metamodel

I am building a code generator in XTend where I already have an input model and meta model. That is, I use ATL to generate the input model for my XTend code generator (as part of a transformation sequence to gradually lower the abstraction level, instead of at once; this is the reason i'm not using xtext to create the syntax). So to be very clear, my input model for the code generator is a file in XMI format and NOT in the grammar of the xtext project (not even using that)! And i think this is causing me problems/confusion. I created a new XText project using Existing models, right clicked on

Hibernate 项目小组提供了一系列发布组合（bundles），这些发布组合发布在 SourceForge 文件发布系统中。这些发布的包有 TGZ 和ZIP 格式。 每一个发布组合包含有 JAR 文件，文档，源代码和其他一些有用的内容。 你可以选择你需要的格式来下载 Hibernate 的发布版本，有关发布版本的列表，请参考 https://sourceforge.net/projects/hibernate/files/hibernate-orm/ 。发布版本的结构请参考下面的内容： lib/required/ 目录包含有 hibernate-core Jar 和所有需要的依赖。不管你需要使用 Hibernate 的何种功能，所有的这些都需要设置到你的 classpath 路径中。 lib/envers 目录包含有 hibernate-envers Jar 和需要的依赖（这些依赖，不包含在 lib/required/ 和lib/jpa/ 中）。 lib/spatial/ 目录包含有 hibernate-spatial Jar 和需要的依赖（这些依赖，不包含在 lib/required/ 和lib/jpa/ 中）。 lib/osgi/ 目录包含有 hibernate-osgi Jar 和需要的依赖（这些依赖，不包含在 lib/required/ 和lib/jpa/ 中）。

I'm using hibernate-jpamodelgen to generate the metamodel classes using maven. When i run mvn clean package , it works fine without any problem. But if i run the mvn package second time (without clean), I'm getting the following exception : An exception has occurred in the compiler (1.8.0_51). Please file a bug at the Java Developer Connection (http://java.sun.com/webapps/bugreport) after checking the Bug Parade for duplicates. Include your program and the following diagnostic in your report. Thank you. java.lang.IllegalStateException: endPosTable already set at com.sun.tools.javac.util

概述 软件开发模型(Software Development Model)是指软件开发全部过程、活动和任务的结构框架。软件开发包括需求、设计、编码、测试和维护阶段。 软件开发模型能清晰、直观地表达软件开发全过程，明确规定了要完成的主要活动和任务，用来作为软件项目工作的基础。对于不同的软件系统，可以采用不同的开发方法、使用不同的程序设计语言以及各种不同技能的人员参与工作、运用不同的管理方法和手段等，以及允许采用不同的软件工具和不同的软件工程环境。 最早出现的软件开发模型是1970年W·Royce提出的瀑布模型。该模型给出了固定的顺序，将生存期活动从上一个阶段向下一个阶段逐级过渡，如同流水下泻，最终得到所开发的软件产品，投入使用。但计算拓广到统计分析、商业事务等领域时，大多数程序采用高级语言(如FORTRAN、COBOL等)编写。瀑布模式模型也存在着缺乏灵活性、无法通过并发活动澄清本来不够确切的需求等缺点。 常见的软件开发模型还有演化模型、螺旋模型、喷泉模型、智能模型等。 典型的开发模型 1. 边做边改模型（Build-and-Fix Model）； 2. 瀑布模型（Waterfall Model）； 3. 快速原型模型（Rapid Prototype Model）； 4. 增量模型（Incremental Model）； 5. 螺旋模型（Spiral Model）； 6. 演化模型

I have just used org.apache.openjpa.persistence.meta.AnnotationProcessor6 to generate the MetaModel for my JPA2 entities. @javax.annotation.Generated (value="org.apache.openjpa.persistence.meta.AnnotationProcessor6", date="Tue Nov 22 09:49:03 CET 2011") public class Entity_ { public static volatile SingularAttribute<Entity,Entity> id; public static volatile SingularAttribute<Entity,String> value; public static volatile SingularAttribute<Entity,String> order; } Can someone please explain why the attributes are marked volatile in this case? Thanks. The thread that sets the static variables might

Given a Django model, I'm trying to list all of its fields. I've seen some examples of doing this using the _meta model attribute, but doesn't the underscore in front of meta indicate that the _meta attribute is a private attribute and shouldn't be accessed directly? ... Because, for example, the layout of _meta could change in the future and not be a stable API? Is _meta an exception to this rule? Is it stable and ready to use or is it considered bad practice to access it? Or is there a function or some other way to introspect the fields of a model without using the _meta attribute? Below is

In the spirit of type safety associated with the CriteriaQuery JPA 2.0 also has an API to support Metamodel representation of entities. Is anyone aware of a fully functional implementation of this API (to generate the Metamodel as opposed to creating the metamodel classes manually)? It would be awesome if someone also knows the steps for setting this up in Eclipse (I assume it's as simple as setting up an annotation processor, but you never know). EDIT: Just stumbled across Hibernate JPA 2 Metamodel Generator . But the issue remains since I can't find any download links for the jar. EDIT 2: