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Java SpringXML…有条件地加载变量_Java_Spring_Spring Mvc_Jvm - Fatal编程技术网

Java SpringXML…有条件地加载变量

Java SpringXML…有条件地加载变量,java,spring,spring-mvc,jvm,Java,Spring,Spring Mvc,Jvm,我的问题如下 在spring配置中,我希望读取JVM属性。现在,基于JVM属性,我想选择在某个运行时属性中定义的用户名值 比如说, 我定义了一个JVM属性instanceId。它可以有主或次字符串值 另外,我有两个运行时属性 PrimaryAccount=123 SecondaryAccount=456 现在基于jvm属性值 // pseudo code if instanceId = primary Bean ABC should be passed 123 in its cons

我的问题如下

在spring配置中,我希望读取JVM属性。现在,基于JVM属性,我想选择在某个运行时属性中定义的用户名值

比如说,

我定义了一个JVM属性
instanceId
。它可以有
字符串值

另外,我有两个运行时属性

PrimaryAccount=123
SecondaryAccount=456
现在基于jvm属性值

// pseudo code
if instanceId = primary 
    Bean ABC should be passed 123 in its constructor argument 

if instanceId = secondary 
    Bean ABC should be passed 456 in its constructor argument 



  I am trying this 

<constructor-arg> 
  <value>#{ systemProperties['newsAppIndexDataNode'].equals('primary') ? ${instance_primary} :    ${instance_secondary} }</value> 
</constructor-arg> 

使用以下Java配置

@Configuration
public class SomeConfig {

   @Autowired
   private Environment environment;

   @Bean
   public YourBeanType yourBeanType() {
       final String jvmProperty = environment.getProperty("instanceId");
       if(jvmProperty.equals("primary")) {
           return new YourBeanType(123);
       }
       else if(jvmProperty.equals("secondary")) {
           return new YourBeanType(456);
       }

       return new YourBeanType(-1); //return whatever is meaningfull here, or throw an exception

   }
}
编辑

XML配置可能如下所示(由于id未检查“secondary”,因此不完全等效):



您可能需要查看配置文件,例如,请参阅我只需要为一个属性设置一个简单的开关。不想设置显式文件然后直接传递构造函数arg或用户postconstruct{systemProperties['newsAppIndexDataNode'].equals('primary')?${instance_primary}:${instance_secondary}}你能给我这个xml片段吗???@user1700020在你发布的xml中,你在这两种情况下都选择PrimaryAccount。此外,您还需要将PrimaryAccount设置为XML中的某个属性抱歉,我的错误。。。是的,这些值正在从属性文件中读取。但我得到了额外的报价与价值观
@Configuration
public class SomeConfig {

   @Autowired
   private Environment environment;

   @Bean
   public YourBeanType yourBeanType() {
       final String jvmProperty = environment.getProperty("instanceId");
       if(jvmProperty.equals("primary")) {
           return new YourBeanType(123);
       }
       else if(jvmProperty.equals("secondary")) {
           return new YourBeanType(456);
       }

       return new YourBeanType(-1); //return whatever is meaningfull here, or throw an exception

   }
}
<bean class="YourBean">
   <constructor-arg index="0" value="#{systemProperties['instanceId'].equals('primary') ? '456' : '123' }">
</bean>