java.lang.NoClassDefFoundError : javax/persistence/TableGenerators

Question

我正在尝试使用 hibernate JPA 到 Tomcat 中开发后端应用程序。从现在开始，它在使用 JPA 功能的测试中运行良好，并且没有 JPA 服务的第一个版本现在正在运行(文件上传、下载等)。

现在我正在集成 JPA 以应用我们需要的所有功能，但是，即使所有测试工作正常(包括服务测试)，当我将 Postman 的请求提交到本地服务器。

这是异常(exception):

javax.servlet.ServletException: org.glassfish.jersey.server.ContainerException: java.lang.NoClassDefFoundError: javax/persistence/TableGenerators

这是我的 pom.xml

    <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.itvcvr</groupId>
  <artifactId>RESTfullApp</artifactId>
  <packaging>war</packaging>
  <version>0.0.1-SNAPSHOT</version>
  <name>RESTfullApp Maven Webapp</name>
  <url>http://maven.apache.org</url>
  <dependencies>
    <!-- https://mvnrepository.com/artifact/junit/junit -->
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.12</version>
        <scope>test</scope>
    </dependency>

    <!-- https://mvnrepository.com/artifact/javax.servlet/javax.servlet-api -->
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>javax.servlet-api</artifactId>
        <version>4.0.1</version>
        <scope>provided</scope>
    </dependency>

    <!-- https://mvnrepository.com/artifact/javax.xml.bind/jaxb-api -->
    <dependency>
        <groupId>javax.xml.bind</groupId>
        <artifactId>jaxb-api</artifactId>
        <version>2.3.1</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/javax.activation/activation -->
    <dependency>
        <groupId>javax.activation</groupId>
        <artifactId>activation</artifactId>
        <version>1.1</version>
    </dependency>


    <!-- https://mvnrepository.com/artifact/org.apache.tomcat/tomcat-catalina -->
    <dependency>
        <groupId>org.apache.tomcat</groupId>
        <artifactId>tomcat-catalina</artifactId>
        <version>8.5.20</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.apache.tomcat/tomcat-jdbc -->
    <dependency>
        <groupId>org.apache.tomcat</groupId>
        <artifactId>tomcat-jdbc</artifactId>
        <version>9.0.30</version>
        <exclusions>
            <exclusion>
                <groupId>org.apache.tomcat</groupId>
                <artifactId>tomcat-juli</artifactId>
            </exclusion>
        </exclusions>
    </dependency>


    <!-- https://mvnrepository.com/artifact/javax.ws.rs/javax.ws.rs-api -->
    <dependency>
        <groupId>javax.ws.rs</groupId>
        <artifactId>javax.ws.rs-api</artifactId>
        <version>2.1.1</version>
    </dependency>


    <!-- https://mvnrepository.com/artifact/org.glassfish.jersey.core/jersey-server -->
    <dependency>
        <groupId>org.glassfish.jersey.core</groupId>
        <artifactId>jersey-server</artifactId>
        <version>2.29</version>
        <exclusions>
            <exclusion>
                <groupId>org.glassfish.hk2.external</groupId>
                <artifactId>jakarta.inject</artifactId>
            </exclusion>
        </exclusions>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.glassfish.jersey.containers/jersey-container-servlet -->
    <dependency>
        <groupId>org.glassfish.jersey.containers</groupId>
        <artifactId>jersey-container-servlet</artifactId>
        <version>2.29</version>
         <exclusions>
            <exclusion>
                <groupId>org.glassfish.hk2.external</groupId>
                <artifactId>jakarta.inject</artifactId>
            </exclusion>
        </exclusions>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.glassfish.jersey.containers/jersey-container-servlet-core -->
    <dependency>
        <groupId>org.glassfish.jersey.containers</groupId>
        <artifactId>jersey-container-servlet-core</artifactId>
        <version>2.29</version>
        <exclusions>
            <exclusion>
                <groupId>org.glassfish.hk2.external</groupId>
                <artifactId>jakarta.inject</artifactId>
            </exclusion>
        </exclusions>
    </dependency>


    <!-- https://mvnrepository.com/artifact/org.glassfish.jersey.media/jersey-media-multipart -->
    <dependency>
        <groupId>org.glassfish.jersey.media</groupId>
        <artifactId>jersey-media-multipart</artifactId>
        <version>2.29.1</version>
        <exclusions>
            <exclusion>
                <groupId>org.glassfish.jersey.core</groupId>
                <artifactId>jersey-common</artifactId>
            </exclusion>
        </exclusions>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.glassfish.jersey.inject/jersey-hk2 -->
    <dependency>
        <groupId>org.glassfish.jersey.inject</groupId>
        <artifactId>jersey-hk2</artifactId>
        <version>2.29.1</version>
        <exclusions>
            <exclusion>
                <groupId>org.glassfish.jersey.core</groupId>
                <artifactId>jersey-common</artifactId>
            </exclusion>
            <exclusion>
                <groupId>org.javassist</groupId>
                <artifactId>javassist</artifactId>
            </exclusion>
        </exclusions>
    </dependency>

    <!-- https://mvnrepository.com/artifact/javax.persistence/javax.persistence-api -->
    <dependency>
        <groupId>javax.persistence</groupId>
        <artifactId>javax.persistence-api</artifactId>
        <version>2.2</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.apache.tomee/javaee-api -->
    <dependency>
        <groupId>org.apache.tomee</groupId>
        <artifactId>javaee-api</artifactId>
        <version>7.0</version>
        <scope>provided</scope>
    </dependency>


    <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.16</version>
    </dependency>


    <!-- https://mvnrepository.com/artifact/org.hibernate.javax.persistence/hibernate-jpa-2.1-api -->
    <dependency>
        <groupId>org.hibernate.javax.persistence</groupId>
        <artifactId>hibernate-jpa-2.1-api</artifactId>
        <version>1.0.0.Final</version>
    </dependency>



    <!-- https://mvnrepository.com/artifact/org.hibernate/hibernate-entitymanager -->
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-entitymanager</artifactId>
        <version>5.4.3.Final</version>
        <exclusions>
            <exclusion>
                <groupId>org.hibernate</groupId>
                <artifactId>hibernate-core</artifactId>
            </exclusion>
            <exclusion>
                <groupId>net.bytebuddy</groupId>
                <artifactId>byte-buddy</artifactId>
            </exclusion>
        </exclusions>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.hibernate/hibernate-core -->
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-core</artifactId>
        <version>5.4.10.Final</version>
        <exclusions>
            <exclusion>
                <groupId>javax.xml.bind</groupId>
                <artifactId>jaxb-api</artifactId>
            </exclusion>
        </exclusions>
    </dependency>



  </dependencies>
  <build>
    <finalName>RESTfullApp</finalName>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.1</version>
            <configuration>
                <source>1.8</source>
                <target>1.8</target>
                <encoding>UTF-8</encoding>
            </configuration>
        </plugin>

            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-enforcer-plugin</artifactId>
                <version>1.4.1</version>
                <configuration>
                    <rules><dependencyConvergence/></rules>
                </configuration>
            </plugin>
    </plugins>
  </build>
</project>

并且在Entity Manager的生成过程中触发异常

em = Persistence.createEntityManagerFactory("testDb").createEntityManager();

JDBC驱动程序也在eEntity Manager实例之前注册

try {
        Class.forName("com.mysql.cj.jdbc.Driver");
} catch (ClassNotFoundException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}

我还使用插入强制来检查是否有任何依赖项在我的 pom.xml 中造成任何版本不兼容。

这是我从0开始配置的第一个项目，这个问题是我解决问题的最后资源。

谢谢大家:D

Answer 1

在大多数情况下，此错误表示类加载器找不到您的代码所依赖的类。

在您的例子中，名为 javax/persistence/TableGenerators 的类预计位于类路径中，但由于某些原因它不在类路径中。

TableGenerators 类打包在 javax.persistence-api-2.2.jar 文件中。

在 tomacat 上部署 .war 文件之前，请检查类路径上是否有所需的 jar - 输入 RESTfullApp.war 文件并查看 WEB-INF/lib 文件夹，即 javax.persistence -api-2.2.jar 必须存在，否则请修复您的 Maven 构建以实现此目的。

更新

还值得一提的是，Tomcat 中展开的 .war 文件夹 ($CATALINA_BASE/webapps/RESTfullApp) 必须具有相同的布局并包含您在 您的 .war 存档，检查 javax.persistence-api-2.2.jar 是否也在那里。

如果提到的 .jar 存在于类路径中，我还建议您检查 javax.persistence-api-2.2.jar 是否已损坏。

有时，maven 下载损坏的 .jar 存档，这可能会导致您看到的错误。至少，你可以尝试解压这个jar文件并检查解压这个jar文件时是否会出现任何错误。