java - X.jar 中的 Maven JarClassLoader : Warning:Foo. 类被 Y.jar 隐藏(具有不同的字节码)

Question

一旦我将 java.mail 支持添加到我的项目中:

     <dependency>
        <groupId>javax.mail</groupId>
        <artifactId>mail</artifactId>
        <version>1.4.1</version>
    </dependency>
    <dependency>
        <groupId>javax.activation</groupId>
        <artifactId>activation</artifactId>
        <version>1.1.1</version>
    </dependency>

我开始收到大量这样的警告消息(当我运行构建的 jar 时):

JarClassLoader: Warning: javax/mail/Address.class in lib/mail-1.4.1.jar is hidden by lib/geronimo-javamail_1.4_spec-1.7.1.jar (with different bytecode)
JarClassLoader: Warning: javax/mail/AuthenticationFailedException.class in lib/mail-1.4.1.jar is hidden by lib/geronimo-javamail_1.4_spec-1.7.1.jar (with differ
ent bytecode)
JarClassLoader: Warning: javax/mail/Authenticator.class in lib/mail-1.4.1.jar is hidden by lib/geronimo-javamail_1.4_spec-1.7.1.jar (with different bytecode)
JarClassLoader: Warning: javax/mail/BodyPart.class in lib/mail-1.4.1.jar is hidden by lib/geronimo-javamail_1.4_spec-1.7.1.jar (with different bytecode)
JarClassLoader: Warning: javax/mail/EventQueue.class in lib/mail-1.4.1.jar is hidden by lib/geronimo-javamail_1.4_spec-1.7.1.jar (with different bytecode)
JarClassLoader: Warning: javax/mail/FetchProfile$Item.class in lib/mail-1.4.1.jar is hidden by lib/geronimo-javamail_1.4_spec-1.7.1.jar (with different bytecode
)

我的程序运行良好(并且可以正常发送电子邮件)，但我不想要所有这些数百个 JarClassLoader 警告...

知道如何让我的控制台日志恢复平静吗？

---

更新:感谢下面 Jigar Joshi 的提示，我发现不需要的 geronimo-javamail_1.4_spec-1.7.1.jar 来自 org.apache.cxf:cxf-api:jar:2.7.1 :compile，所以我添加了一个排除:

   <dependency> 
        <groupId>org.apache.cxf</groupId>
        <artifactId>cxf-api</artifactId>
        <version>2.7.1</version>
        <exclusions>
          <exclusion>  
           <groupId>org.apache.geronimo.specs</groupId>
           <artifactId>geronimo-javamail_1.4_spec</artifactId>
         </exclusion>
       </exclusions> 
    </dependency>

而且 mvn dependency:tree 命令不再将“geronimo”显示为依赖项，但是当我运行新生成的 jar(从干净构建!)时，我仍然收到所有这些警告

其他建议？

---

更新 2:这是我的 pom.xml 中的依赖项部分:

<dependencies>
  <dependency>
    <groupId>junit</groupId>
    <artifactId>junit</artifactId>
    <version>3.8.1</version>
    <scope>test</scope>
  </dependency>


  <dependency>
    <groupId>org.apache.cxf</groupId>
    <artifactId>cxf-rt-frontend-jaxws</artifactId>
    <version>2.7.1</version>
    <type>jar</type>
    <scope>runtime</scope>
  </dependency>
  <dependency>
    <groupId>org.apache.cxf</groupId>
    <artifactId>cxf-rt-transports-http</artifactId>
    <version>2.7.1</version>
    <type>jar</type>
    <scope>runtime</scope>
  </dependency>
  <dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-web</artifactId>
    <version>3.0.7.RELEASE</version>
  </dependency>


  <dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>5.1.26</version>
  </dependency>
  <dependency>
    <groupId>org.hibernate</groupId>
    <artifactId>hibernate-core</artifactId>
    <version>4.2.6.Final</version>
  </dependency>
  <dependency> 
    <groupId>org.apache.cxf</groupId>
    <artifactId>cxf-api</artifactId>
    <version>2.7.1</version>
    <exclusions>
      <exclusion>
    <groupId>org.apache.geronimo.specs</groupId>
    <artifactId>geronimo-javamail_1.4_spec</artifactId>
      </exclusion>
    </exclusions> 
  </dependency>
  <dependency>
    <groupId>org.apache.cxf</groupId>
    <artifactId>cxf-rt-transports-http</artifactId>
    <version>2.7.1</version>
    <type>jar</type>
  </dependency>

  <dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>servlet-api</artifactId>
    <version>2.5</version>
  </dependency>

  <dependency> 
    <groupId>javax.mail</groupId>
    <artifactId>mail</artifactId>
    <version>1.4.1</version>
  </dependency>
  <dependency>
    <groupId>javax.activation</groupId>
    <artifactId>activation</artifactId>
    <version>1.1.1</version>
  </dependency>

</dependencies>

Answer 1

那个警告说你有来自多个 jar 的相同类，所以它可能会在运行时引起问题

例如:

JarClassLoader: Warning: javax/mail/EventQueue.class in lib/mail-1.4.1.jar is hidden by lib/geronimo-javamail_1.4_spec-1.7.1.jar (with different bytecode)

我假设您正在寻找来自 mail-1.4.1.jar 的类(class)而不是来自 geronimo-javamail_1.4_spec-1.7.1.jar例如

你必须排除这个不需要的 jar，这样它就不会在类路径中可用，或者通过使用 <exclusions>或 <optional>标签，它可能来自其他 jar 的依赖

执行mvn dependency:tree从它来的地方追踪它 <exclude>它

---

另见

• <optional> & <exclusions>