1 package com.demo.common.utils;
 2
 3 import org.apache.commons.lang3.Validate;
 4 import org.slf4j.Logger;
 5 import org.slf4j.LoggerFactory;
 6 import org.springframework.beans.BeansException;
 7 import org.springframework.beans.factory.DisposableBean;
 8 import org.springframework.context.ApplicationContext;
 9 import org.springframework.context.ApplicationContextAware;
10 import org.springframework.context.annotation.Lazy;
11 import org.springframework.stereotype.Service;
12
13 /**
14  * 以静态变量保存Spring ApplicationContext, 可在任何代码任何地方任何时候取出ApplicaitonContext.
15  * Created by Administrator on 2016/2/23.
16  */
17 @Service
18 @Lazy(false)
19 public class SpringContextHolder implements ApplicationContextAware ,DisposableBean {
20     private static ApplicationContext applicationContext = null;
21     private static Logger logger = LoggerFactory.getLogger(SpringContextHolder.class);
22
23     /**
24      * 去的存储在静态变量中的ApplicationContext
25      * @return
26      */
27     public static ApplicationContext getApplicationContext(){
28         assertContextInjected();
29         return applicationContext;
30     }
31
32     /**
33      * 从静态变量applicationContext中去的Bean，自动转型为所复制对象的类型
34      * @param name
35      * @param <T>
36      * @return
37      */
38     public static <T> T getBean(String name){
39         assertContextInjected();
40         return (T)applicationContext.getBean(name);
41     }
42
43     /**
44      * 从静态变量applicationContext中去的Bean，自动转型为所复制对象的类型
45      * @param requiredType
46      * @param <T>
47      * @return
48      */
49     public static <T> T getBean(Class<T> requiredType){
50         assertContextInjected();
51         return (T)applicationContext.getBean(requiredType);
52     }
53
54     /**
55      * 清楚SpringContextHolder中的ApplicationContext为Null
56      */
57     public static void clearHolder(){
58         if(logger.isDebugEnabled()){
59             logger.debug("清楚SpringContextHolder中的ApplicationContext:"+applicationContext);
60         }
61         applicationContext = null;
62     }
63
64
65     /**
66      * 检查ApplicationContext不为空
67      */
68     private static void assertContextInjected() {
69         Validate.validState(applicationContext!=null,"applicaitonContext属性未注入, 请在applicationContext.xml中定义SpringContextHolder.");
70     }
71
72     /**
73      * 实现ApplicationContextAware接口，注入Context到静态变量
74      * @param applicationContext
75      * @throws BeansException
76      */
77     @Override
78     public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
79         SpringContextHolder.applicationContext = applicationContext;
80     }
81
82     /**
83      * 实现DisposableBean接口，在Context关闭时清理静态变量
84      * @throws Exception
85      */
86     @Override
87     public void destroy() throws Exception {
88         SpringContextHolder.clearHolder();
89     }
90 }