Spring获取bean的工具类

通过注解的方式获取bean

<!-- 扫描所有Servcie类 -->
	<context:component-scan base-package="com.cnten.**.service" />

通过类名获取实例化的bean

@Service
public class PortalService {

}

PortalService portalService = (PortalService) applicationContext.getBean("PortalService");

spring应用的上下文环境

import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;

public class ApplicationContextAwareUtil implements ApplicationContextAware {
	private static ApplicationContext applicationContext;

	@Override
	public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
		this.applicationContext = applicationContext;
	}

	public static ApplicationContext getApplicationContext() {
		return applicationContext;
	}

  public static <T> T getBean(String name)
  {
    return applicationContext.getBean(name);
  }
  
  public static <T> T getBean(Class<T> clazz)
  {
    return applicationContext.getBeansOfType(clazz);
  }

}

通过实现了InitializingBean接口获取bea

获取bean的工具类

import org.springframework.beans.factory.InitializingBean;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.ConfigurableApplicationContext;

public class SpringContextHolder
  implements ApplicationContextAware, InitializingBean
{
  private static ConfigurableApplicationContext applicationContext;
  
  public void setApplicationContext(ApplicationContext applicationContext)
  {
    applicationContext = (ConfigurableApplicationContext)applicationContext;
  }
  
  public static ApplicationContext getApplicationContext()
  {
    checkApplicationContext();
    return applicationContext;
  }
  
  public static <T> T getBean(String name)
  {
    checkApplicationContext();
    return applicationContext.getBean(name);
  }
  
  public static <T> T getBean(Class<T> clazz)
  {
    checkApplicationContext();
    return applicationContext.getBeansOfType(clazz);
  }
  
  private static void checkApplicationContext()
  {
    if (applicationContext == null) {
      throw new IllegalStateException("applicaitonContext未注入,请在applicationContext.xml中定义SpringContextHolder");
    }
  }
  
  public void afterPropertiesSet()
    throws Exception
  {}
}

<bean id="cacheManager" class="net.sf.ehcache.CacheManager" lazy-init="false"/>
<bean id="ehCacheManagerImpl" class="com.cache.EhCacheManagerImpl" lazy-init="false"/>

<!-- bean 管理器 -->
	<bean id="springContextHolder" class="com.context.SpringContextHolder" lazy-init="false"/>

public class EhCacheManagerImpl
{
  public static final CacheManager cacheManager = (CacheManager)SpringContextHolder.getBean("cacheManager");
}

实例化bean

	@Autowired
	private EhCacheManagerImpl ehCaheMamger;

实现了InitializingBean接口，会自动调用afterPropertiesSet方法。

@Component("initializingService")
public class InitializingServiceImpl implements InitializingBean {

    @Override
    public void afterPropertiesSet() throws Exception {
        
        System.out.println("call InitializingBean");
    }

}

获取bean上下文工具类实现

public class SpringContextUtil implements ApplicationContextAware {

    private static ApplicationContext applicationContext; // Spring应用上下文环境

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        SpringContextUtil.applicationContext = applicationContext;
    }

    /**
     * 获取对象
     * 
     * @param name
     * @return Object 实例
     * @throws BeansException
     */
    public static Object getBean(String name) throws BeansException {
        return applicationContext.getBean(name);
    }

}

<bean id="springContextUtil" class="com.aop.SpringContextUtil" />

public class InitializingBeanDemo {

    public static void main(String[] args) {
        new ClassPathXmlApplicationContext("spring.xml"); // 加载ApplicationContext（模拟启动web服务）

        InitializingService service = (InitializingService) SpringContextUtil.getBean("initializingService");
    }
}

返回

call InitializingBean