package com.ruixin.common.utils;
import org.apache.commons.lang3.Validate;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.annotation.Lazy;
import org.springframework.stereotype.Service;
/**
* 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.
*/
@Service
@Lazy(false)
public class SpringContextHolder implements ApplicationContextAware, DisposableBean {
private static ApplicationContext applicationContext = null;
private static Logger logger = LoggerFactory.getLogger(SpringContextHolder.class);
/**
* 取得存储在静态变量中的ApplicationContext.
*/
public static ApplicationContext getApplicationContext() {
assertContextInjected();
return applicationContext;
}
/**
* 从静态变量applicationContext中取得Bean, 自动转型为所赋值对象的类型.
*/
@SuppressWarnings("unchecked")
public static <T> T getBean(String name) {
assertContextInjected();
return (T) applicationContext.getBean(name);
}
/**
* 从静态变量applicationContext中取得Bean, 自动转型为所赋值对象的类型.
*/
public static <T> T getBean(Class<T> requiredType) {
assertContextInjected();
return applicationContext.getBean(requiredType);
}
/**
* 清除SpringContextHolder中的ApplicationContext为Null.
*/
public static void clearHolder() {
if (logger.isDebugEnabled()){
logger.debug("清除SpringContextHolder中的ApplicationContext:" + applicationContext);
}
applicationContext = null;
}
/**
* 实现ApplicationContextAware接口, 注入Context到静态变量中.
*/
@Override
public void setApplicationContext(ApplicationContext applicationContext) {
logger.debug("注入ApplicationContext到SpringContextHolder:{}", applicationContext);
if (SpringContextHolder.applicationContext != null) {
logger.info("SpringContextHolder中的ApplicationContext被覆盖, 原有ApplicationContext为:" + SpringContextHolder.applicationContext);
}
SpringContextHolder.applicationContext = applicationContext; // NOSONAR
}
/**
* 实现DisposableBean接口, 在Context关闭时清理静态变量.
*/
@Override
public void destroy() throws Exception {
SpringContextHolder.clearHolder();
}
/**
* 检查ApplicationContext不为空.
*/
private static void assertContextInjected() {
Validate.validState(applicationContext != null, "applicaitonContext属性未注入, 请在applicationContext.xml中定义SpringContextHolder.");
}
}