在做项目的时候,往往有很多情况是会在非Spring的容器下需要用到Spring管理的组件的,比如说:定时器,servlet,拦截器等等,在这种情况下通常都想使用数据库操作的时候都会感觉到乏力,因为在这种环境下,你要调用相关的Dao层的东西,往往想用依赖注入来实现,卻每每跑出来的就都是空指针异常.
举个例子说明:
public class TaskManager implements ServletContextListener { // 每天的毫秒数 public static final long DAY = 86400000; // 定时器 private Timer timer; // @Autowired // private GamesetTask gamesetTask; /** * 在Web应用结束时停止任务 */ public void contextDestroyed(ServletContextEvent sce) { timer.cancel();// 定时器销毁 } /** * 在Web应用启动时初始化任务 */ public void contextInitialized(ServletContextEvent sce) { SpringBeanAutowiringSupport.processInjectionBasedOnCurrentContext(this); // 定义定时器 Calendar c = Calendar.getInstance(); c.add(Calendar.DATE, 1); c.set(c.get(Calendar.YEAR), c.get(Calendar.MONTH), c.get(Calendar.DAY_OF_MONTH), 0, 0, 0); timer = new Timer(true); GamesetTask gamesetTask = new GamesetTask();// 定时执行的内容 // timer.schedule(locationTask, c.getTime(), DAY); //定时器在每日凌晨0点执行 timer.schedule(gamesetTask, 5000, 4 * 60 * 1000); // 启动后5秒执行,后每隔1小时在执行 // timer.schedule(gamesetTask, 5000, 5 * 1000); } }
具体的任务如下:
package com.smartsoft.task; import java.util.Date; import java.util.TimerTask; import net.sf.json.JSONObject; import org.apache.commons.httpclient.HttpClient; import org.apache.commons.httpclient.methods.PostMethod; import org.apache.commons.httpclient.methods.RequestEntity; import org.apache.commons.httpclient.methods.StringRequestEntity; import org.apache.commons.lang.math.RandomUtils; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Component; import org.springframework.web.context.support.SpringBeanAutowiringSupport; import com.smartsoft.common.Constants; import com.smartsoft.dao.GamesetDao; import com.smartsoft.service.GamesetService; @Component("gamesetTask") public class GamesetTask extends TimerTask { private static boolean isRunning = false; private static int t = 1 ; private static int i = 1 ; @Autowired private GamesetService gamesetService; @Autowired private GamesetDao gamesetDao; public GamesetTask() { SpringBeanAutowiringSupport.processInjectionBasedOnCurrentContext(this); } @Override public void run() { if (!isRunning) { isRunning = true; System.out.println("-----ganmeset add-------"); addGemest(); isRunning = false; } else { System.out.println("-----ganmeset error-------"); } } private void addGemest() { if(t==1){ System.out.println("---------request:newGameSet-------------"); sendHttpRequest("{\"api_key\":\"test"+i+"\",\"table_no\":\"A001\",\"computer_name\":\"computer001\",\"game_set\":\""+i+"\",\"shoe_of_the_day\":\""+i+"\",\"game_time\":\""+new Date()+"\",\"status\":\"1\"}", "http://127.0.0.1:8080/bdb/gameset!newGameSet", Constants.HTTP_CONTENT_TYPE_APPLICATION_JSON); }else{ int ttt = RandomUtils.nextInt(3); String res = ""; if(ttt==0){ res = "T"; }else if(ttt==1){ res = "B"; }else{ res = "P"; } System.out.println("---------request:submitGameResult-------------"); sendHttpRequest("{\"api_key\":\"test"+i+"\",\"table_no\":\"A001\",\"computer_name\":\"computer001\",\"game_set\":\""+i+"\",\"shoe_of_the_day\":\""+i+"\",\"game_time\":\""+new Date()+"\",\"game_no\":\""+i+"\",\"active_game_no\":\""+i+"\",\"win\":\""+res+"\",\"win_type\":\"\",\"banker_pair\":\""+RandomUtils.nextInt(2)+"\",\"player_pair\":\""+RandomUtils.nextInt(2)+"\",\"status\":\"1\"}", "http://127.0.0.1:8080/bdb/gameset!submitGameResult", Constants.HTTP_CONTENT_TYPE_APPLICATION_JSON); i++; System.out.println("---------request:newGameSet-------------"); sendHttpRequest("{\"api_key\":\"test"+i+"\",\"table_no\":\"A001\",\"computer_name\":\"computer001\",\"game_set\":\""+i+"\",\"shoe_of_the_day\":\""+i+"\",\"game_time\":\""+new Date()+"\",\"status\":\"1\"}", "http://127.0.0.1:8080/bdb/gameset!newGameSet", Constants.HTTP_CONTENT_TYPE_APPLICATION_JSON); } t++; } /** * httpClient * @param reqStr * @param urlConfig * @param contentType * @return */ private int sendHttpRequest(String reqStr,String urlConfig,String contentType) { try { PostMethod postMethod = new PostMethod(urlConfig); RequestEntity requestEntity = new StringRequestEntity(reqStr,contentType,Constants.CONTENT_ENCODING_UTF8); postMethod.setRequestEntity(requestEntity); HttpClient httpClient = new HttpClient(); httpClient.executeMethod(postMethod); JsonResultModel jsonResult=(JsonResultModel)JSONObject.toBean(JSONObject.fromObject(postMethod.getResponseBodyAsString()),JsonResultModel.class); int httpStatus = Integer.parseInt(jsonResult.getStatus()); return httpStatus; } catch (Exception e) { return 500; } } public static void main(String[] args) { //随机数0或1 for (int i = 0; i < 50; i++) { System.out.println(RandomUtils.nextInt(2)); } } }
@Autowired private GamesetService gamesetService; @Autowired private GamesetDao gamesetDao;
办法很多
网上有人公布怎么获取ioc上下文的,这个也很好明白,但是代码量就比较多,如果有兴趣了解,可以度娘关键字"Web项目中获取SpringBean"
这里我的写法是引入
SpringBeanAutowiringSupport.processInjectionBasedOnCurrentContext(this);这是Spring的自动装备,有了他前面的注解就不会空指针了,而且代码也美观,整洁
如果有什么不懂,大家可以留言或者问下度娘咯,反正我也是问度娘多
版权声明:本文为博主原创文章,未经博主允许不得转载。
原文地址:http://blog.csdn.net/qq183293/article/details/47420823