What is the easiest way to change the prefix and suffix for the property placeholder in Spring Boot?
The default is @Value("${some.property}"), however this looks ugly in Kotlin, since it needs to be escaped - ${something} is a language feature in Kotlin for String templates.
通过在配置中声明以下bean，可以自定义使用的前缀:
@Bean
fun propertyConfigurer() = PropertySourcesPlaceholderConfigurer().apply {
setPlaceholderPrefix("%{")
}
如果您有任何使用${...}语法的现有代码(如Spring Boot actuators或@LocalServerPort)，您应该声明:
@Bean
fun kotlinPropertyConfigurer() = PropertySourcesPlaceholderConfigurer().apply {
setPlaceholderPrefix("%{")
setIgnoreUnresolvablePlaceholders(true)
}
@Bean
fun defaultPropertyConfigurer() = PropertySourcesPlaceholderConfigurer()
Escaping the dollar like in @Value("\${some.property}") is another possible option that require no @Bean declaration.
对于配置为@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)的Spring Boot测试，可以使用@LocalServerPort而不是@Value("\${local.server.port}").
@ConfigurationProperties将是一个更好的 Select ，尤其是对于Kotlin数据类，但目前必须使用具有可为null的var属性的Kotlin类，因为只支持getter/setter.你可以投票支持this issue或发表 comments ，以表明你有兴趣在Spring Boot 2中获得支持.十、