Spring 如何在字符串中插入 ${x}？
How does Spring interpolate ${x} inside a string?
我在 Spring 项目中有一个 java class，看起来（已编辑）如下：
@Component
public class X
{
private static final ApplicationContext CTX = new FileSystemXmlApplicationContext("file:${PATH}/ApplicationContext.xml");
...
我正在寻找解释如何在字符串参数中插入 ${PATH} 的参考资料。 PATH 作为系统 属性 ( java -DPATH=...) 传递，所以我假设它是从那里获取的，但我找不到描述该机制的解释。它是一个与@Value 中使用的语法相似的 Spring 相关功能吗？
configLocations（类型 String）传递给 FileSystemXmlApplicationContext constructors are processed by the resolvePath() method inherited from the AbstractRefreshableConfigApplicationContext class.
之一
resolvePath() 文档说：
Resolve the given path, replacing placeholders with corresponding environment property values if necessary. Applied to config locations.
See Also:
PropertyResolver.resolveRequiredPlaceholders(String)
resolveRequiredPlaceholders() 文档说：
Resolve ${...} placeholders in the given text, replacing them with corresponding property values as resolved by getProperty(java.lang.String). Unresolvable placeholders with no default value are ignored and passed through unchanged.
PropertyResolver declaring that getProperty() method is actually a StandardEnvironment.
StandardEnvironment 文档说：
Environment implementation suitable for use in 'standard' (i.e. non-web) applications.
In addition to the usual functions of a ConfigurableEnvironment such as property resolution and profile-related operations, this implementation configures two default property sources, to be searched in the following order:
我在 Spring 项目中有一个 java class，看起来（已编辑）如下：
@Component
public class X
{
private static final ApplicationContext CTX = new FileSystemXmlApplicationContext("file:${PATH}/ApplicationContext.xml");
...
我正在寻找解释如何在字符串参数中插入 ${PATH} 的参考资料。 PATH 作为系统 属性 ( java -DPATH=...) 传递，所以我假设它是从那里获取的，但我找不到描述该机制的解释。它是一个与@Value 中使用的语法相似的 Spring 相关功能吗？
configLocations（类型 String）传递给 FileSystemXmlApplicationContext constructors are processed by the resolvePath() method inherited from the AbstractRefreshableConfigApplicationContext class.
resolvePath() 文档说：
Resolve the given path, replacing placeholders with corresponding environment property values if necessary. Applied to config locations.
See Also:
PropertyResolver.resolveRequiredPlaceholders(String)
resolveRequiredPlaceholders() 文档说：
Resolve
${...}placeholders in the given text, replacing them with corresponding property values as resolved bygetProperty(java.lang.String). Unresolvable placeholders with no default value are ignored and passed through unchanged.
PropertyResolver declaring that getProperty() method is actually a StandardEnvironment.
StandardEnvironment 文档说：
Environmentimplementation suitable for use in 'standard' (i.e. non-web) applications.In addition to the usual functions of a
ConfigurableEnvironmentsuch as property resolution and profile-related operations, this implementation configures two default property sources, to be searched in the following order: