以编程方式检索Bean [英] retrieve Bean programmatically

问题描述

@Configuration
public class MyConfig {
    @Bean(name = "myObj")
    public MyObj getMyObj() {
        return new MyObj();
    }
}

我有一个带有@Configuration Spring批注的MyConfig对象. 我的问题是，如何才能以编程方式(在常规类中)检索Bean?

I have this MyConfig object with @Configuration Spring annotation. My question is that how I can retrieve the bean programmatically (in a regular class)?

例如，代码段如下所示. 预先感谢.

for example, the code snippet looks like this. Thanks in advance.

public class Foo {
    public Foo(){
    // get MyObj bean here
    }
}

public class Var {
    public void varMethod(){
            Foo foo = new Foo();
    }
}

推荐答案

此处是示例

public class MyFancyBean implements ApplicationContextAware {

  private ApplicationContext applicationContext;

  void setApplicationContext(ApplicationContext applicationContext) {
    this.applicationContext = applicationContext;
  }

  public void businessMethod() {
    //use applicationContext somehow
  }

}

但是，您几乎不需要直接访问ApplicationContext.通常，您只需启动一次，然后让Bean自动填充自己.

However you rarely need to access ApplicationContext directly. Typically you start it once and let beans populate themselves automatically.

您在这里:

ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");

请注意，您不必提及applicationContext.xml中已经包含的文件.现在，您只需按名称或类型获取一个bean:

Note that you don't have to mention files already included in applicationContext.xml. Now you can simply fetch one bean by name or type:

ctx.getBean("someName")

请注意，有很多启动Spring的方法-使用ContextLoaderListener，@ Configuration类等.

Note that there are tons of ways to start Spring - using ContextLoaderListener, @Configuration class, etc.

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