为什么 Maven 要使用 javax.persistence 而不是替代的 hibernate 版本答案

【问题标题】：Why does Maven want to use javax.persistence instead of the alternative hibernate version为什么 Maven 要使用 javax.persistence 而不是替代的 hibernate 版本
【发布时间】：2020-09-26 11:42:55
【问题描述】：

我有一些代码使用：

import javax.persistence.*;

我在 pom.xml 中有以下依赖项：

<dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>5.4.15.Final</version>
        </dependency>
        <dependency>
            <groupId>org.hibernate.javax.persistence</groupId>
            <artifactId>hibernate-jpa-2.1-api</artifactId>
            <version>1.0.2.Final</version>
        </dependency>

我可以使用“mvn compile”进行编译，但是当我尝试“mvn package”时，出现以下错误：

[WARNING] Used undeclared dependencies found:
[WARNING]    javax.persistence:javax.persistence-api:jar:2.2:compile
[WARNING] Unused declared dependencies found:
[WARNING]    org.hibernate.javax.persistence:hibernate-jpa-2.1-api:jar:1.0.2.Final:compile
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------

我从 hibernate-jpa-2.1-api 检查了 jar，它确实包含 javax.persistence.* 类。

那么，为什么 Maven 不接受这是要使用的 jar 并坚持要使用 javax.persistence-api 呢？

如果我尝试切换到 javax.persistence:javax.persistence-api:jar:2.2 而不是 hibernate 的，我会从“mvn package”中得到很多错误，如下所示：

[WARNING] Found duplicate (but equal) classes in [jakarta.xml.bind:jakarta.xml.bind-api:2.3.3, javax.xml.bind:jaxb-api:2.3.1]:
[WARNING]   javax.xml.bind.DatatypeConverterInterface
[WARNING]   javax.xml.bind.Element
[WARNING]   javax.xml.bind.JAXBContextFactory
[WARNING]   javax.xml.bind.Marshaller
[WARNING]   javax.xml.bind.NotIdentifiableEvent
[WARNING]   javax.xml.bind.ParseConversionEvent
[WARNING]   javax.xml.bind.PrintConversionEvent
[WARNING]   javax.xml.bind.Unmarshaller
[WARNING]   javax.xml.bind.UnmarshallerHandler
[WARNING]   javax.xml.bind.ValidationEvent
[WARNING]   javax.xml.bind.ValidationEventHandler
[WARNING]   javax.xml.bind.ValidationEventLocator
[WARNING]   javax.xml.bind.Validator
[WARNING]   javax.xml.bind.annotation.DomHandler
[WARNING]   javax.xml.bind.annotation.XmlAccessorOrder
[WARNING]   javax.xml.bind.annotation.XmlAccessorType
[WARNING]   javax.xml.bind.annotation.XmlAnyAttribute
[WARNING]   javax.xml.bind.annotation.XmlAnyElement
[WARNING]   javax.xml.bind.annotation.XmlAttachmentRef
[WARNING]   javax.xml.bind.annotation.XmlAttribute
[WARNING]   javax.xml.bind.annotation.XmlElement
[WARNING]   javax.xml.bind.annotation.XmlElementDecl
[WARNING]   javax.xml.bind.annotation.XmlElementRef
[WARNING]   javax.xml.bind.annotation.XmlElementRefs
[WARNING]   javax.xml.bind.annotation.XmlElementWrapper
<...lots more lines like this>

有什么想法吗？

【问题讨论】：

标签： java hibernate maven jpa

【解决方案1】：

这真的很简单：org.hibernate:hibernate-core:5.4.15.Final 依赖于来自javax.persistence:javax.persistence-api:2.2 的javax.persistence.* 类（这是在其自己的 POM 中声明的依赖项），因此，通过包含 hibernate-core，您可以获得额外的传递依赖项javax.persistence-api拉进来。这就是为什么您会收到“发现已使用未声明的依赖项”警告的原因。

出于同样的原因，不使用org.hibernate.javax.persistence:hibernate-jpa-2.1-api:1.0.2.Final。请注意，Maven没有知道hibernate-jpa-2.1-api 和javax.persistence-api 应该可以互换。

如果出于某种奇怪的原因，您想强制使用 hibernate-jpa-2.1-api，则需要明确排除 javax.persistence-api 作为传递依赖项，如下所示：

<dependency>
    <groupId>org.hibernate</groupId>
    <artifactId>hibernate-core</artifactId>
    <version>5.4.15.Final</version>
    <exclusions>
        <exclusion>
            <groupId>javax.persistence</groupId>
            <artifactId>javax.persistence-api</artifactId>
        </exclusion>
    </exclusions>
</dependency>

【讨论】：

【解决方案2】：

1.0.2.Final - 这个声明说：允许任何版本，但更喜欢 1.0.2.FINAL。如果要指定 exact 版本，请将其声明为 <version>[1.0.2.Final]</version>

通常在解决传递依赖（或冲突，在这种情况下不是这种情况）时，Maven 会选择最近的依赖。在这种情况下，javax.persistence:javax.persistence-api:jar:2.2:compile 更接近于org.hibernate:hibernate-core:jar:5.4.15.Final:compile。

mvn dependency:tree
 [INFO] Scanning for projects...
 [INFO] 
 [INFO] -----------------------< org.example:so-answers >-----------------------
 [INFO] Building so-answers 1.0-SNAPSHOT
 [INFO] --------------------------------[ jar ]---------------------------------
 [INFO] 
 [INFO] --- maven-dependency-plugin:2.8:tree (default-cli) @ so-answers ---
 [INFO] org.example:so-answers:jar:1.0-SNAPSHOT
 [INFO] +- org.hibernate:hibernate-core:jar:5.4.15.Final:compile
 [INFO] |  +- org.jboss.logging:jboss-logging:jar:3.3.2.Final:compile
 [INFO] |  +- javax.persistence:javax.persistence-api:jar:2.2:compile
 [INFO] |  +- org.javassist:javassist:jar:3.24.0-GA:compile
 [INFO] |  +- net.bytebuddy:byte-buddy:jar:1.10.10:compile
 [INFO] |  +- antlr:antlr:jar:2.7.7:compile
 [INFO] |  +- org.jboss.spec.javax.transaction:jboss-transaction-api_1.2_spec:jar:1.1.1.Final:compile
 [INFO] |  +- org.jboss:jandex:jar:2.1.3.Final:compile
 [INFO] |  +- com.fasterxml:classmate:jar:1.5.1:compile
 [INFO] |  +- javax.activation:javax.activation-api:jar:1.2.0:compile
 [INFO] |  +- org.dom4j:dom4j:jar:2.1.3:compile
 [INFO] |  +- org.hibernate.common:hibernate-commons-annotations:jar:5.1.0.Final:compile
 [INFO] |  +- javax.xml.bind:jaxb-api:jar:2.3.1:compile
 [INFO] |  \- org.glassfish.jaxb:jaxb-runtime:jar:2.3.1:compile
 [INFO] |     +- org.glassfish.jaxb:txw2:jar:2.3.1:compile
 [INFO] |     +- com.sun.istack:istack-commons-runtime:jar:3.0.7:compile
 [INFO] |     +- org.jvnet.staxex:stax-ex:jar:1.8:compile
 [INFO] |     \- com.sun.xml.fastinfoset:FastInfoset:jar:1.2.15:compile
 [INFO] \- org.hibernate.javax.persistence:hibernate-jpa-2.1-api:jar:1.0.2.Final:compile
 [INFO] ------------------------------------------------------------------------
 [INFO] BUILD SUCCESS
 [INFO] ------------------------------------------------------------------------
 [INFO] Total time: 0.790 s
 [INFO] Finished at: 2020-09-26T10:02:50-04:00
 [INFO] ------------------------------------------------------------------------

让我们添加排除以影响分辨率。

<dependencies>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>5.4.15.Final</version>
            <exclusions>
                <exclusion>
                    <groupId>javax.persistence</groupId>
                    <artifactId>javax.persistence-api</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.hibernate.javax.persistence</groupId>
            <artifactId>hibernate-jpa-2.1-api</artifactId>
            <version>1.0.2.Final</version>
        </dependency>
    </dependencies>

然后再次检查依赖树

  mvn dependency:tree
    [INFO] Scanning for projects...
    [INFO] 
    [INFO] -----------------------< org.example:so-answers >-----------------------
    [INFO] Building so-answers 1.0-SNAPSHOT
    [INFO] --------------------------------[ jar ]---------------------------------
    [INFO] 
    [INFO] --- maven-dependency-plugin:2.8:tree (default-cli) @ so-answers ---
    [INFO] org.example:so-answers:jar:1.0-SNAPSHOT
    [INFO] +- org.hibernate:hibernate-core:jar:5.4.15.Final:compile
    [INFO] |  +- org.jboss.logging:jboss-logging:jar:3.3.2.Final:compile
    [INFO] |  +- org.javassist:javassist:jar:3.24.0-GA:compile
    [INFO] |  +- net.bytebuddy:byte-buddy:jar:1.10.10:compile
    [INFO] |  +- antlr:antlr:jar:2.7.7:compile
    [INFO] |  +- org.jboss.spec.javax.transaction:jboss-transaction-api_1.2_spec:jar:1.1.1.Final:compile
    [INFO] |  +- org.jboss:jandex:jar:2.1.3.Final:compile
    [INFO] |  +- com.fasterxml:classmate:jar:1.5.1:compile
    [INFO] |  +- javax.activation:javax.activation-api:jar:1.2.0:compile
    [INFO] |  +- org.dom4j:dom4j:jar:2.1.3:compile
    [INFO] |  +- org.hibernate.common:hibernate-commons-annotations:jar:5.1.0.Final:compile
    [INFO] |  +- javax.xml.bind:jaxb-api:jar:2.3.1:compile
    [INFO] |  \- org.glassfish.jaxb:jaxb-runtime:jar:2.3.1:compile
    [INFO] |     +- org.glassfish.jaxb:txw2:jar:2.3.1:compile
    [INFO] |     +- com.sun.istack:istack-commons-runtime:jar:3.0.7:compile
    [INFO] |     +- org.jvnet.staxex:stax-ex:jar:1.8:compile
    [INFO] |     \- com.sun.xml.fastinfoset:FastInfoset:jar:1.2.15:compile
    [INFO] \- org.hibernate.javax.persistence:hibernate-jpa-2.1-api:jar:1.0.2.Final:compile
    [INFO] ------------------------------------------------------------------------
    [INFO] BUILD SUCCESS
    [INFO] ------------------------------------------------------------------------
    [INFO] Total time: 0.927 s
    [INFO] Finished at: 2020-09-26T10:23:46-04:00
    [INFO] ------------------------------------------------------------------------

现在 [INFO] | +- javax.persistence:javax.persistence-api:jar:2.2:compile 行不存在 - 实际上我们要求 Maven 使用 org.hibernate.javax.persistence:hibernate-jpa-2.1-api:jar:1.0.2.Final:compile。

【讨论】：

“解决传递依赖冲突时”非常具有误导性。这里没有依赖冲突。就 Maven 而言，javax.persistence-api 和 hibernate-jpa-2.1-api 没有任何关系
我同意，这不适用于这里，我提供了一般信息，将更正。谢谢。