代码获取Spring注解的bean

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  • Post category:其他




方法一  不用配置xml,直接java代码实现




public class GetApplicationContext {


	private static class ApplicationContextHolder {
		// 单例变量
		private static ApplicationContext AC = new FileSystemXmlApplicationContext(
				"classpath:applicationContext.xml");
	}


	// 私有化的构造方法,保证外部的类不能通过构造器来实例化。
	private GetApplicationContext() {


	}


	// 获取单例对象实例
	public static ApplicationContext getInstance() {
		if (ApplicationContextHolder.AC == null) {
			ApplicationContextHolder.AC = new FileSystemXmlApplicationContext(
					"classpath:applicationContext.xml");
		}
		return ApplicationContextHolder.AC;
	}
}



获取所有spring自动装配的bean;

<span style="font-size:18px;">//获取spring装配的bean个数
GetApplicationContext.getInstance().getBeanDefinitionNames().length;
//逐个打印出spring自动装配的bean。根据我的测试,类名第一个字母小写即bean的名字
for(int i=0;i<33;i++){
	System.out.println( GetApplicationContext.getInstance().getBeanDefinitionNames()[i]);
}</span>



然后通过下面的代码获取到spring注解装配的bean供自己使用

<span style="font-size:18px;">StorageReturnService ossService = (StorageReturnService) GetApplicationContext.getInstance().getBean("storageReturnServiceImpl");</span>










方法二 实现ApplicationContextAware

一定要在

spring

.xml中加上:

<bean id=”

Spring

ContextUtil ” class=”com.am.oa.commons.service.

Spring

ContextUtil ” singleton=”true” />

当对

Spring

ContextUtil 实例时就自动设置applicationContext,以便后来可直接用applicationContext



<span style="font-size:18px;">public class SpringContextUtil implements ApplicationContextAware {
  private static ApplicationContext applicationContext;     //Spring应用上下文环境
 
  /**
  * 实现ApplicationContextAware接口的回调方法,设置上下文环境   
  * @param applicationContext
  * @throws BeansException
  */
  public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
    SpringContextUtil.applicationContext = applicationContext;
  }
 
  /**
  * @return ApplicationContext
  */
  public static ApplicationContext getApplicationContext() {
    return applicationContext;
  }
 
  /**
  * 获取对象   
  * @param name
  * @return Object 一个以所给名字注册的bean的实例
  * @throws BeansException
  */
  public static Object getBean(String name) throws BeansException {
    return applicationContext.getBean(name);
  }
 
  /**
  * 获取类型为requiredType的对象
  * 如果bean不能被类型转换,相应的异常将会被抛出(BeanNotOfRequiredTypeException)
  * @param name       bean注册名
  * @param requiredType 返回对象类型
  * @return Object 返回requiredType类型对象
  * @throws BeansException
  */
  public static Object getBean(String name, Class requiredType) throws BeansException {
    return applicationContext.getBean(name, requiredType);
  }
 
  /**
  * 如果BeanFactory包含一个与所给名称匹配的bean定义,则返回true 
  * @param name
  * @return boolean
  */
  public static boolean containsBean(String name) {
    return applicationContext.containsBean(name);
  }
 
  /**
  * 判断以给定名字注册的bean定义是一个singleton还是一个prototype。
  * 如果与给定名字相应的bean定义没有被找到,将会抛出一个异常(NoSuchBeanDefinitionException)   
  * @param name
  * @return boolean
  * @throws NoSuchBeanDefinitionException
  */
  public static boolean isSingleton(String name) throws NoSuchBeanDefinitionException {
    return applicationContext.isSingleton(name);
  }
 
  /**
  * @param name
  * @return Class 注册对象的类型
  * @throws NoSuchBeanDefinitionException
  */
  public static Class getType(String name) throws NoSuchBeanDefinitionException {
    return applicationContext.getType(name);
  }
 
  /**
  * 如果给定的bean名字在bean定义中有别名,则返回这些别名   
  * @param name
  * @return
  * @throws NoSuchBeanDefinitionException
  */
  public static String[] getAliases(String name) throws NoSuchBeanDefinitionException {
    return applicationContext.getAliases(name);
  }
}</span>




action调用:

<span style="font-size:18px;"> 
public class UserAction extends BaseAction implements Action,ModelDriven{
    
    private Users user = new Users(); 
 //不用再加载springContext.xml文件,因为在web.xml中配置了,在程序中启动是就有了.    
    UserService userService = (UserService) SpringContextUtil.getBean("userService");
    
    public String execute() throws Exception {         
        return SUCCESS;
    }
 
  public Object getModel() {
        return user;
    }     
    
    public String getAllUser(){
        HttpServletRequest request = ServletActionContext.getRequest();         
        List ls=userService.LoadAllObject( Users.class );
        request.setAttribute("user",ls);     
        this.setUrl("/yonghu.jsp");
        return SUCCESS;
    }
}</span>



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