如何从文件config.properties中读取persistence.xml <jta-data-source>的标记值</jta-data-source>

Question

我想做这样的事情：

config.properties：

dsname=value;
anotherValue=anotherValue;

persitence.xml

<jta-data-source>${dsname}</jta-data-source>

Answer 1

属性文件在我的web项目之外，我使用JPA和EclipseLink，但我需要从外部文件值“dsname”初始化参数jta-data-source

实际上是：

<persistence-unit name="Unit-ejbPU" transaction-type="JTA">
  <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
    <jta-data-source>datasource</jta-data-source>
      <class>Clase1</class>
      <class>Clase2</class>
      <class>Clase3</class>
  <properties/>
</persistence-unit>

想法：

<persistence-unit name="Unit-ejbPU" transaction-type="JTA">
  <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
    <jta-data-source>${dsname}</jta-data-source>
      <class>Clase1</class>
      <class>Clase2</class>
      <class>Clase3</class>
  <properties/>
</persistence-unit>