when using SessionFactory's initialization from tutorials.
当我用后者替换前者时，它起作用了！所以在使用SessionFactory教程中的初始化时要小心。
