java如何使用applicationContext中的嵌套属性构造bean。xml？

Question

我有这样的Java类：

public class Config {
    public Config1 getConfigOpt1();
    public Config2 getConfigOpt2();
}

public class SomeBean {
    public Config getEntireConfig();
}

public class BeanToConstruct {

    public static BeanToConstruct createAndStart( Config1 config1, Config2 config2 )
}

给定SomeBean，我会这样构造BeanToConstruction：

SomeBean someBean = ....
BeanToConstruct bean = BeanToConstruct.createAndStart( 
    someBean.getEntireConfig().getConfigOpt1(),
    someBean.getEntireConfig().getConfigOpt2() )

如何在applicationContext中实现这一点。xml？这基本上就是我想做的，但显然行不通。我可以把整个配置对象拉到它自己的bean中，但我不想有这个额外的bean，它只需要让构建BeanToConstruct成为可能

<bean class="com.example.SomeBean" id="someBean"/>
<bean class="com.example.BeanToConstruct" factory-method="createAndStart" id="myBean">
    <constructor-arg>
        <bean factory-bean="someBean" factory-method="getEntireConfig().getConfigOpt1()"/>
    </constructor-arg>
    <constructor-arg>
        <bean factory-bean="someBean" factory-method="getEntireConfig().getConfigOpt2()"/>
    </constructor-arg>
</bean> 

Answer 1

春天3号。你可以使用expression language：

<bean class="com.example.BeanToConstruct" factory-method="createAndStart" id="myBean"> 
    <constructor-arg value = "#{someBean.entireConfig.configOpt1}" /> 
    <constructor-arg value = "#{someBean.entireConfig.configOpt2}" /> 
</bean> 

Answer 2

我认为您可以使用util:property path来实现：

<beans xmlns="http://www.springframework.org/schema/beans"
   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
   xmlns:util="http://www.springframework.org/schema/util"
   xsi:schemaLocation="
   http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd
   http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-2.0.xsd">

...

<bean class="com.example.SomeBean" id="someBean"/>
<bean class="com.example.BeanToConstruct" factory-method="createAndStart" id="myBean">
    <constructor-arg>
        <util:property-path path="someBean.entireConfig.configOpt1"/>
    </constructor-arg>
    <constructor-arg>
        <util:property-path path="someBean.entireConfig.configOpt2"/>
    </constructor-arg>
</bean>

....
</beans>