[英]Add Bean Programmatically to Spring Web App Context
由于插件架构,我试图以编程方式向我的 web 应用程序添加一个 bean。 我有一个通过@Component
注释创建的 Spring bean,我正在实现ApplicationContextAware
接口。
我的覆盖函数如下所示:
@Override
public void setApplicationContext(ApplicationContext applicationContext)
throws BeansException {
// this fails
this.applicationContext = (GenericWebApplicationContext) applicationContext;
}
基本上,我无法弄清楚如何将 bean 添加到给定 setApplicationContext 的 applicationContext 对象中。 谁能告诉我我是如何以错误的方式解决这个问题的?
好的,这就是我最终得到的解决方案:
@Override
public void postProcessBeanDefinitionRegistry(BeanDefinitionRegistry bdr)
throws BeansException {
BeanDefinition definition = new RootBeanDefinition(
<My Class>.class);
bdr.registerBeanDefinition("<my id>", definition);
}
这是一个简单的代码:
ConfigurableListableBeanFactory beanFactory = ((ConfigurableApplicationContext) applicationContext).getBeanFactory();
beanFactory.registerSingleton(bean.getClass().getCanonicalName(), bean);
在 Spring 3.0 中,您可以让 bean 实现BeanDefinitionRegistryPostProcessor
并通过BeanDefinitionRegistry
添加新 bean。
在以前的 Spring 版本中,您可以在BeanFactoryPostProcessor
执行相同的操作(尽管您需要将BeanFactory
为BeanDefinitionRegistry
,这可能会失败)。
为什么你需要它是GenericWebApplicationContext
类型?
我认为您可能可以使用任何 ApplicationContext 类型。
通常你会使用一个 init 方法(除了你的 setter 方法):
@PostConstruct
public void init(){
AutowireCapableBeanFactory bf = this.applicationContext
.getAutowireCapableBeanFactory();
// wire stuff here
}
你可以使用任何一种来连接 bean
AutowireCapableBeanFactory.autowire(Class, int mode, boolean dependencyInject)
或者
AutowireCapableBeanFactory.initializeBean(Object existingbean, String beanName)
实际上AnnotationConfigApplicationContext
派生自AbstractApplicationContext
,它有空的postProcessBeanFactory
方法留给覆盖
/**
* Modify the application context's internal bean factory after its standard
* initialization. All bean definitions will have been loaded, but no beans
* will have been instantiated yet. This allows for registering special
* BeanPostProcessors etc in certain ApplicationContext implementations.
* @param beanFactory the bean factory used by the application context
*/
protected void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) {
}
为了利用这一点,创建AnnotationConfigApplicationContextProvider
类,它可能如下所示(对于Vertx
实例示例,您可以改用MyClass
)...
public class CustomAnnotationApplicationContextProvider {
private final Vertx vertx;
public CustomAnnotationApplicationContextProvider(Vertx vertx) {
this.vertx = vertx;
}
/**
* Register all beans to spring bean factory
*
* @param beanFactory, spring bean factory to register your instances
*/
private void configureBeans(ConfigurableListableBeanFactory beanFactory) {
beanFactory.registerSingleton("vertx", vertx);
}
/**
* Proxy method to create {@link AnnotationConfigApplicationContext} instance with no params
*
* @return {@link AnnotationConfigApplicationContext} instance
*/
public AnnotationConfigApplicationContext get() {
return new AnnotationConfigApplicationContext() {
@Override
protected void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) {
super.postProcessBeanFactory(beanFactory);
configureBeans(beanFactory);
}
};
}
/**
* Proxy method to call {@link AnnotationConfigApplicationContext#AnnotationConfigApplicationContext(DefaultListableBeanFactory)} with our logic
*
* @param beanFactory bean factory for spring
* @return
* @see AnnotationConfigApplicationContext#AnnotationConfigApplicationContext(DefaultListableBeanFactory)
*/
public AnnotationConfigApplicationContext get(DefaultListableBeanFactory beanFactory) {
return new AnnotationConfigApplicationContext(beanFactory) {
@Override
protected void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) {
super.postProcessBeanFactory(beanFactory);
configureBeans(beanFactory);
}
};
}
/**
* Proxy method to call {@link AnnotationConfigApplicationContext#AnnotationConfigApplicationContext(Class[])} with our logic
*
* @param annotatedClasses, set of annotated classes for spring
* @return
* @see AnnotationConfigApplicationContext#AnnotationConfigApplicationContext(Class[])
*/
public AnnotationConfigApplicationContext get(Class<?>... annotatedClasses) {
return new AnnotationConfigApplicationContext(annotatedClasses) {
@Override
protected void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) {
super.postProcessBeanFactory(beanFactory);
configureBeans(beanFactory);
}
};
}
/**
* proxy method to call {@link AnnotationConfigApplicationContext#AnnotationConfigApplicationContext(String...)} with our logic
*
* @param basePackages set of base packages for spring
* @return
* @see AnnotationConfigApplicationContext#AnnotationConfigApplicationContext(String...)
*/
public AnnotationConfigApplicationContext get(String... basePackages) {
return new AnnotationConfigApplicationContext(basePackages) {
@Override
protected void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) {
super.postProcessBeanFactory(beanFactory);
configureBeans(beanFactory);
}
};
}
}
在创建ApplicationContext
您可以使用
Vertx vertx = ...; // either create or for vertx, it'll be passed to main verticle
ApplicationContext context = new CustomAnnotationApplicationContextProvider(vertx).get(ApplicationSpringConfig.class);
首先初始化属性值
MutablePropertyValues mutablePropertyValues = new MutablePropertyValues();
mutablePropertyValues.add("hostName", details.getHostName());
mutablePropertyValues.add("port", details.getPort());
DefaultListableBeanFactory context = new DefaultListableBeanFactory();
GenericBeanDefinition connectionFactory = new GenericBeanDefinition();
connectionFactory.setBeanClass(Class);
connectionFactory.setPropertyValues(mutablePropertyValues);
context.registerBeanDefinition("beanName", connectionFactory);
添加到bean列表
ConfigurableListableBeanFactory beanFactory = ((ConfigurableApplicationContext) applicationContext).getBeanFactory();
beanFactory.registerSingleton("beanName", context.getBean("beanName"));
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