获取spring bean的utils

<span style="font-size:10px;">package com.record.util;

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

import java.util.Map;

/**
 * 以静态变量保存Spring ApplicationContext.
 */
@SuppressWarnings("unchecked")
public class SpringContextUtil implements ApplicationContextAware {

    private static ApplicationContext applicationContext;

    public static ApplicationContext getApplicationContext() {
        if (applicationContext == null)
            throw new IllegalStateException("applicaitonContext未注入,请在applicationContext.xml中定义SpringContextUtil");
        return applicationContext;
    }

    /**
     * ApplicationContextAware接口的context注入函数.
     */
    public void setApplicationContext(ApplicationContext context) throws BeansException {
        applicationContext = context;
    }

    public static <T> T getBean(String name) throws BeansException {
        return (T) applicationContext.getBean(name);
    }

    public static <T> T getBean(Class<T> cls) {
        return getBean(cls, applicationContext);
    }

    public static <T> T getBean(Class<T> cls, ApplicationContext ctx) {
        Map<String, T> map = ctx.getBeansOfType(cls);
        if (map == null || map.size() == 0) {
            return null;
        }
        if (map.size() > 1) {
            new Exception("bean is not unique.").printStackTrace();
        }
        return map.values().iterator().next();
    }
}</span>

<span style="font-size:10px;">//对于无法获取spring容器的class 如servlet等 可以方便的获取spring容器中的bean, 配合 servlet3.0注解（如@WebServlet(urlPatterns = "/mobile/report/billExcel", asyncSupported = true)）等 对原有项目可以做到完全不侵入，爽歪歪啊</span>