使用Future和@Aync时休眠两个打开的会话

Question

我正在尝试在我的应用程序中使用多线程来完成一些需要几分钟才能完成的任务。 我的想法是，我有n个对象，因此我希望对这些对象进行并行处理，而又不让用户（Web应用程序）等待它们完成（因为这需要几分钟）。同样在其他情况下（当对象数量为一个时），我想等到该过程完成后，用户才能看到结果。

但是我遇到了一些问题。

所以我的代码是： RunSomeTaskServiceImpl：

-XX:+UseGCLogFileRotation -XX:NumberOfGCLogFiles=5 -XX:GCLogFileSize=2M"

RunSomeTaskService：

public class RunSomeTaskServiceImpl extends CommonService implements RunSomeTaskService{

    @Async
    @Override
        public Future<Response> doTasks(Student student) {
              Response response = new Response();
              //do Tasks
              return new AsyncResult<Response>(response);
           }
    }

StudentServiceImpl：

public interface RunSomeTaskService{
    public Future<Response> doTasks(Student student);
}

因此，当一个以上的学生时，我会收到错误消息：

@Autowired
RunSomeTaskService runSomeTaskService;

@Override
Transactional
public Response save(StudentBO[] students) throws Exception {
    ...
    for (StudentBO student : students) {
        ....
        Future<Response> response = runSomeTaskService.doTasks(student);
        if(students.size() == 1){
           return response.get();
        }
    }
....
}

只有一个时：

12:17:44.040 [DEMO-4] DEBUG o.h.r.t.b.j.i.JdbcResourceLocalTransactionCoordinatorImpl - JDBC transaction marked for rollback-only (exception provided for stack trace)
java.lang.Exception: exception just for purpose of providing stack trace
        at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl$TransactionDriverControlImpl.markRollbackOnly(JdbcResourceLocalTransactionCoordinatorImpl.java:265) [hibernate-core-5.0.6.Final.jar:5.0.6.Final]
        at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl.beforeCompletionCallback(JdbcResourceLocalTransactionCoordinatorImpl.java:156) [hibernate-core-5.0.6.Final.jar:5.0.6.Final]
        at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl.access$100(JdbcResourceLocalTransactionCoordinatorImpl.java:38) [hibernate-core-5.0.6.Final.jar:5.0.6.Final]
        at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl$TransactionDriverControlImpl.commit(JdbcResourceLocalTransactionCoordinatorImpl.java:231) [hibernate-core-5.0.6.Final.jar:5.0.6.Final]
        at org.hibernate.engine.transaction.internal.TransactionImpl.commit(TransactionImpl.java:65) [hibernate-core-5.0.6.Final.jar:5.0.6.Final]
        at org.springframework.orm.hibernate5.HibernateTransactionManager.doCommit(HibernateTransactionManager.java:581) [spring-orm-4.2.4.RELEASE.jar:4.2.4.RELEASE]
        at org.springframework.transaction.support.AbstractPlatformTransactionManager.processCommit(AbstractPlatformTransactionManager.java:761) [spring-tx-4.2.4.RELEASE.jar:4.2.4.RELEASE]
        at org.springframework.transaction.support.AbstractPlatformTransactionManager.commit(AbstractPlatformTransactionManager.java:730) [spring-tx-4.2.4.RELEASE.jar:4.2.4.RELEASE]
        at org.springframework.transaction.interceptor.TransactionAspectSupport.commitTransactionAfterReturning(TransactionAspectSupport.java:485) [spring-tx-4.2.4.RELEASE.jar:4.2.4.RELEASE]
        at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:291) [spring-tx-4.2.4.RELEASE.jar:4.2.4.RELEASE]
        at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96) [spring-tx-4.2.4.RELEASE.jar:4.2.4.RELEASE]
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) [spring-aop-4.2.4.RELEASE.jar:4.2.4.RELEASE]
        at org.springframework.aop.interceptor.AsyncExecutionInterceptor$1.call(AsyncExecutionInterceptor.java:108) [spring-aop-4.2.4.RELEASE.jar:4.2.4.RELEASE]
        at org.springframework.aop.interceptor.AsyncExecutionAspectSupport$CompletableFutureDelegate$1.get(AsyncExecutionAspectSupport.java:237) [spring-aop-4.2.4.RELEASE.jar:4.2.4.RELEASE]
        at java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1590) [na:1.8.0_171]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_171]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_171]
        at java.lang.Thread.run(Thread.java:748) [na:1.8.0_171]
12:17:44.043 [DEMO-4] DEBUG o.s.o.h.HibernateTransactionManager - Initiating transaction rollback after commit exception
org.hibernate.AssertionFailure: null id in com.app.model.FieldValue entry (don't flush the Session after an exception occurs)

学生模型

org.hibernate.HibernateException: Illegal attempt to associate a collection with two open sessions. Collection : <unknown>
Collection contents: [[]]
        at org.hibernate.collection.internal.AbstractPersistentCollection.setCurrentSession(AbstractPersistentCollection.java:627)
        at org.hibernate.event.internal.OnUpdateVisitor.processCollection(OnUpdateVisitor.java:46)
        at org.hibernate.event.internal.AbstractVisitor.processValue(AbstractVisitor.java:104)
        at org.hibernate.event.internal.AbstractVisitor.processValue(AbstractVisitor.java:65)
        at org.hibernate.event.internal.AbstractVisitor.processEntityPropertyValues(AbstractVisitor.java:59)
        at org.hibernate.event.internal.AbstractVisitor.process(AbstractVisitor.java:126)
        at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.performUpdate(DefaultSaveOrUpdateEventListener.java:293)
        at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.entityIsDetached(DefaultSaveOrUpdateEventListener.java:227)
        at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.performSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:92)
        at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:73)
        at org.hibernate.internal.SessionImpl.fireSaveOrUpdate(SessionImpl.java:648)
        at org.hibernate.internal.SessionImpl.saveOrUpdate(SessionImpl.java:640)
        at org.hibernate.internal.SessionImpl.saveOrUpdate(SessionImpl.java:635)
        at com.app.dao.CommonDaoImpl.addOrUpdate(CommonDaoImpl.java:28)
        at com.app.services.ExtractDataServiceImpl.doExtraction(ExtractDataServiceImpl.java:361)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:302)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:190)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
        at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99)
        at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:281)
        at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
        at org.springframework.aop.interceptor.AsyncExecutionInterceptor$1.call(AsyncExecutionInterceptor.java:108)
        at org.springframework.aop.interceptor.AsyncExecutionAspectSupport$CompletableFutureDelegate$1.get(AsyncExecutionAspectSupport.java:237)
        at java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1590)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
        at java.lang.Thread.run(Thread.java:748)

spring-config.xml文件

package com.app.model;
// Generated 18-jul-2018 15:27:32 by Hibernate Tools 5.2.10.Final

import java.util.Date;
import java.util.HashSet;
import java.util.Set;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import static javax.persistence.GenerationType.IDENTITY;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.OneToMany;
import javax.persistence.Table;
import javax.persistence.Temporal;
import javax.persistence.TemporalType;
import javax.persistence.UniqueConstraint;

/**
 * Student generated by hbm2java
 */
@Entity
@Table(name = "student", catalog = "school_db", uniqueConstraints = @UniqueConstraint(columnNames = "code"))
public class Student implements java.io.Serializable {

    private Integer id;
    private String name;
    private Grade grade;
    private Set<Subject> subjects = new HashSet<Subject>(0);

    public Student() {
    }


    @Id
    @GeneratedValue(strategy = IDENTITY)

    @Column(name = "id", unique = true, nullable = false)
    public Integer getId() {
        return this.id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "grade")
    public Grade getGrade() {
        return this.grade;
    }

    public void setGrade(Grade grade) {
        this.grade = grade;
    }

    @OneToMany(fetch = FetchType.LAZY, mappedBy = "student")
    public Set<Subject> getSubjects() {
        return this.subjects;
    }

    public void setSubjects(Set<Subject> subjects) {
        this.subjects = subjects;
    }

    @OneToMany(fetch = FetchType.LAZY, mappedBy = "student")
    public Set<Subject> getSubjects() {
        return this.subjects;
    }

}

那么您能帮我避免这个问题吗？