Question

我正在尝试创建一个将从Net-bean本地运行的简单应用程序，但每次我尝试执行数据库操作时都会出错。

[EL Info]：2015-10-25 09：48：21.192 - ServerSession（26304643） - EclipseLink，版本：Eclipse Persistence Services - 2.3.2.v20111125-r10461 [EL Severe]：2015-10-25 09：48：23.42 - ServerSession（26304643） - 例外[EclipseLink-4002]（Eclipse Persistence Services - 2.3.2.v20111125-r10461）：org.eclipse.persistence.exceptions .DatabaseException 线程“AWT-EventQueue-0”中的异常javax.persistence.PersistenceException：Exception [EclipseLink-4002]（Eclipse Persistence Services - 2.3.2.v20111125-r10461）：org.eclipse.persistence.exceptions.DatabaseException 内部异常：java.sql.SQLNonTransientConnectionException：java.net.ConnectException：在端口1527上连接到服务器localhost时出错，并显示消息Connection refused：connect。错误代码：40000 内部异常：java.sql.SQLNonTransientConnectionException：java.net.ConnectException：在端口1527上连接到服务器localhost时出错，并显示消息Connection refused：connect。

我只是在这种情况下执行一个简单的查询

   private void btnSelectLastActionPerformed(java.awt.event.ActionEvent evt) {                                              
    String last = JOptionPane.showInputDialog(null, "Please enter the student's last name");

    Query q = GeoBeeAppPUEntityManager.createQuery("SELCT t FROM tblStudentsList WHERE t.lastname = ?1 ORDER BY t.firstname");
    q.setParameter(1,last );

    List<Tblstudents> LastList = q.getResultList();

    tblstudentsList2.clear();
    tblstudentsList2.addAll(LastList);

这就是持久性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="GeoBeeAppPU" transaction-type="RESOURCE_LOCAL">
<provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
<class>org.me.mybackgroundapp.Tblstudents</class>
<class>org.me.mybackgroundapp.Tblstudentscores</class>
<class>org.me.mybackgroundapp.Tblquizquestions</class>
<class>org.me.mybackgroundapp.Tblteachers</class>
<properties>
  <property name="javax.persistence.jdbc.url" value="jdbc:derby://localhost:1527/GeoBee_DB"/>
  <property name="javax.persistence.jdbc.password" value=""/>
  <property name="javax.persistence.jdbc.driver" value="org.apache.derby.jdbc.ClientDriver"/>
  <property name="javax.persistence.jdbc.user" value=""/>
</properties>

修复错误代码40000. SQLNonTransientConnectionException

0 个答案: