一个java类实现了StatefulJob后，再继承就无法启动定时器

Question

//public class TimerByFourAccess extends XMLWriter implements StatefulJob {              //继承后定时器不执行
public class TimerByFourAccess implements StatefulJob {              //定时器可以执行
是这样的，我想在我的定时器里面继承XMLWriter这个类，但是一旦继承后，weblogic配置的定时器任务就会失效，我想知道这是为什么，<?xml version="1.0" encoding="UTF-8"?>
<quartz>
    <job>
        <job-detail>
            <name>SyncMoveCaseFile</name>
            <group>DEFAULT</group>
            <description>
                A job that prints out some basic information.
            </description>
            <job-class>
                com.sdf.workflosdfw.sdf.file.MoveCaseFile
            </job-class>
            <volatility>false</volatility>
            <durability>false</durability>
            <recover>false</recover>
        </job-detail>
        <trigger>
            <cron>
                <name>TSyncMoveCaseFilep</name>
                <group>DEFAULT</group>
                <job-name>SyncMoveCaseFile</job-name>
                <job-group>DEFAULT</job-group>
                <cron-expression>0/30 * * * * ?</cron-expression>
            </cron>
        </trigger>
    </job>
 
    
</quartz>

Answer 1

[ERROR]:2017-12-22 21:54:00  -- An error occured instantiating job to be executed. job= 'DEFAULT.TimerByFourAccess'
org.quartz.SchedulerException: Problem instantiating class 'com.agile.tool.timer.TimerByFourAccess' [See nested exception: java.lang.InstantiationException: com.agile.tool.timer.TimerByFourAccess]
        at org.quartz.simpl.SimpleJobFactory.newJob(SimpleJobFactory.java:52)
        at org.quartz.core.JobRunShell.initialize(JobRunShell.java:133)
        at org.quartz.core.QuartzSchedulerThread.run(QuartzSchedulerThread.java:353)
* Nested Exception (Underlying Cause) ---------------
java.lang.InstantiationException: com.asde.tool.timer.TimerByFourAccess
        at java.lang.Class.newInstance0(Class.java:342)
        at java.lang.Class.newInstance(Class.java:310)
        at org.quartz.simpl.SimpleJobFactory.newJob(SimpleJobFactory.java:50)
        at org.quartz.core.JobRunShell.initialize(JobRunShell.java:133)
        at org.quartz.core.QuartzSchedulerThread.run(QuartzSchedulerThread.java:353)