在类路径中找不到任何META-INF/persistence.xml文件，但我已经添加了它

Question

我试图添加JPA到我的项目，但总是得到这些错误：

keycloak_1   | 17:28:43,494 INFO  [org.hibernate.jpa.boot.internal.PersistenceXmlParser] (default task-2) HHH000318: Could not find any META-INF/persistence.xml file in the classpath
keycloak_1   | 17:28:43,495 ERROR [org.keycloak.services.error.KeycloakErrorHandler] (default task-2) Uncaught server error: javax.persistence.PersistenceException: No Persistence provider for EntityManager named SQL

但是当我尝试初始化我的实体管理器时：

HashMap<String, String> properties = new HashMap<>();
properties.put("javax.persistence.jdbc.driver", configMap.getFirst(CONFIG_KEY_JDBC_URL));
properties.put("javax.persistence.jdbc.url", configMap.getFirst(CONFIG_KEY_JDBC_URL));
properties.put("javax.persistence.jdbc.user", configMap.getFirst(CONFIG_KEY_DB_USERNAME));
properties.put("javax.persistence.jdbc.password", configMap.getFirst(CONFIG_KEY_DB_PASSWORD));

EntityManagerFactory entityManagerFactory = Persistence.createEntityManagerFactory(
        "SQL",
        properties
);

EntityManager entityManager = entityManagerFactory.createEntityManager();

我收到了这些错误，但我不明白这是怎么可能的，然后我清楚地将该文件添加到我的数据库中。罐子

坚持不懈xml内容是：

<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_2.xsd"
             version="2.2">
    <persistence-unit name="SQL" transaction-type="RESOURCE_LOCAL">
        <properties>
            <property name="javax.persistence.jdbc.driver" value=""/>
            <property name="javax.persistence.jdbc.url" value=""/>
            <property name="javax.persistence.jdbc.user" value=""/>
            <property name="javax.persistence.jdbc.password" value=""/>
        </properties>
    </persistence-unit>
</persistence>

这里可以看到项目和编译的jar的结构（持久性内容更改为2.2版本，如前所述）：

我做错了什么？

更新：即使查找命令返回文件存在于正确的目录：

➜  sql-sync-spi find . -type f -name "persistence.xml"
./build/resources/main/META-INF/persistence.xml
./src/main/resources/META-INF/persistence.xml

更多更新：我试图从另一个项目复制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="user-storage-jpa-example">
        <jta-data-source>java:jboss/datasources/ExampleDS</jta-data-source>

        <class>org.keycloak.quickstart.storage.user.UserEntity</class>

        <properties>
            <property name="hibernate.hbm2ddl.auto" value="update" />
            <property name="hibernate.show_sql" value="false" />
        </properties>
    </persistence-unit>
</persistence>

在服务启动时，我收到了致命错误：

07:03:02,188 ERROR [org.jboss.as.controller.management-operation] (Controller Boot Thread) WFLYCTL0013: Operation ("deploy") failed - address: ([("deployment" => "sql-sync-spi-1.0-SNAPSHOT.jar")]) - failure description: {
    "WFLYCTL0412: Required services that are not installed:" => ["jboss.naming.context.java.jboss.datasources.ExampleDS1"],
    "WFLYCTL0180: Services with missing/unavailable dependencies" => [
        "jboss.persistenceunit.\"sql-sync-spi-1.0-SNAPSHOT.jar#sql\".__FIRST_PHASE__ is missing [jboss.naming.context.java.jboss.datasources.ExampleDS]",
        "jboss.persistenceunit.\"sql-sync-spi-1.0-SNAPSHOT.jar#sql\" is missing [jboss.naming.context.java.jboss.datasources.ExampleDS1]"
    ]
}

因此，至少在项目的一部分中肯定会看到持久性。xml文件，并尝试读取它。然后，我将xml更改回我的设置，并且再次在启动时没有错误，但在entity manager初始化尝试时，类路径中再次没有文件。

Answer 1

这更多的是一个评论，而不是一个答案，因为评论部分没有足够的空间，我还没有证实这一点。

首先，我要在您的密钥斗篷服务器上定义一个新的数据源。请参见：关系数据库设置。

build的依赖项部分。gradle应该看起来有点像：

dependencies {
    compileOnly 'org.keycloak:keycloak-server-spi'
    compileOnly 'org.keycloak:keycloak-common'
    implementation 'org.apache.commons:commons-lang3:3.12.0'
    compileOnly 'org.hibernate.javax.persistance:hibernate-jpa-2.1-api:1.0.0.Final'
    compileOnly 'org.jboss.spec.javax.ejb:jboss-ejb-api_3.2_spec:1.0.0.Final'

    compileOnly platform('org.wildfly.bom:wildfly-javaee8:14.0.1.Final')
    compileOnly platform('org.keycloak.bom:keycloak-spi-bom:15.0.1')
}

你的持久性。xml应该会改变，因为我们在KeyClope上定义了一个数据源：

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.1"
    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">
    <persistence-unit name="yourDataSource">
        <jta-data-source>your_DS_name</jta-data-source>
        <!-- List your entities here. For example: -->
        <class>com.rmndbrvn.sqlsyncspi.UserEntity</class>
    </persistence-unit>
</persistence>

然后，您可以在代码中获得EntityManager的实例，如下所示：

@PersistenceContext(unitName = "yourDataSource")
EntityManager em;