Spring学习笔记(三) SpringContextUtil获取bean

1.通过下面的方式得到bean测试中遇到资源耗尽的严重bug

ApplicationContext context = new ClassPathXmlApplicationContext(new String[]{"applicationContext.xml","spring-xxx.xml"});  
BeanFactory factory = (BeanFactory)context;  
A a = (A) factory.getBean("a"); 

2.Spring配置文件中加<bean class="com.*.util.SpringContextUtil" lazy-init="false" /> 
可以利用该Util获取配置文件的bean或者注解的bean

 

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

import java.util.Map;

/**
 * @ProjectName: []
 * @Author: []
 * @CreateDate: []
 * @Version: [v1.0]
 */
public class SpringContextUtil implements ApplicationContextAware {
    private static ApplicationContext applicationContext;

    /**
     * 实现ApplicationContextAware接口的回调方法，设置上下文环境
     * @param applicationContext
     * @throws org.springframework.beans.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 org.springframework.beans.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 org.springframework.beans.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 org.springframework.beans.factory.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 org.springframework.beans.factory.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 org.springframework.beans.factory.NoSuchBeanDefinitionException
     */
    public static String[] getAliases(String name) throws NoSuchBeanDefinitionException {
        return applicationContext.getAliases(name);
    }
    /**
     * 根据全路径包名返回bean
     * @param name
     * @return
     * @throws org.springframework.beans.factory.NoSuchBeanDefinitionException
     */
    public static Map getBeanByType(String name){
        try {
            return applicationContext.getBeansOfType(Class.forName(name));
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
            return null;
        }
    }

}