在春季访问缓存的ApplicationContext

Question

I need to fetch a singleton bean from same ApplicationContext twice in 2 different classes.

Example snippet :

CLass A {
  public void foo(){
    ApplicationContext context = new ClassPathXmlApplicationContext("common.spring.xml");
    MyParametrizedSingletonClass myParametrizedSingletonClass = (MyParametrizedSingletonClass) context.getBean("myParametrizedSingletonClass");
    // do more stuff..
  }
CLass B {
  public void bar(){
    ApplicationContext context = new ClassPathXmlApplicationContext("common.spring.xml");
    MyParametrizedSingletonClass myParametrizedSingletonClass = (MyParametrizedSingletonClass) context.getBean("myParametrizedSingletonClass");
    // do more stuff..
  }

Since MyParametrizedSingletonClass is a singletom it if its constructor is called more than once for same constructor arguments it throws error.

How do I cache and reuse ApplicationContext with spring?

Answer 1

You are creating two different context, so even if bean is singleton it will create single instance per context,

if you want to cache application context you can create a class and provide singleton instance of application context

Answer 2

Autowire the bean.

By default the spring injects the autowired beans into required classes and these beans are not created an new everytime. They are singleton by default.

Answer 3

在bean名称myParametrizedSingletonClass的common.spring.xml文件中，在xml文件中定义bean的同时，将范围单例作为参数添加到其中