在Quartz的定时方法里引用@Autowired注入Bean，会报空指针错误
解决办法：
第一种方法：（推荐，简单，亲测可行）
使用@Resource(name="指定要注入的Bean")，代替@Autowired即可，指定了要注入的Bean名字，就能找到该Bean，就不会空指针了。
@Resource(name = "deviceStateProducerService")
private DeviceStateProducerService deviceStateProducerService;
示例代码：
看下面红色字体部分
代码
@Service("microDeviceStateService")
public class MicroDeviceStateServiceImpl implements MicroDeviceStateService {
@Resource(name = "deviceStateProducerService")
private DeviceStateProducerService deviceStateProducerService;
@Scheduled(cron="0/10 * * * * * ?")
@Lazy(false)
public void pingDeviceState() {
boolean isSuccess = PingUtils.ping("127.0.0.1", , );
MicroDeviceState microDeviceState = new MicroDeviceState();
if(!isSuccess) {
logger.debug("连接设备状态失败!");
microDeviceState.setDeviceState("");
}else {
microDeviceState.setDeviceState("");
}
microDeviceState.setDeviceFlag("");
microDeviceState.setIp("127.0.0.1");
DeviceStateBase deviceStateBase = new DeviceStateBase();
BeanUtils.copyProperties(microDeviceState, deviceStateBase);
deviceStateProducerService.deviceStateSender(deviceStateBase);
}
}
有的定时器不生效，在类上加注解@EnableScheduling（spring自带的定时任务功能）
配置文件
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:task="http://www.springframework.org/schema/task"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.1.xsd
http://www.springframework.org/schema/task
http://www.springframework.org/schema/task/spring-task-3.2.xsd"
default-lazy-init="true"> <task:scheduler id="scheduler" pool-size="" />
<task:executor id="executor" keep-alive="" pool-size="100-200"
queue-capacity="" rejection-policy="CALLER_RUNS" />
<task:annotation-driven executor="executor" scheduler="scheduler" />
<!-- 注解配置定时器 -->
<context:annotation-config />
<!-- spring扫描注解的配置（要扫描的包，即定时器所在包） -->
<context:component-scan base-package="com.zit.adapter.camera.CameraListener" /> </beans>
第二种方法：（也可行，不推荐）
使用Spring原生获取Bean的方法 取代 @Autowired注入，同时，不要与定时方法在同一个类
示例代码：
注解方式写了一个定时方法，方法里需要引用Dao层，插入数据库，
直接@Autowired会报空指针异常，做出如下红色字体改动
public class FTPUtil{
// @Autowired
// MicroCameraPassRecordDao microCameraPassRecordDao;
private static MicroCameraPassRecordDao microCameraPassRecordDao = null;
使用Spring获取注入bean
static {
microCameraPassRecordDao =
(MicroCameraPassRecordDao) SpringContextUtils.getApplicationContext().getBean("microCameraPassRecordDao");
}
/**
* 定时从FTP下载图片到本地，在这个方法里调用别的Dao层的方法
*/
@Scheduled(cron="0/20 * * * * * ?")
@Lazy(false)
public synchronized void service() {
FTPUtil ftpUtil = new FTPUtil();
boolean isConnect = ftpUtil.connectServer();
//从FTP下载到工程file下
boolean flag = ftpUtil.download(getFtpPath());
//引用注入Bean，插入数据库
MicroCameraPassRecord cameraRecord = new MicroCameraPassRecord();
cameraRecord.setCameraId(deviceID);
cameraRecord.setAddTime(System.currentTimeMillis());
microCameraPassRecordDao.insert(cameraRecord);
}
}
getBean（引用类名，开头字母小写）
SpringContextUtils
Spring获取Bean的工具类：
package com.zit.util; import java.util.Map; import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Service; @SuppressWarnings({ "rawtypes", "unchecked" })
@Service("springContextUtils")
public class SpringContextUtils implements ApplicationContextAware { private static ApplicationContext applicationContext; public void setApplicationContext(ApplicationContext arg0)
throws BeansException {
applicationContext = arg0;
} /**
* 获取applicationContext对象
* @return
*/
public static ApplicationContext getApplicationContext(){
return applicationContext;
} /**
* 根据bean的id来查找对象
* @param id
* @return
*/
public static Object getBeanById(String id){
return applicationContext.getBean(id);
} /**
* 根据bean的class来查找对象
* @param c
* @return
*/
public static Object getBeanByClass(Class c){
return applicationContext.getBean(c);
} /**
* 根据bean的class来查找所有的对象(包括子类)
* @param c
* @return
*/
public static Map getBeansByClass(Class c){
return applicationContext.getBeansOfType(c);
} }