java Spring 占位符不解析 JavaConfig 中的属性
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Spring placeholder doesn't resolve properties in JavaConfig
提问by herau
Currently i have a Spring xml configuration (Spring 4) which load a properties file.
目前我有一个加载属性文件的 Spring xml 配置（Spring 4）。
context.properties
上下文属性
my.app.service = myService
my.app.other = ${my.app.service}/sample
Spring xml configuration
Spring xml 配置
<bean id="contextProperties" class="org.springframework.beans.factory.config.PropertiesFactoryBean">
<property name="ignoreResourceNotFound" value="true" />
<property name="fileEncoding" value="UTF-8" />
<property name="locations">
<list>
<value>classpath:context.properties</value>
</list>
</property>
</bean>
<bean id="placeholder" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="ignoreResourceNotFound" value="true" />
<property name="properties" ref="contextProperties" />
<property name="nullValue" value="@null" />
<property name="systemPropertiesModeName" value="SYSTEM_PROPERTIES_MODE_OVERRIDE" />
</bean>
Bean which use the properties
使用属性的Bean
@Component
public class MyComponent {
@Value("${my.app.other}")
private String others;
}
This works perfectly and the othersvalue is MyService/sample, as excepted. But when i try to replace this configuration by a JavaConfig, the @Valuein my component doesn't works in the same way. the value isn't myService/samplebut ${my.app.service}/sample.
这完美地工作并且others值是MyService/sample，作为例外。但是当我尝试用 JavaConfig 替换此配置时@Value，我的组件中的工作方式不同。值不是myService/sample但是${my.app.service}/sample。
@Configuration
@PropertySource(name="contextProperties", ignoreResourceNotFound=true, value={"classpath:context.properties"})
public class PropertiesConfiguration {
@Bean
public static PropertyPlaceholderConfigurer placeholder() throws IOException {
PropertyPlaceholderConfigurer placeholder = new PropertyPlaceholderConfigurer();
placeholder.setNullValue("@null");
placeholder.setSystemPropertiesMode(PropertyPlaceholderConfigurer.SYSTEM_PROPERTIES_MODE_OVERRIDE);
return placeholder;
}
}
Did i miss something in the conversion from xml to Javaconfig ?
我在从 xml 到 Javaconfig 的转换中遗漏了什么吗？
ps : I also try to instantiate a PropertySourcesPlaceholderConfigurerinstead of a PropertyPlaceholderConfigurerwithout more success.
ps：我也尝试实例化 aPropertySourcesPlaceholderConfigurer而不是 aPropertyPlaceholderConfigurer没有更多的成功。
采纳答案by Mithun
Update to use configure PropertySourcesPlaceholderConfigurer. Just having @PropertySourceannotation will not be sufficient:
更新以使用 configure PropertySourcesPlaceholderConfigurer。仅仅有@PropertySource注释是不够的：
@Bean
public static PropertySourcesPlaceholderConfigurer properties() {
return new PropertySourcesPlaceholderConfigurer();
}
@PropertySourceannotation does not automatically register a PropertySourcesPlaceholderConfigurerwith Spring. Hence we need to explicitly configure PropertySourcesPlaceholderConfigurer
@PropertySource注解不会自动PropertySourcesPlaceholderConfigurer向 Spring注册 a 。因此我们需要显式配置PropertySourcesPlaceholderConfigurer
Below JIRA ticket has more information on the rationale behind this design:
下面 JIRA 票有更多关于这种设计背后的基本原理的信息：
https://jira.spring.io/browse/SPR-8539
https://jira.spring.io/browse/SPR-8539
UPDATE:Created simple Spring boot application to use nested properties. It is working fine with the above configuration.
更新：创建了简单的 Spring Boot 应用程序以使用嵌套属性。使用上述配置可以正常工作。
https://github.com/mgooty/property-configurer/tree/master/complete
https://github.com/mgooty/property-configurer/tree/master/complete
回答by Alfredo Diaz
Another option is to import PropertyPlaceholderAutoConfiguration.class.
另一种选择是导入 PropertyPlaceholderAutoConfiguration.class。
import org.springframework.boot.autoconfigure.PropertyPlaceholderAutoConfiguration;
@Import(PropertyPlaceholderAutoConfiguration.class)
The annotation includes a PropertySourcesPlaceholderConfigurer in the context if it doesn't exist.
如果不存在，则注释在上下文中包含一个 PropertySourcesPlaceholderConfigurer。
