JPA - 禁用persistence.xml的验证 [英] JPA - disable validation of persistence.xml

问题描述

我正在用JPA（Hibernate）迈出第一步。总体思路是连接到传统数据库来完成复杂的查询。我认为，hibernate是这项任务的很好伴侣，但是......一开始，我创建了一个bean，即persistence.xml和hibernate。 cfg.xml配置文件和主要方法中的一些代码行，从以下开始：

  EntityManagerFactory emf = Persistence.createEntityManagerFactory（富）; 
  

它读取persistence.xml文件但，因为我断开连接从互联网上，它无法读取模式文件（xsd）来验证persistence.xml并抱怨异常。 （并且我没有在该环境中的persistence.xsd的本地副本）。我尝试删除schemalocation属性，但这并没有帮助。没有语法，没有JPA！？

有没有一种方法/一个技巧/解决方法来禁用文档验证，至少用于解析persistence.xml？

解决方案

从JPA规范中提取

（Hibernate）必须根据persistence_1_0.xsd模式验证persistence.xml文件并报告任何验证错误

...

持久性配置文件必须通过使用持久性命名空间来指示持久性模式

  http://java.sun.com/xml/ns/persistence 
  
 
lockquote 
 
 并使用版本元素指示模式的版本，如图所示
 
 
 
 
 
 < 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> 
  
上面显示的元素适用于JPA 1.0 正在使用JPA 2.0 
 
I'm taking my first steps with JPA (Hibernate). The overall idea is to connect to a legacy database to do complex queries. I think, hibernate is a great companion for this task, but...

... for a start, I created one bean, the persistence.xml and hibernate.cfg.xml configuration files and some lines of code in a main method, starting with:
EntityManagerFactory emf = Persistence.createEntityManagerFactory("foo");
It reads the persistence.xml file but, because I'm disconnected from the internet, it can't read the schema file (xsd) to validate persistence.xml and complains with exceptions. (And I don't have a local copy of persistence.xsd in that environment). I tried with removing the schemalocation attribute, but that didn't help. No grammar, no JPA!?

Is there a way / a trick / a workaround to disable document validation at least for parsing persistence.xml?
解决方案
Extracted from JPA specification

  
The container/presistence provider (Hibernate) must validate the persistence.xml file against the persistence_1_0.xsd schema and report any validation errors
...

  
Persistence configuration files must indicate the persistence schema by using the persistence namespace


 http://java.sun.com/xml/ns/persistence



  
And indicate the version of the schema by using the version element as shown below


<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">
The element shown above is valid for JPA 1.0 Update to 2.0 if you are using JPA 2.0

                        
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