无法使用 DeleteDbFiles.execute 使用 Java 删除我的 h2 数据库文件

Question

我想用 DeleteDbFiles.execute("./data", "mydb", false) 删除 h2 数据库文件，但出现以下错误：org.h2.message.DbException: Cannot delete file "dir/data/mydb.mv.db". 和Caused by: org.h2.jdbc.JdbcSQLNonTransientException: Cannot delete file "dir/data/mydb.mv.db".我试图关闭 EntityManager em (em.close()) 和 EntityManagerFactory emf (emf.close()) 然后删除文件但仍然出现相同的错误。我试图从 mainForm 中删除 @persistencecontext 但仍然出现相同的错误。这是我的代码：主要课程：import...public class Main {JalaliCalendar jalaliCalendar = new JalaliCalendar();EntityManagerFactory emf = Persistence.createEntityManagerFactory("NewPersistenceUnit");List<LoginEntity> list = new ArrayList<>();public Main(){    getData();    interance();}public void interance(){    if (!list.isEmpty()){        LoginForm loginForm = new LoginForm(list);        loginForm.setTitle("پنجره ورود");        loginForm.setContentPane(loginForm.mainpane);        loginForm.pack();        loginForm.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);        loginForm.setLocationRelativeTo(null);        loginForm.setVisible(true);    }else {        Wellcome wellcome = new Wellcome();        wellcome.setTitle("خوش آمدید");        wellcome.setContentPane(wellcome.mainpane);        wellcome.pack();        wellcome.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);        wellcome.setLocationRelativeTo(null);        wellcome.setVisible(true);    }}public void getData(){    EntityManager em = emf.createEntityManager();    em.getTransaction().begin();    Query query = em.createQuery("from LoginEntity ");    list = query.getResultList();    em.getTransaction().commit();    em.close();}public void getDiff(){    JalaliCalendar j1 = new JalaliCalendar();    j1.setYear(1398);    j1.setMonth(3);    j1.setDay(5);    JalaliCalendar j2 = new JalaliCalendar();    j2.setYear(1398);    j2.setMonth(2);    j2.setDay(5);}

Answer 1

只需像下面这样更改我的 persistence.xml 内容，然后在删除文件之前关闭 EntityManagerFactory。

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>

<persistence xmlns="http://xmlns.jcp.org/xml/ns/persistence"

     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

     xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd"

     version="2.1">

<persistence-unit name="NewPersistenceUnit">

<provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>

<class>model.MycardsEntity</class>

<class>model.PeymentsEntity</class>

<class>model.WorkersEntity</class>

<class>model.YourcardsEntity</class>

<class>model.LoginEntity</class>

<properties>

    <property name="hibernate.connection.url" value="jdbc:h2:file:./data/mydata;DB_CLOSE_ON_EXIT=FALSE;FILE_LOCK=NO"/>

    <property name="hibernate.connection.driver_class" value="org.h2.Driver"/>

    <property name="hibernate.connection.username" value=""/>

    <property name="hibernate.connection.password" value=""/>

    <property name="hibernate.archive.autodetection" value="class"/>

    <property name="hibernate.show_sql" value="true"/>

    <property name="hibernate.format_sql" value="true"/>

    <property name="hbm2ddl.auto" value="update"/>

</properties>

</persistence-unit>

现在可以使用以下方式删除文件：

DeleteDbFiles.execute("./data", "mydb", false);