绝妙的+ jpa + maven = javax/xml/transform/Source 的加载器约束冲突

Question

如果我从 groovy 脚本创建 JPA EntityManager，我会收到以下错误：

java.lang.LinkageError: loader constraint violation: loader (instance of <bootloader>) previously initiated loading for a different type with name "javax/xml/transform/Source"
at javax.xml.validation.SchemaFactory.newSchema(SchemaFactory.java:594)
at org.hibernate.ejb.packaging.PersistenceXmlLoader.loadURL(PersistenceXmlLoader.java:89)
at org.hibernate.ejb.packaging.PersistenceXmlLoader.deploy(PersistenceXmlLoader.java:168)
at org.hibernate.ejb.Ejb3Configuration.configure(Ejb3Configuration.java:310)
at org.hibernate.ejb.HibernatePersistence.createEntityManagerFactory(HibernatePersistence.java:55)
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:48)
...

如果我从 java 类中的 main 方法创建 EntityManager，它将起作用。

我使用 mave，我的 pom 中的依赖项如下所示：

<dependencies>

    <dependency>
        <groupId>org.codehaus.groovy</groupId>
        <artifactId>groovy-all</artifactId>
        <version>1.7.6</version>
    </dependency>

    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.8.1</version>
        <scope>test</scope>
    </dependency>

    <dependency>
           <groupId>org.hibernate</groupId>
           <artifactId>hibernate-core</artifactId>
           <version>3.5.0-Final</version>
    </dependency>
    <dependency>
           <groupId>org.hibernate</groupId>
           <artifactId>hibernate-entitymanager</artifactId>
          <version>3.5.0-Final</version>
    </dependency>
    <dependency>
          <groupId>org.hibernate</groupId>
          <artifactId>hibernate-annotations</artifactId>
          <version>3.5.0-Final</version>
    </dependency>
    <dependency>
         <groupId>org.hibernate.javax.persistence</groupId>
         <artifactId>hibernate-jpa-2.0-api</artifactId>
         <version>1.0.0.Final</version>
    </dependency>

    <dependency>
        <groupId>postgresql</groupId>
        <artifactId>postgresql</artifactId>
        <version>8.3-606.jdbc3</version>
    </dependency>

    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-simple</artifactId>
        <version>1.5.8</version>
    </dependency>
    <dependency>
        <groupId>commons-logging</groupId>
        <artifactId>commons-logging</artifactId>
        <version>${commons-logging.version}</version>
        <scope>compile</scope>
    </dependency>

    <dependency>
        <groupId>log4j</groupId>
        <artifactId>log4j</artifactId>
        <version>${log4j.version}</version>
        <!--<scope>runtime</scope>-->
        <exclusions>
            <exclusion>
                <groupId>com.sun.jdmk</groupId>
                <artifactId>jmxtools</artifactId>
            </exclusion>
            <exclusion>
                <groupId>com.sun.jmx</groupId>
                <artifactId>jmxri</artifactId>
            </exclusion>
            <exclusion>
                <groupId>javax.mail</groupId>
                <artifactId>mail</artifactId>
            </exclusion>
            <exclusion>
                <groupId>javax.jms</groupId>
                <artifactId>jms</artifactId>
            </exclusion>
        </exclusions>
    </dependency>
    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-log4j12</artifactId>
        <version>1.6.1</version>
    </dependency>

</dependencies>

有人可以告诉我我犯了什么错误以及如何解决它吗？

梅德罗德

Answer 1

javax.xml.transform.Source 现在是 JDK 6 的一部分。似乎某些依赖项（可能是 Hibernate）对 xml-apis jar 文件（实际上也包含 java.xml.* 类）具有间接依赖项。您必须找到该依赖项并排除 xml-api。