2

同事们，我有基于 java 的 Spring 配置：

@Configuration
@EnableTransactionManagement
@ComponentScan (basePackages = {"com.abc.dirint"})
@PropertySource("classpath:/settings/${env}/dir.properties")
@EnableScheduling
public class DirConfig {

    private static final Logger log = LoggerFactory.getLogger(DirConfig.class);

    @Autowired
    private Environment environment;

     @Bean
        public static PropertySourcesPlaceholderConfigurer propertyConfigInDev() throws IOException {
            PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer = new PropertySourcesPlaceholderConfigurer();
    propertySourcesPlaceholderConfigurer.setIgnoreUnresolvablePlaceholders(true);
            return propertySourcesPlaceholderConfigurer;
        }


        /*Beans follow...*/ 

        }

当我执行mvn clean package -Denv=dev它运行测试并构建项目时没有任何错误。

现在我想运行已编译的 jar。我执行java -jar dir-integration-1.2-SNAPSHOT.jar -Denv=dev并且程序失败（这是预期的），下一个堆栈跟踪：

Exception in thread "main" org.springframework.beans.factory.BeanDefinitionStoreException: Failed to parse configuration class [com.abc.dirint.DirConfig]; nested exception is java.lang.IllegalArgumentException: Could not resolve placeholder 'env' in string value "classpath:/settings/${env}/dir.properties"
        at org.springframework.context.annotation.ConfigurationClassParser.parse(ConfigurationClassParser.java:180)

Wnen 我运行$ java -jar dir-integration-1.2-SNAPSHOT.jar --env=dev结果是下一个：

Exception in thread "main" org.springframework.beans.factory.BeanDefinitionStoreException: Failed to parse configuration class [com.abc.dirint.DirConfig]; nested exception is java.lang.IllegalArgumentException: Could not resolve placeholder 'env' in string value "classpath:/settings/${env}/dir.properties"
        at org.springframework.context.annotation.ConfigurationClassParser.parse(ConfigurationClassParser.java:180)
        at org.springframework.context.annotation.ConfigurationClassPostProcessor.processConfigBeanDefinitions(ConfigurationClassPostProcessor.java:308)
        at org.springframework.context.annotation.ConfigurationClassPostProcessor.postProcessBeanDefinitionRegistry(ConfigurationClassPostProcessor.java:228)
        at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanDefinitionRegistryPostProcessors(PostProcessorRegistrationDelegate.java:270)
        at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:93)
        at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:686)
        at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:524)
        at org.springframework.context.annotation.AnnotationConfigApplicationContext.<init>(AnnotationConfigApplicationContext.java:84)
        at com.abc.dirint.AdApp.main(AdApp.java:19) Caused by: java.lang.IllegalArgumentException: Could not resolve placeholder 'env' in string value "classpath:/settings/${env}/dir.properties"
        at org.springframework.util.PropertyPlaceholderHelper.parseStringValue(PropertyPlaceholderHelper.java:174)
        at org.springframework.util.PropertyPlaceholderHelper.replacePlaceholders(PropertyPlaceholderHelper.java:126)
        at org.springframework.core.env.AbstractPropertyResolver.doResolvePlaceholders(AbstractPropertyResolver.java:236)
        at org.springframework.core.env.AbstractPropertyResolver.resolveRequiredPlaceholders(AbstractPropertyResolver.java:210)
        at org.springframework.core.env.AbstractEnvironment.resolveRequiredPlaceholders(AbstractEnvironment.java:571)
        at org.springframework.context.annotation.ConfigurationClassParser.processPropertySource(ConfigurationClassParser.java:379)
        at org.springframework.context.annotation.ConfigurationClassParser.doProcessConfigurationClass(ConfigurationClassParser.java:

在应用程序运行期间我应该怎么做才能从指定的属性文件中接收属性？

4

1 回答 1

3

从java -h

Usage: java [-options] class [args...]
           (to execute a class)
   or  java [-options] -jar jarfile [args...]
           (to execute a jar file)
where options include:
...
    -D<name>=<value>
                  set a system property

java -Denv=dev -jar dir-integration-1.2-SNAPSHOT.jar因此，使用提供的系统属性运行 jar 的正确命令应该是

而且，你应该知道，使用mvn ... -Denv=devvsjava -Denv=dev ...是两个完全不同的东西。

使用mvn，占位符替换发生在编译时，这意味着最终的 jar 将包含@PropertySource("classpath:/settings/dev/dir.properties")

但是，您的第二种方法是将占位符保留在已编译的类中，并依靠 Spring 在运行时执行替换

于 2017-03-16T08:42:35.290 回答