几种取得spring里注册Bean的方法 转载

几种获得spring里注册Bean的方法 转载


  /**
  * 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);
  }
}




action调用：
package com.anymusic.oa.webwork;

import java.util.List;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;

import com.anymusic.oa.commons.service.ServiceLocator;
import com.anymusic.oa.hibernate.pojo.Role;
import com.anymusic.oa.hibernate.pojo.Users;
import com.anymusic.oa.spring.IUserService;
import com.opensymphony.webwork.ServletActionContext;
import com.opensymphony.xwork.Action;
import com.opensymphony.xwork.ActionContext;
import com.opensymphony.xwork.ModelDriven;

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;
    }
}




四.通过servlet 或listener设置spring的ApplicationContext,以便后来引用.
注意分别extends  ContextLoaderListener和ContextLoaderServlet .然后就可用SpringContext来getBean.
覆盖原来在web.xml中配置的listener或servlet.

public class SpringContext  {
  private static ApplicationContext applicationContext;     //Spring应用上下文环境


  */
  public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
    SpringContextUtil.applicationContext = applicationContext;
  }

  /**
  * @return ApplicationContext
  */
  public static ApplicationContext getApplicationContext() {
    return applicationContext;
  }


  */
  public static Object getBean(String name) throws BeansException {
    return applicationContext.getBean(name);
  }

}

public class SpringContextLoaderListener extends ContextLoaderListener{  //
public void contextInitialized(ServletContextEvent event) { 
  super.contextInitialized(event);
  SpringContext.setApplicationContext(
    WebApplicationContextUtils.getWebApplicationContext(event.getServletContext())
    );
}
}

public class SpringContextLoaderServlet extends ContextLoaderServlet {
private ContextLoader contextLoader;
    public void init() throws ServletException {
        this.contextLoader = createContextLoader();
        SpringContext.setApplicationContext(this.contextLoader.initWebApplicationContext(getServletContext()));
    }
}