@Autowired注入Bean为Null，通过spring工具类获取bean

第一种

import org.springframework.beans.BeansException;

import org.springframework.beans.factory.NoSuchBeanDefinitionException;

import org.springframework.context.ApplicationContext;

import org.springframework.context.ApplicationContextAware;

import org.springframework.stereotype.Component;

 
@Component

public class SpringUtils implements ApplicationContextAware {

    private static ApplicationContext applicationContext = null;

    public SpringUtils() {
    }

    public void setApplicationContext(ApplicationContext arg0) throws BeansException {
        if (applicationContext == null) {
            applicationContext = arg0;
        }
    }

    public static ApplicationContext getApplicationContext() {
        return applicationContext;
    }

    public static void setAppCtx(ApplicationContext webAppCtx) {
        if (webAppCtx != null) {
            applicationContext = webAppCtx;
        }
    }
    /**
     * 拿到ApplicationContext对象实例后就可以手动获取Bean的注入实例对象
     */
    public static <T> T getBean(Class<T> clazz) {
        return getApplicationContext().getBean(clazz);
    }

    public static <T> T getBean(String name, Class<T> clazz) throws ClassNotFoundException {
        return getApplicationContext().getBean(name, clazz);
    }

    public static final Object getBean(String beanName) {
        return getApplicationContext().getBean(beanName);
    }

 

    public static final Object getBean(String beanName, String className) throws ClassNotFoundException {
        Class<?> clz = Class.forName(className);
        return getApplicationContext().getBean(beanName, clz.getClass());
    }

}