Spring-@Value获取配置文件内容

<bean id="configuration" class="org.springframework.beans.factory.config.PropertiesFactoryBean">  
    <property name="locations">  
        <list>  
            <value>classpath:configuration.properties</value>  
        </list>  
    </property>  
</bean>

@Component  
public class ValueDemo {  
    @Value("#{configuration['key']}")  
    private String value;  
  
    public String getValue() {  
        return value;  
    }  
}

 或者带默认值

@Component  
public class ValueDemo {  
    @Value("#{ @configuration['key'] ?: 'helloworld' }")private String value;  
  
    public String getValue() {  
        return value;  
    }  
}  

 或者默认值是某个类的静态变量

@Component  
public class ValueDemo {  
    @Value("#{ @configuration['key'] ?: T(org.apache.shiro.web.servlet.SimpleCookie).DEFAULT_MAX_AGE}")
    private String value;  
  
    public String getValue() {  
        return value;  
    }  
}