具有动态构造函数值的Spring bean [英] spring bean with dynamic constructor value

问题描述

我需要创建一个没有构造函数参数的不完整对象.像这样

I need to create an Object which is in-complete without the constructor argument. Something like this

Class A  {
  private final int timeOut
  public A(int timeout)
  {
     this.timeOut = timeout;
   }
 //...
}

我希望这个Bean是Spring管理的，以便以后可以使用Spring AOP.

I would like this Bean to be spring managed, so that I can use Spring AOP later.

<bean id="myBean" class="A" singleton="false">
</bean>

但是我的bean需要将超时作为动态值传递-有没有一种方法可以创建在构造函数中注入了动态值的spring托管bean?

However my bean needs timeout to be passed as a dynamic value - is there a way to create a spring managed bean with dynamic value being injedcted in the constructor?

推荐答案

BeanFactory具有getBean(String name, Object... args)方法，根据

BeanFactory has a getBean(String name, Object... args) method which, according to the javadoc, allows you to specify constructor arguments which are used to override the bean definition's own arguments. So you could put a default value in the beans file, and then specify the "real" runtime values when required, e.g.

<bean id="myBean" class="A" scope="prototype">
   <constructor-arg value="0"/> <!-- dummy value -->
</bean>

然后:

getBean("myBean", myTimeoutValue);

我还没有尝试过，但是应该可以.

I haven't tried this myself, but it should work.

P.S. scope="prototype"现在比singleton="false"更可取，后者已被弃用-更加明确，但功能相同.

P.S. scope="prototype" is now preferable to singleton="false", which is deprecated syntax - it's more explicit, but does the same thing.

这篇关于具有动态构造函数值的Spring bean的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！