Spring import配置文件使用占位符

import使用占位符

连接池切换导入配置的代码:

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<import resource="classpath:META-INF/spring/spring-${db.connection.pool}.xml" />

在配置文件添加配置

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db.connection.pool=druid

启动直接报错,读取不到配置,因为属性文件的加载在import配置文件之后。

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Caused by: java.lang.IllegalArgumentException: Could not resolve placeholder 'db.connection.pool' in value "classpath:META-INF/spring/spring-${db.connection.pool}.xml"

所以,要在应用启动的时候添加属性

1、添加AppContextInitializer启动类:

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public class AppContextInitializer
implements ApplicationContextInitializer<ConfigurableApplicationContext> {

private Logger logger = Logger.getLogger(AppContextInitializer.class);

@Override
public void initialize(ConfigurableApplicationContext applicationContext) {
ResourcePropertySource propertySource = null;
try {
propertySource = new ResourcePropertySource("classpath:config/db-config.properties");
} catch (IOException e) {
logger.error("加载配置文件[config/db-config.properties]失败");
}
applicationContext.getEnvironment().getPropertySources().addFirst(propertySource);
}

}

2、在web.xml中添加配置:

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context-param>  
<param-name>contextInitializerClasses</param-name>
<param-value>com.example.AppContextInitializer</param-value>
</context-param>

启动配置文件加载正常。