如何使用jpa / hibernate在playframework子模块中保存模型实体

问题描述

每个子模块都有这样的文件夹结构：

• 应用：
  
  
  
  • 控制器
  
  
  • 模型 b $ b
  • views
  
  
  
  
  • submodulename.routes / li>
    
  
  
  • build.sbt
  
  
  
  
  

  喜欢在文件夹中坚持所有的java类实体： models 。

  
  
  

  我应该如何配置play framework和/或hibernate entity manager来扫描这个文件夹
  
  

  我有一个示例模型类，如下所示：
  
  

   包models.common; 
   
   import javax.persistence.CascadeType; 
   import javax.persistence.Column; 
   import javax.persistence.Entity; 
   import javax.persistence.GeneratedValue; 
   import javax.persistence.GenerationType; 
   import javax.persistence.Id; 
   import javax.persistence.ManyToOne; 
   import javax.persistence.NoResultException; 
   
   import controllers.common.Index; 
   import play.data.validation.Constraints; 
  导入play.db.jpa.JPA; 
   $ b $ @Entity 
   public class AppMode {
   public static AppMode getCurrentConfigurationEntry（）{
   return JPA.em（）。find（AppMode.class，1L）; 
  } 
   //其余代码在这里 - 不重要// 
  } 
    

  但在这种状态下，jvm返回一个运行时错误：
  
  pre $ [IllegalArgumentException：Unknown entity：models.common.AppMode ]


  注：我正在使用play 2.2.1

  
  
  

  我注意到，当我在persistance.xml中设置时，hibernate正确地为AppMode实体
  创建了sql结构：

   < property name =hibernate.hbm2ddl.autovalue =create-drop/> 
    

  但是当我走得更远时，我得到了下一个错误：
  
  

    [IllegalArgumentException：org.hibernate.hql.ast.QuerySyntaxException：MIncident未映射
    

  虽然我在该类上注解了@Entity。

  
  
  

  这似乎是正确的映射，但我不能做任何像 hsql select 或 JPA.em（）。find（）这样的实体操作

  解决方案

  我自己解决了这个问题。

  
  
  

  运行时错误： p>
  
  

  [IllegalArgumentException：未知实体：models.common.AppMode]
  由Jpa / Hibernate配置引起。问题是Jpa / Hibernate在编译时看到我的实体（标注@Entity），但是在运行时dosn't。要解决这个问题，我必须手动将所有模型类（实体）指向persistance.xml文件中，如下所示：

  
  
  

  /conf/META-INF/persistence.xml

   < 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_2_0.xsd
   version =2.0> 
   
  < persistence-unit name =defaultPersistenceUnittransaction-type =RESOURCE_LOCAL> 
  < provider> org.hibernate.ejb.HibernatePersistence< / provider> 
  <非-jta-data-source> DefaultDS< /非-jta-data-source> 
  < class> models.common.AppMode< / class> 
  < class> models.Customer< / class> 
  < class> models.Complaint< / class> 
  <属性> 
  < property name =hibernate.hbm2ddl.autovalue =update/> 
  < property name =hibernate.dialectvalue =org.hibernate.dialect.H2Dialect/> 
  < property name =hibernate.show_sqlvalue =true/> 
  < / properties> 
  < / persistence-unit> 
  < /余辉> 
    

  原文：
  

  
  
  

  我想知道为什么在主项目（fe： /app/models/User.java ）我可以使用注释 @javax。 persistence.Entity （它有效），但是在子项目中（fe： /modules/common/app/models/AppMode.java ）它dosnt工作时，注释 @ javax.persistence.Entity 不够，我必须将每个模型类指向persistance.xml文件。

  
  
  

  我认为这是一个playframework中的错误（我检查过2.2.1,2.2.4和2.3.4版本）
  

  I have project in PLAY FRAMEWORK wich contain few submodules.

  Each submodule has folder structure like this:

  • app:
    • controllers
    • models
    • views
  • conf:
    • submodulename.routes
  • build.sbt

  I would like to persist all java class entities in folder: models.

  How should I configure play framework and/or hibernate entity manager to scan this folders for entities.

  I have example model class as follow:

  package models.common;
  
  import javax.persistence.CascadeType;
  import javax.persistence.Column;
  import javax.persistence.Entity;
  import javax.persistence.GeneratedValue;
  import javax.persistence.GenerationType;
  import javax.persistence.Id;
  import javax.persistence.ManyToOne;
  import javax.persistence.NoResultException;
  
  import controllers.common.Index;
  import play.data.validation.Constraints;
  import play.db.jpa.JPA;
  
  @Entity
  public class AppMode {
      public static AppMode getCurrentConfigurationEntry() {
          return JPA.em().find(AppMode.class, 1L);
      }
  //rest of code here- not important//
  }
  

  but in this state jvm return me a runtime error:

  [IllegalArgumentException: Unknown entity: models.common.AppMode]
  

  NOTE : I'm using play 2.2.1

  I've noticed that hibernate is correctly create sql structure for AppMode entitywhen I set this in persistance.xml:

      <property name="hibernate.hbm2ddl.auto" value="create-drop"/>
  

  But when I go further I am getting next error:

  [IllegalArgumentException: org.hibernate.hql.ast.QuerySyntaxException: MIncident is not mapped
  

  While I have annotation @Entity on that class.

  It seems to be correct mapped, but I cant do any operation like hsql select or JPA.em().find() on that entities

  解决方案

  I figure it out on my own.

  Runtime error:

  [IllegalArgumentException: Unknown entity: models.common.AppMode]Is caused by Jpa/Hibernate configuration. Problem is that Jpa/Hibernate sees my entities (mark by annotation @Entity) while compilation, but in runtime dosn't. To fix that I've to manually point all my models class (entitites) in persistance.xml file as follow:

  /conf/META-INF/persistence.xml

  <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_2_0.xsd"
               version="2.0">
  
      <persistence-unit name="defaultPersistenceUnit" transaction-type="RESOURCE_LOCAL">
          <provider>org.hibernate.ejb.HibernatePersistence</provider>
          <non-jta-data-source>DefaultDS</non-jta-data-source>
              <class>models.common.AppMode</class>
              <class>models.Customer</class>
              <class>models.Complaint</class>
          <properties>
              <property name="hibernate.hbm2ddl.auto" value="update"/>
              <property name="hibernate.dialect" value="org.hibernate.dialect.H2Dialect"/>
              <property name="hibernate.show_sql" value="true"/>
          </properties>
      </persistence-unit>
  </persistence>
  

  Original post:package names (namespaces) in subproject classes in Play Framework

  I wonder why in main project (f.e: /app/models/User.java) I can use annotation @javax.persistence.Entity (and it works), but in sub project (f.e: /modules/common/app/models/AppMode.java) it dosnt work, the annotation @javax.persistence.Entity is not enought, I have to point each model class in persistance.xml file.

  I think it is a bug in playframework (I've checked 2.2.1, 2.2.4, and 2.3.4 versions)

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