Spring属性解析Bean与配置

方式1

 <bean id="properties" class="org.springframework.beans.factory.config.PropertiesFactoryBean">
 </bean>
 <!-- spring上下文(XML和注解)中的属性占位符替换 -->
 <context:property-placeholder  properties-ref="properties" trim-values="true"/>

方式2：

<context:property-placeholder location=""xx />

方式3：

<bean class="org.springframework.context.support.PropertySourcesPlaceholderConfigurer">
    <property name ="location" value="xxx">
</bean>

方式4：

Any ${...} placeholders present in a @PropertySource resource location will be resolved against the set of property sources already registered against the environment. For example:
   @Configuration
   @PropertySource("classpath:/com/${my.placeholder:default/path}/app.properties")
   public class AppConfig {
       @Autowired
       Environment env;
       @Bean
       public TestBean testBean() {
           TestBean testBean = new TestBean();
           testBean.setName(env.getProperty("testbean.name"));
           return testBean;
       }
   }