Question

我有以下基于Spring XML的配置：

<!--
  These properties define the db.type property.
-->
<bean class="org.springframework.context.support.PropertySourcesPlaceholderConfigurer">
  <property name="order" value="1"/>
  <property name="ignoreUnresolvablePlaceholders" value="true" />
  <property name="ignoreResourceNotFound" value="true" />
  <property name="locations">
    <list>
      <!-- contains default db.type -->
      <value>classpath:/default-cfg.properties</value>
      <!-- db.type can be overridden by optional properties in the app work dir -->
      <value>file:${app.work.dir}/cfg.properties</value>
    </list>
  </property>
</bean>

<!-- db.type should be used to get DB specific config properties -->
<bean class="org.springframework.context.support.PropertySourcesPlaceholderConfigurer">
  <property name="order" value="2"/>
  <property name="ignoreUnresolvablePlaceholders" value="false" />
  <property name="ignoreResourceNotFound" value="false" />
  <property name="locations">
    <list>
      <!-- does not work, ${db.type} does not get resolved -->
      <value>classpath:/default-cfg-${db.type}.properties</value>
    </list>
  </property>
</bean>

问题是，即使第一个属性占位符配置器定义了classpath:/default-cfg-${db.type}.properties，db.type位置中的属性也无法解析。

我在日志中不断收到以下错误：

 class path resource [default-cfg-${db.type}.properties] cannot be opened because it does not exist

有没有办法在PropertyPlaceholderConfigurer的locations属性中使用属性？我想避免使用JVM系统属性来设置db.type值。

谢谢你，扬

Answer 1

由于Alireza Fattahi要求我的代码和WornOutSoles建议接受的解决方案无法正常工作，我发布了基于Spring ApplicationContextInitializer的最终解决方案：

public class SpringProfilesActivator
    implements ApplicationContextInitializer<XmlWebApplicationContext>
{
  private static final Logger log = LoggerFactory.getLogger( SpringProfilesActivator.class );

  ...

  @Override
  public void initialize( XmlWebApplicationContext applicationContext )
  {
    // TODO: get your profiles from somewhere (config files, JVM system properties, database etc.)
    String[] activeProfiles = new String[] { ... };

    log.info( "Activating Spring profiles: {}", Arrays.toString( activeProfiles ) );

    ConfigurableEnvironment env = applicationContext.getEnvironment();
    env.setActiveProfiles( activeProfiles );
  }

  ...
}

Answer 2

两个后处理器都被实例化，orderer然后执行，因此第二个PSPC在第一个PSPC被执行之前被实例化。

如果您的第一个BeanDefinitionRegistryPostProcessor实现public class BeanDefinitionRegistryPlaceholderConfigurer extends PropertySourcesPlaceholderConfigurer implements BeanDefinitionRegistryPostProcessor { @Override public void postProcessBeanDefinitionRegistry(BeanDefinitionRegistry registry) throws BeansException { // nothing todo, just to run before other PPHCs are instantiated } }将在第二个实例化之前运行，并且可以按预期工作。

例如：

{{1}}

Spring PropertyPlaceholderConfigurer具有动态位置路径

2 个答案: