[英]Null Pointer Exception when Calling repository in a class implementing Runnable
I have a project in which there is a use case where a user books a meeting lets suppose for 10am to 11 am with another user.我有一个项目,其中有一个用例,用户预订会议让我们假设上午 10 点到 11 点与另一个用户。 Now on the backend i want to check at 11 am if the meeting went well or not.现在在后端,我想在上午 11 点检查会议是否顺利。
For this i am using Scheduled Future and Runnable.为此,我使用 Scheduled Future 和 Runnable。 Whenever i book a meeting i create a scheduled future with the relevant meeting end time cron expression..which works fine but the problem is that i am not able to access repository or any of the services inside my run function which is necessary.每当我预订会议时,我都会使用相关的会议结束时间 cron 表达式创建一个预定的未来。它工作正常,但问题是我无法访问存储库或我运行的 function 中的任何服务,这是必要的。 i am getting a Null Pointer Exception我得到一个 Null 指针异常
Here is one of the meetingService Code which triggers using endpoint这是使用端点触发的会议服务代码之一
public String createMeetingSchedulerJobs(){
BookingDetails booking = repBooking.findAll().get(0);
//create completion check job
String[] dateParts = booking.getDateOfMeeting().split("/");
TaskDefinition taskDefinition = new TaskDefinition();
taskDefinition.setData(booking.getMeetingId());
taskDefinition.setActionType(TaskDefinitonType.MEETING_COMPLETION);
taskDefinition.setCronExpression(miscUtils.generateCronExpression(parseInt(dateParts[0]),parseInt(dateParts[1]),booking.getEndTimeHour(),booking.getEndTimeMinute(),0));
taskDefinitionBean.setTaskDefinition(taskDefinition);
taskDefinitionBean.setMiscUtils(miscUtils);
return taskSchedulerService.scheduleATask(taskDefinition);
}
the relevant schedulerService code相关的 schedulerService 代码
public String scheduleATask(TaskDefinition taskDefinition){
String jobId = UUID.randomUUID().toString();
taskDefinition.setId(jobId);
TaskDefinitionBean taskDefinitionBean = new TaskDefinitionBean();
taskDefinitionBean.setTaskDefinition(taskDefinition);
Runnable tasklet = taskDefinitionBean;
ScheduledFuture<?> scheduledTask = taskScheduler.schedule(tasklet, new CronTrigger(taskDefinition.getCronExpression(), TimeZone.getTimeZone(TimeZone.getDefault().getID())));
jobsMap.put(jobId, scheduledTask);
return jobsMap.toString();
}
Example Service示例服务
@Service
public class MiscellaneousUtils {
public String returnHello(){
return "Hello there ~";
}
}
TaskDefinitionBean.class任务定义Bean.class
@Configurable
@Service
public class TaskDefinitionBean implements Runnable{
private TaskDefinition taskDefinition;
private MiscellaneousUtils miscUtils;
private BeanFactory beanFactory;
@Override
public void run() {
miscUtils = beanFactory.getBean(MiscellaneousUtils.class);
}
public TaskDefinition getTaskDefinition(){
return taskDefinition;
}
public void setTaskDefinition(TaskDefinition taskDefinition){
this.taskDefinition=taskDefinition;
}
public void setMiscUtils(MiscellaneousUtils miscUtils){this.miscUtils=miscUtils;}
}
I have tried different types of dependency injection in TaskDefinitionBean.class but not successful.我在 TaskDefinitionBean.class 中尝试了不同类型的依赖注入,但没有成功。 I know there are many relevant and insightful questions which were similar but still couldn't use the approach.我知道有许多相关且有见地的问题是相似的,但仍然无法使用该方法。
The Error which i am getting is:我得到的错误是:
java.lang.NullPointerException: null
at fG.Service.TaskDefinitionBean.run(TaskDefinitionBean.java:38) ~[classes/:na]
at org.springframework.scheduling.support.DelegatingErrorHandlingRunnable.run(DelegatingErrorHandlingRunnable.java:54) ~[spring-context-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at org.springframework.scheduling.concurrent.ReschedulingRunnable.run(ReschedulingRunnable.java:93) [spring-context-5.2.5.RELEASE.jar:5.2.5.RELEASE]
at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:514) [na:na]
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) [na:na]
at java.base/java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:299) [na:na]
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167) [na:na]
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641) [na:na]
at java.base/java.lang.Thread.run(Thread.java:844) [na:na]
for dependency injection to work Your bean has to be created by spring, You create it manually依赖注入工作你的bean必须由spring创建,你手动创建它
TaskDefinitionBean taskDefinitionBean = new TaskDefinitionBean();
so beanFactory
is null
所以beanFactory
是null
You can Autowire beanFactory
in Service and pass it to TaskDefinitionBean
您可以在 Service 中自动装配beanFactory
并将其传递给TaskDefinitionBean
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