同一个tomcat实例下多个应用之间相互调用的实现

项目开发中遇到同一个tomcat下的多个应用之间会相互调用的问题,分享一下实现方法。

背景:

tomcat有project1，project2两个应用,在project2中需要调用project1中bean里的方法。

预置条件:

tomcat server.xml文件中两个应用的Context 分别增加 crossContext="true"属性。

project1代码实现:

servletContextListener,将spring里的bean写入到servlet容器中,方便project2中引用

import javax.servlet.ServletContext;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;

import org.springframework.context.ApplicationContext;
import org.springframework.web.context.WebApplicationContext;

public class ServiceExposer implements ServletContextListener {
	public void contextInitialized(ServletContextEvent sce) {
		//获取ServletContext对象
		ServletContext context = sce.getServletContext();
		//获取应用Context对象
		ApplicationContext appContext = (ApplicationContext)context.getAttribute(WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE);
		//将spring里的bean对象注入到web容器,方便project2中引用
		exposeSearchHotWordsService(context, appContext);
	}
	
	private void exposeSearchHotWordsService(ServletContext context, ApplicationContext appContext){
		SearchHotWordsService searchHotWordsService = appContext.getBean(SearchHotWordsService.class);
		context.setAttribute("searchHotWordsService", searchHotWordsService);
	}
	
	public void contextDestroyed(ServletContextEvent sce) {
	}

}

project2代码实现：

增加HttpSessionListener实现类,获取project1中的bean

import javax.servlet.ServletContext;
import javax.servlet.ServletContextEvent;
import javax.servlet.http.HttpSession;
import javax.servlet.http.HttpSessionEvent;
import javax.servlet.http.HttpSessionListener;

import org.apache.log4j.Logger;

public class ServiceListener implements HttpSessionListener {
	private final static Logger logger = Logger.getLogger(ServiceListener.class); 
	public void contextDestroyed(ServletContextEvent sce) {
		
	}
	@Override
	public void sessionCreated(HttpSessionEvent se) {
		if(!StoreService.getInstance().isSearchHotWordsServiceReady()){
			//获取project1中的bean实例
			Object service = getBeanFromStoreContext(se, "searchHotWordsService");
			StoreService.getInstance().setSearchHotWordsService(service);
		}
	}
	
	private Object getBeanFromStoreContext(HttpSessionEvent se,String beanName){
		ServletContext storeCtx = se.getSession().getServletContext().getContext("Project1");
		if(storeCtx != null){
			Object service = storeCtx.getAttribute(beanName);
			return service;
		}
		return null;
	}
}

调用project1 bean里的方法

package com.test;

import java.lang.reflect.Method;
import java.util.LinkedList;
import java.util.List;

import javax.servlet.ServletContext;

import org.apache.log4j.Logger;
import org.springframework.beans.BeanUtils;

import com.yulong.coolcloud.coolstore.zsPush.ZeusisPushResponse;

public class StoreService {
	private static Logger logger = Logger.getLogger(StoreService.class);
	
	//单例
	private static StoreService singleService = new StoreService();
	
	//project1中的bean
	private Object searchHotWordsService;

	public boolean isSearchHotWordsServiceReady(){
		return this.searchHotWordsService != null;
	}
	
	public void updateWeightFromStatic(){
		if(searchHotWordsService!=null){
			Method insertLog;
			try{
				//利用反射调用project1里searchHotWordsService bean的updateWeightFromStatic方法
				insertLog = searchHotWordsService.getClass().getMethod("updateWeightFromStatic");
				insertLog.invoke(searchHotWordsService);
			}catch(Exception e){
				throw new RuntimeException(e);
			}
		}
	}
	
	public static StoreService getInstance(){
		return singleService;
	}

	public void setSearchHotWordsService(Object searchHotWordsService) {
		this.searchHotWordsService = searchHotWordsService;
	}
}

测试是否调用成功:

public class Test {

	public static void main(String[] args) {
		StoreService.getInstance().updateWeightFromStatic();
	}

}