注入或獲取spring上下文的幾種方式

方式一:經過ApplicationContextAware 注入

package com.girltest.web.controller.common;

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

/***
 * 暴露spring context給非spring容器的對象使用
 *
 * @author pengsong
 */
@Configuration
public class SpringContext implements ApplicationContextAware {

    protected static ApplicationContext context;

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        context = applicationContext;
    }

    public static ApplicationContext getContext() {
        return context;
    }

    public static <T> T getBean(Class<T> beanClass) {
        return context.getBean(beanClass);
    }

    public static <T> T getBean(String name, Class<T> beanClass) {
        return context.getBean(name, beanClass);
    }
}

注意:必定要給類SpringContext 增長註解@org.springframework.context.annotation.Configuration or @ Service

方式二:經過WebApplicationContextUtils

獲取 HTTP request:

/***
 * 獲取http請求上下文
 * @return
 */
public static HttpServletRequest getRequest() {
    ServletRequestAttributes servletRequestAttributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
    if (null == servletRequestAttributes) {
        return null;
    }
    HttpServletRequest request = servletRequestAttributes.getRequest();
    return request;
}

/***
 * 獲取spring MVC請求上下文
 * @return
 */
public static SpringMVCContext getSpringMVCContext() {
    HttpServletRequest request = getRequest();
    HttpServletResponse response = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getResponse();
    SpringMVCContext springMVCContext = new SpringMVCContext();
    WebApplicationContext webApp = WebApplicationContextUtils.getWebApplicationContext(request.getSession().getServletContext());
    springMVCContext.setRequest(request);
    springMVCContext.setResponse(response);
    springMVCContext.setWebApp(webApp);
    return springMVCContext;
}
/***
 *
 * @param request
 * @param beanName : 例如 userDao ,adminDao
 * @return
 */
public static Object getBean(HttpServletRequest request, String beanName) {
    WebApplicationContext webApp = WebApplicationContextUtils.getWebApplicationContext(request.getSession().getServletContext());
    return webApp.getBean(beanName);
}

注意:若是上述方法不是在web 請求鏈條中執行,則沒法獲取request.