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• 2018-12-02 00:42發(fā)布了問答

  數(shù)控加工ZX設(shè)備未來有幾個發(fā)展趨勢？

  　

  304人看過

• 2018-06-28 14:44發(fā)布了問答

  CNC手板加工那家精度高？

  　

  466人看過

• 2018-06-20 23:23發(fā)布了問答

  3D打印手板的價格怎么算

  　

  479人看過

• 2018-01-24 13:50發(fā)布了問答

  世界數(shù)控機床系統(tǒng)有哪些？

  　

  504人看過

• 2017-09-29 02:32發(fā)布了問答

  如何查看xenserver連接的HBA卡WWN號

  　

  499人看過

• 2012-07-09 14:59發(fā)布了問答

  請教現(xiàn)場總線PROFIBUS DP/FMS隔離中繼器的作用

  　

  564人看過

• 2012-03-22 18:27發(fā)布了問答

  吉林省工業(yè)相機-機器視覺等哪里做的比較好？希望大家推薦下

  　

  449人看過

• 2012-01-06 08:08發(fā)布了問答

  大家好！請問酸辣土豆絲怎么做？步驟 可以詳細點更好！謝了！

  　

  469人看過

• 2010-09-21 12:12發(fā)布了問答

  Java GUI鏈接sqlserver的問題

  run: Exception in thread "AWT-EventQueue-0" javax.persistence.PersistenceException: No Persistence provider for EntityManager named localhost:1433;DatabaseName=OSPU: Provider named oracle.toplink.essentials.PersistenceProvider threw unexpe... run: Exception in thread "AWT-EventQueue-0" javax.persistence.PersistenceException: No Persistence provider for EntityManager named localhost:1433;DatabaseName=OSPU: Provider named oracle.toplink.essentials.PersistenceProvider threw unexpected exception at create EntityManagerFactory: oracle.toplink.essentials.exceptions.PersistenceUnitLoadingException Local Exception Stack: ) at java.awt.EventDispatchThread.run(EventDispatchThread.java:121) Caused by: javax.persistence.PersistenceException: Exception [TOPLINK-28018] (Oracle TopLink Essentials - 2.0.1 (Build b09d-fcs (12/06/2007))): oracle.toplink.essentials.exceptions.EntityManagerSetupException Exception Description: predeploy for PersistenceUnit [localhost:1433;DatabaseName=OSPU] failed. Internal Exception: Exception [TOPLINK-30007] (Oracle TopLink Essentials - 2.0.1 (Build b09d-fcs (12/06/2007))): oracle.toplink.essentials.exceptions.PersistenceUnitLoadingException Exception Description: An exception was thrown while loading class: Base.Car to check whether it implements @Entity， @Embeddable， or @MappedSuperclass. Internal Exception: java.lang.ClassNotFoundException: Base.Car 我的sqlserver已經(jīng)在Netbean成功連接了，可以在NetBeans查看到了數(shù)據(jù)庫的信息。。 可是還是顯示Exception Description: predeploy for PersistenceUnit [localhost:1433;DatabaseName=OSPU] failed. Z主要的是Caused by: java.lang.ClassNotFoundException: Base.Car ，這個Base.car文件已經(jīng)被我刪除了，怎么還顯示不能生成類啊。。跪求高手解答 展開

  478人看過

• 2009-04-02 22:40發(fā)布了問答

  cnc和nc代碼有何區(qū)別？

  數(shù)控加工中的常常用到cnc和nc代碼， 我想知道兩者有什么區(qū)別？ 謝謝！

  941人看過