如何在JPA EntityManager查询上设置超时期限 [英] How to set the timeout period on a JPA EntityManager query

问题描述

我目前从EntityManager查询中收到连接超时错误.可以为这些设置超时吗?

I'm currently getting connection timeout errors from my EntityManager queries. Is it possible to set a timeout for these?

persistence.xml

persistence.xml

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.0" xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd">
  <persistence-unit name="CallPU" transaction-type="RESOURCE_LOCAL">
    <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
    <class>call.structure.Task</class>
    <class>call.structure.Installation</class>
    <class>call.structure.Contents</class>
    <class>call.structure.Recipient</class>
    <class>call.structure.CallTask</class>
    <class>call.structure.SmsTask</class>
    <class>call.structure.EmailTask</class>
    <class>call.security.User</class>
    <class>call.structure.content.Content</class>
    <class>call.structure.content.RecordContent</class>
    <class>call.structure.content.WaitContent</class>
    <class>call.structure.content.TextContent</class>
    <class>call.structure.content.VariableContent</class>
    <class>call.structure.content.SoundContent</class>
    <class>call.structure.content.SubjectContent</class>
    <class>call.structure.content.FileContent</class>
    <class>call.structure.Bounce</class>
    <properties>
      <property name="javax.persistence.jdbc.url" value="jdbc:oracle:thin:@127.0.0.1:1521:TEST"/>
      <property name="javax.persistence.jdbc.password" value="userpassword"/>
      <property name="javax.persistence.jdbc.driver" value="oracle.jdbc.OracleDriver"/>
      <property name="javax.persistence.jdbc.user" value="username"/>
    </properties>
   </persistence-unit>
</persistence>

代码在我的线程的运行功能中超时:

Code times out in the run function of my thread:

private class TaskDB extends Thread {

    private final long WAITING_TIME = 20000L;

    @Override
    public void run() {

        Set<SmsTask> remove = SMSManager.this.getRemoveTask();
        Set<SmsTask> normal = SMSManager.this.getNormalTask();

        try {
            while(true){
                EntityManager em = DB.getEM();  //Calls EntityManagerFactory.createEntityManager()
                em.getTransaction().begin();

                Set<SmsTask> normalClone = new HashSet<SmsTask>(normal);
                // Abort task in futur.
                List<SmsTask> taskToRemove = new ArrayList<SmsTask>();
                if (!remove.isEmpty()) {

                    String queryString = "SELECT t FROM SmsTask t WHERE t.id IN :remove ";
                    if (!normalClone.isEmpty())
                        queryString += "AND t.id NOT IN :normal ";

                    Query query = em.createQuery(queryString);
                    query.setParameter("remove", Utils.taskToIdList(remove));
                    if (!normalClone.isEmpty())
                        query.setParameter("normal", Utils.taskToIdList(normalClone));

                    taskToRemove = (List<SmsTask>) query.getResultList();
                    for (SmsTask task : taskToRemove) {
                        removedTask.add(task);
                        remove.remove(task);
                    }
                }

                String queryString = "SELECT t FROM SmsTask t WHERE (t.scheduleTime IS NULL OR t.scheduleTime < :dateNow) AND t.status = co.dium.call.structure.Task.StatusTask.NOT_START ";
                if (!taskToRemove.isEmpty())
                    queryString += "AND t.id NOT IN :toRemove ";

                Query query = em.createQuery(queryString);
                query.setParameter("dateNow", Utils.obtainUniversalTime());
                if (!taskToRemove.isEmpty())
                    query.setParameter("toRemove", Utils.taskToIdList(taskToRemove));
                List<SmsTask> taskResults = (List<SmsTask>) query.getResultList();

                em.getTransaction().commit();

                for (SmsTask task : taskResults) 
                    addTask(task);

                SMSManager.TaskRemove.sleep(WAITING_TIME);
            }
        } catch (InterruptedException ex) {
            Logger.getLogger(SMSManager.class.getName()).log(Level.SEVERE, null, ex);
        }

        System.out.println("Thread interrompu !");
        Thread.currentThread().interrupt();
    }
}

我得到的超时错误:

org.clipse.persistence.exceptions.DatabaseException
Internal Exception: java.sql.SQLRecoverableException: I/O error: Socket read timed out
Error Code: 17002
Call: [....sql query...]
[...]
at org.eclipse.persistence.internal.EJBQueryImpl.getResultList(EJBQueryImpl.java:742)
at call.manager.sms.SMSManager$TaskDB.run(SMSManager.java:367)
Caused by: java.sql.SQLRecoverableException: I/O Error: Scoket read timed out
[...]

推荐答案

是的，还有 javax.persistence.query.timeout .根据JPA 2.0规范，对此查询提示的支持是可选的:

Yes, there javax.persistence.query.timeout. According JPA 2.0 specification support for this query hint is optional:

便携式应用程序不应依赖此提示.取决于 持久性提供程序和数据库正在使用中，提示可能会或可能不会 观察到.

Portable applications should not rely on this hint. Depending on the persistence provider and database in use, the hint may or may not be observed.

可以将所有查询的默认值(以毫秒为单位)设置为persistence.xml:

Default value (in milliseconds) can be set to persistence.xml for all queries:

<property name="javax.persistence.query.timeout" value="1000"/>

通过Persistence创建EntityManagerFactory时，也可以赋予相同的属性.

Same property can be also given when creating EntityManagerFactory via Persistence.createEntityManagerFactory.

每个查询也可以覆盖/设置它:

It can also be overridden/set per query:

query.setHint("javax.persistence.query.timeout", 2000);

可以通过属性提示在NamedQuery中.

Same functionality can be obtained via attribute hints in NamedQuery.

这篇关于如何在JPA EntityManager查询上设置超时期限的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！