Google app engine AppEngine和x2B的工作Maven3配置；DataNucleus+；JPA 2

我正试图通过Maven创建GAE项目，我面临着持久性库配置的问题。我尝试包含不同的依赖项并指定不同的作用域，但总是会出现以下错误：

java.lang.NoClassDefFoundError: org/datanucleus/ObjectManagerFactoryImpl

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在此处检查GAE依赖项

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您可能使用了一些不兼容的版本。

嗯，最终我找到了解决我的问题的方法：

    <!-- Persistence Dependencies -->
    <dependency>
        <groupId>com.google.appengine.orm</groupId>
        <artifactId>datanucleus-appengine</artifactId>
        <version>2.1.2</version>
    </dependency>
    <dependency>
        <groupId>javax.jdo</groupId>
        <artifactId>jdo-api</artifactId>
        <version>3.0.1</version>
    </dependency>
    <dependency>
        <groupId>org.apache.geronimo.specs</groupId>
        <artifactId>geronimo-jpa_2.0_spec</artifactId>
        <version>1.1</version>
    </dependency>
    <dependency>
        <groupId>org.datanucleus</groupId>
        <artifactId>datanucleus-core</artifactId>
        <version>[3.1.1, 3.1.99]</version>
    </dependency>
    <dependency>
        <groupId>org.datanucleus</groupId>
        <artifactId>datanucleus-api-jpa</artifactId>
        <version>[3.1.1, 3.1.99]</version>
    </dependency>
    <dependency>
        <groupId>org.datanucleus</groupId>
        <artifactId>datanucleus-jpa-query</artifactId>
        <version>3.0.2</version>
    </dependency>

com.google.appengine.orm
datanucleus appengine
2.1.2
javax.jdo
jdoapi
3.0.1
org.apache.geronimo.specs
geronimo-jpa_2.0_规范
1.1
org.datanucleus
数据核核心
[3.1.1, 3.1.99]
org.datanucleus
datanucleus api jpa
[3.1.1, 3.1.99]
org.datanucleus
datanucleus jpa查询
3.0.2

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我希望它能帮助有同样问题的人。

您使用的是JPA2，所以请从该列表中删除“javax.persistence”（JPA1）（您使用下面的geronimo规范JPA2 jar）

java.lang.NoClassDefFoundError: org/datanucleus/ClassLoaderResolver

Invocation of init method failed; nested exception is javax.persistence.PersistenceException: No persistence providers available for "transactions-optional" after trying the following discovered implementations: org.datanucleus.api.jpa.PersistenceProviderImpl

    <!-- Persistence Dependencies -->
    <dependency>
        <groupId>com.google.appengine.orm</groupId>
        <artifactId>datanucleus-appengine</artifactId>
        <version>2.1.2</version>
    </dependency>
    <dependency>
        <groupId>javax.jdo</groupId>
        <artifactId>jdo-api</artifactId>
        <version>3.0.1</version>
    </dependency>
    <dependency>
        <groupId>org.apache.geronimo.specs</groupId>
        <artifactId>geronimo-jpa_2.0_spec</artifactId>
        <version>1.1</version>
    </dependency>
    <dependency>
        <groupId>org.datanucleus</groupId>
        <artifactId>datanucleus-core</artifactId>
        <version>[3.1.1, 3.1.99]</version>
    </dependency>
    <dependency>
        <groupId>org.datanucleus</groupId>
        <artifactId>datanucleus-api-jpa</artifactId>
        <version>[3.1.1, 3.1.99]</version>
    </dependency>
    <dependency>
        <groupId>org.datanucleus</groupId>
        <artifactId>datanucleus-jpa-query</artifactId>
        <version>3.0.2</version>
    </dependency>