如下問題，其實解決方法非常簡單：
用shiro自帶的ExecutorServiceSessionValidationScheduler 可以正常代替QuartzSessionValidationScheduler

<!-- 會話驗證排程器 -->
<bean id="sessionValidationScheduler"
    class="org.apache.shiro.session.mgt.ExecutorServiceSessionValidationScheduler">
        <property name="interval" value
 
="${shiro.sessionTimeout}" /> <!-- 30分鐘 -->
        <property name="sessionManager" ref="sessionManager" />
    </bean>

以下為網上對應展現的解決方法，經過試驗，會造成FGC頻繁的情況：

緣由：在使用shiro時，如果Quartz 為Quartz 2的版本，則丟擲異常Java.lang.InstantiationError: org.quartz.SimpleTrigger。原因是預設的shiro-quartz1.2.3中的實現是針對quartz1.6版本的實現（詳細原始碼請檢視org.apache.shiro.session.mgt.quartz.QuartzSessionValidationScheduler），在quartz2.2.1中，SimppleTrigger為介面，所以無法例項化。如果使用Quartz 2，則需要自定義Quartz 2的實現

package org.apache.shiro.session.mgt.quartz;  

/** 
 * Created by koko on 2016/7/20. 
 */  
import org.apache.shiro.session.mgt.ValidatingSessionManager;  
import org.quartz.Job;  
import org.quartz.JobDataMap;  
import org.quartz.JobExecutionContext;  
import org.quartz.JobExecutionException;  
import
 
 org.slf4j.Logger;  
import org.slf4j.LoggerFactory;  

/** 
 * 基於Quartz 2.* 版本的實現 
 * 
 */  
public class QuartzSessionValidationJob2 implements Job {  

    /** 
     * Key used to store the session manager in the job data map for this job. 
     */  
    public static final String SESSION_MANAGER_KEY = "sessionManager";  

    /*-------------------------------------------- 
    |    I N S T A N C E   V A R I A B L E S    | 
    ============================================*/  
    private static final Logger log = LoggerFactory.getLogger(QuartzSessionValidationJob2.class);  

    /*-------------------------------------------- 
    |         C O N S T R U C T O R S           | 
    ============================================*/  

    /*-------------------------------------------- 
    |  A C C E S S O R S / M O D I F I E R S    | 
    ============================================*/  

    /*-------------------------------------------- 
    |               M E T H O D S               | 
    ============================================*/  

    /** 
     * Called when the job is executed by quartz. This method delegates to the <tt>validateSessions()</tt> method on the 
     * associated session manager. 
     * 
     * @param context 
     *            the Quartz job execution context for this execution. 
     */  
    public void execute(JobExecutionContext context) throws JobExecutionException {  

        JobDataMap jobDataMap = context.getMergedJobDataMap();  
        ValidatingSessionManager sessionManager = (ValidatingSessionManager) jobDataMap.get(SESSION_MANAGER_KEY);  

        if (log.isDebugEnabled()) {  
            log.debug("Executing session validation Quartz job...");  
        }  

        sessionManager.validateSessions();  

        if (log.isDebugEnabled()) {  
            log.debug("Session validation Quartz job complete.");  
        }  
    }  

}  

第二個類 spring注入的也是這個類

package org.apache.shiro.session.mgt.quartz;  

/** 
 * Created by koko on 2016/7/20. 
 */  
import org.apache.shiro.session.mgt.DefaultSessionManager;  
import org.apache.shiro.session.mgt.SessionValidationScheduler;  
import org.apache.shiro.session.mgt.ValidatingSessionManager;  
import org.quartz.JobBuilder;  
import org.quartz.JobDetail;  
import org.quartz.Scheduler;  
import org.quartz.SchedulerException;  
import org.quartz.SimpleScheduleBuilder;  
import org.quartz.SimpleTrigger;  
import org.quartz.TriggerBuilder;  
import org.quartz.TriggerKey;  
import org.quartz.impl.StdSchedulerFactory;  
import org.slf4j.Logger;  
import org.slf4j.LoggerFactory;  

/** 
 * 基於Quartz 2.* 版本的實現 
 */  
public class QuartzSessionValidationScheduler2 implements SessionValidationScheduler {  

    public static final long DEFAULT_SESSION_VALIDATION_INTERVAL = DefaultSessionManager.DEFAULT_SESSION_VALIDATION_INTERVAL;  
    private static final String JOB_NAME = "SessionValidationJob";  
    private static final Logger log = LoggerFactory.getLogger(QuartzSessionValidationScheduler2.class);  
    private static final String SESSION_MANAGER_KEY = QuartzSessionValidationJob2.SESSION_MANAGER_KEY;  
    private Scheduler scheduler;  
    private boolean schedulerImplicitlyCreated = false;  

    private boolean enabled = false;  
    private ValidatingSessionManager sessionManager;  
    private long sessionValidationInterval = DEFAULT_SESSION_VALIDATION_INTERVAL;  

    public QuartzSessionValidationScheduler2() {  
    }  

    public QuartzSessionValidationScheduler2(ValidatingSessionManager sessionManager) {  
        this.sessionManager = sessionManager;  
    }  

    protected Scheduler getScheduler() throws SchedulerException {  
        if (this.scheduler == null) {  
            this.scheduler = StdSchedulerFactory.getDefaultScheduler();  
            this.schedulerImplicitlyCreated = true;  
        }  
        return this.scheduler;  
    }  

    public void setScheduler(Scheduler scheduler) {  
        this.scheduler = scheduler;  
    }  

    public void setSessionManager(ValidatingSessionManager sessionManager) {  
        this.sessionManager = sessionManager;  
    }  

    public boolean isEnabled() {  
        return this.enabled;  
    }  

    public void setSessionValidationInterval(long sessionValidationInterval) {  
        this.sessionValidationInterval = sessionValidationInterval;  
    }  

    public void enableSessionValidation() {  
        if (log.isDebugEnabled()) {  
            log.debug("Scheduling session validation job using Quartz with session validation interval of ["  
                    + this.sessionValidationInterval + "]ms...");  
        }  

        try {  
            SimpleTrigger trigger = TriggerBuilder.newTrigger().startNow().withIdentity(JOB_NAME, Scheduler.DEFAULT_GROUP)  
                    .withSchedule(SimpleScheduleBuilder.simpleSchedule().withIntervalInMilliseconds(sessionValidationInterval))  
                    .build();//<span style="color:#ff0000;">Quartz 2中的實現</span>  

            JobDetail detail = JobBuilder.newJob(QuartzSessionValidationJob2.class)  
                    .withIdentity(JOB_NAME, Scheduler.DEFAULT_GROUP).build();  
            detail.getJobDataMap().put(SESSION_MANAGER_KEY, this.sessionManager);  
            Scheduler scheduler = getScheduler();  

            scheduler.scheduleJob(detail, trigger);  
            if (this.schedulerImplicitlyCreated) {  
                scheduler.start();  
                if (log.isDebugEnabled()) {  
                    log.debug("Successfully started implicitly created Quartz Scheduler instance.");  
                }  
            }  
            this.enabled = true;  

            if (log.isDebugEnabled())  
                log.debug("Session validation job successfully scheduled with Quartz.");  
        } catch (SchedulerException e) {  
            if (log.isErrorEnabled())  
                log.error("Error starting the Quartz session validation job.  Session validation may not occur.", e);  
        }  
    }  

    public void disableSessionValidation() {  
        if (log.isDebugEnabled()) {  
            log.debug("Stopping Quartz session validation job...");  
        }  
        Scheduler scheduler;  
        try {  
            scheduler = getScheduler();  
            if (scheduler == null) {  
                if (log.isWarnEnabled()) {  
                    log.warn("getScheduler() method returned a null Quartz scheduler, which is unexpected.  Please check your configuration and/or implementation.  Returning quietly since there is no validation job to remove (scheduler does not exist).");  
                }  

                return;  
            }  
        } catch (SchedulerException e) {  
            if (log.isWarnEnabled()) {  
                log.warn("Unable to acquire Quartz Scheduler.  Ignoring and returning (already stopped?)", e);  
            }  
            return;  
        }  
        try {  
            scheduler.unscheduleJob(new TriggerKey("SessionValidationJob", "DEFAULT"));  
            if (log.isDebugEnabled())  
                log.debug("Quartz session validation job stopped successfully.");  
        } catch (SchedulerException e) {  
            if (log.isDebugEnabled()) {  
                log.debug("Could not cleanly remove SessionValidationJob from Quartz scheduler.  Ignoring and stopping.", e);  
            }  

        }  

        this.enabled = false;  

        if (this.schedulerImplicitlyCreated)  
            try {  
                scheduler.shutdown();  
            } catch (SchedulerException e) {  
                if (log.isWarnEnabled())  
                    log.warn("Unable to cleanly shutdown implicitly created Quartz Scheduler instance.", e);  
            } finally {  
                setScheduler(null);  
                this.schedulerImplicitlyCreated = false;  
            }  
    }  

}  

最後在spring的配置檔案中配置shiro的quartz配置

<bean id="sessionValidationScheduler"    class="org.apache.shiro.session.mgt.quartz.QuartzSessionValidationScheduler2">  
        <property name="sessionValidationInterval" value="1800000"/>  
        <property name="sessionManager" ref="sessionManager"/>  
    </bean>