Tomcat + JPA + MySQL：java.lang.NoClassDefFoundError：javax / persistence / Persistence

131

奥古斯丁·博肯

作为学校项目的一部分，我必须将Java REST API连接到MySql数据库。

不幸的是，我似乎无法实例化EntityManagerFactory。我已经尝试过在线找到解决方案，但无法解决问题。

我有几个需要存储在数据案例中的类，并且我已经使用注释来描述它们（基本上是@Entity注释，@ ManyToOne等，当然还有@Id和@GeneratedValue

我的自定义EntityManager：

import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence;

public class NatagoraEntityManager {
    private EntityManager manager;
    public NatagoraEntityManager(){
        EntityManagerFactory factory =  Persistence.createEntityManagerFactory("MyPersistenceUnit");
        manager = factory.createEntityManager();
    }
}

我的RestController：

@Path("/helloworld")
public class HelloWorld {

    private NatagoraEntityManager manager;
    public HelloWorld(){
        //Without this line it works fine
        manager = new NatagoraEntityManager();
    }


    // The Java method will process HTTP GET requests
    @GET
    // The Java method will produce content identified by the MIME Media type "text/plain"
    @Produces("text/plain")
    public String getClichedMessage() {
        // Return some cliched textual content
        return "Hello World";
    }
}

我的persistence.xml：

<?xml version="1.0" encoding="UTF-8"?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence" version="2.0">

    <persistence-unit name="MyPersistenceUnit">
        <properties>

            <property name="openjpa.ConnectionURL" value="jdbc:mysql://111.111.111.111:3306/bdname/"/>
            <property name="openjpa.ConnectionDriverName" value="com.mysql.jdbc.Driver"/>
            <property name="openjpa.ConnectionUserName" value="login"/>
            <property name="openjpa.ConnectionPassword" value="password"/>
            <property name="openjpa.Log" value="DefaultLevel=TRACE, Tool=INFO"/>
            <property name="openjpa.jdbc.SynchronizeMappings" value="buildSchema(ForeignKeys=true)"/>
        </properties>
    </persistence-unit>
</persistence>

我的pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<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/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>JAXRS-Example</groupId>
    <artifactId>JAXRS-Example</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>war</packaging>

    <dependencies>
        <dependency>
            <groupId>com.sun.jersey</groupId>
            <artifactId>jersey-server</artifactId>
            <version>1.19</version>
        </dependency>
        <dependency>
            <groupId>com.sun.jersey</groupId>
            <artifactId>jersey-servlet</artifactId>
            <version>1.19</version>
        </dependency>
        <dependency>
            <groupId>com.owlike</groupId>
            <artifactId>genson</artifactId>
            <version>0.99</version>
        </dependency>
        <dependency>
            <groupId>com.sun.jersey</groupId>
            <artifactId>jersey-client</artifactId>
            <version>1.19</version>
        </dependency>
        <dependency>
            <groupId>com.sun.jersey</groupId>
            <artifactId>jersey-json</artifactId>
            <version>1.9</version>
        </dependency>
        <dependency>
            <groupId>javax.persistence</groupId>
            <artifactId>persistence-api</artifactId>
            <version>[1.0.2,)</version>
        </dependency>
        <dependency>
            <groupId>org.apache.openjpa</groupId>
            <artifactId>openjpa-persistence-jdbc</artifactId>
            <version>[1.0.1,)</version>
        </dependency>
    </dependencies>

    <build>
        <sourceDirectory>src</sourceDirectory>
        <plugins>
            <plugin>
                <artifactId>maven-war-plugin</artifactId>
                <version>2.6</version>
                <configuration>
                    <warSourceDirectory>WebContent</warSourceDirectory>
                    <failOnMissingWebXml>false</failOnMissingWebXml>
                </configuration>
            </plugin>
            <plugin>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.3</version>
                <configuration>
                    <source>1.7</source>
                    <target>1.7</target>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

最后，这是我收到的错误：

 java.lang.NoClassDefFoundError: javax/persistence/Persistence
    at DAL.NatagoraEntityManager.<init>(NatagoraEntityManager.java:10)
    at main.java.HelloWorld.<init>(HelloWorld.java:20)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
    at com.sun.jersey.server.spi.component.ResourceComponentConstructor._construct(ResourceComponentConstructor.java:245)
    at com.sun.jersey.server.spi.component.ResourceComponentConstructor.construct(ResourceComponentConstructor.java:233)
    at com.sun.jersey.server.impl.resource.PerRequestFactory$PerRequest._getInstance(PerRequestFactory.java:182)
    at com.sun.jersey.server.impl.resource.PerRequestFactory$AbstractPerRequest.getInstance(PerRequestFactory.java:144)
    at com.sun.jersey.server.impl.application.WebApplicationContext.getResource(WebApplicationContext.java:239)
    at com.sun.jersey.server.impl.uri.rules.ResourceClassRule.accept(ResourceClassRule.java:83)
    at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:147)
    at com.sun.jersey.server.impl.uri.rules.RootResourceClassesRule.accept(RootResourceClassesRule.java:84)
    at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1542)
    at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1473)
    at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1419)
    at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1409)
    at com.sun.jersey.spi.container.servlet.WebComponent.service(WebComponent.java:409)
    at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:558)
    at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:733)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:292)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:94)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:504)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:620)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:502)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1132)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:684)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1539)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1495)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.ClassNotFoundException: javax.persistence.Persistence
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1339)
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1167)
    ... 43 more

如果您在某个地方找到答案，我将不胜感激，因为几个小时以来我一直在解决这个问题。如果您需要更多信息，我们很乐意告诉您您需要什么。

谢谢！

编辑：这是我的project.iml文件的一部分，在这里我选择了JPA提供程序：

<facet type="jpa" name="JPA">
      <configuration>
        <setting name="validation-enabled" value="true" />
        <setting name="provider-name" value="OpenJPA" />
        <datasource-mapping />
        <deploymentDescriptor name="persistence.xml" url="file://$MODULE_DIR$/src/META-INF/persistence.xml" />
      </configuration>
    </facet>

EDIT2：更改了pom.xml

EDIT3：这是我的WAR文件中包含的jar：

奥古斯丁·博肯

为了使该项目正常工作，进行了很多更改。

现在是我的pom.xml：

<?xml version="1.0" encoding="UTF-8"?>
<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/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>JAXRS-Example</groupId>
    <artifactId>JAXRS-Example</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>war</packaging>
    <repositories>
        <repository>
            <id>eclipselink</id>
            <url>http://www.eclipse.org/downloads/download.php?r=1&amp;nf=1&amp;file=/rt/eclipselink/maven.repo/</url>
        </repository>
    </repositories>
    <dependencies>
        <dependency>
            <groupId>org.eclipse.persistence</groupId>
            <artifactId>eclipselink</artifactId>
            <version>2.7.0</version>
        </dependency>
        <dependency>
            <groupId>javax.persistence</groupId>
            <artifactId>javax.persistence-api</artifactId>
            <version>2.2</version>
        </dependency>
        <dependency>
            <groupId>org.eclipse.persistence</groupId>
            <artifactId>org.eclipse.persistence.jpa</artifactId>
            <version>2.7.0</version>
        </dependency>
        <dependency>
            <groupId>com.sun.jersey</groupId>
            <artifactId>jersey-server</artifactId>
            <version>1.19</version>
        </dependency>
        <dependency>
            <groupId>com.sun.jersey</groupId>
            <artifactId>jersey-servlet</artifactId>
            <version>1.19</version>
        </dependency>
        <dependency>
            <groupId>com.owlike</groupId>
            <artifactId>genson</artifactId>
            <version>0.99</version>
        </dependency>
        <dependency>
            <groupId>com.sun.jersey</groupId>
            <artifactId>jersey-client</artifactId>
            <version>1.19</version>
        </dependency>
        <dependency>
            <groupId>com.sun.jersey</groupId>
            <artifactId>jersey-json</artifactId>
            <version>1.9</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.44</version>
        </dependency>
    </dependencies>

    <build>
        <sourceDirectory>src</sourceDirectory>
        <plugins>
            <plugin>
                <artifactId>maven-war-plugin</artifactId>
                <version>2.6</version>
                <configuration>
                    <warSourceDirectory>WebContent</warSourceDirectory>
                    <failOnMissingWebXml>false</failOnMissingWebXml>
                </configuration>
            </plugin>
            <plugin>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.3</version>
                <configuration>
                    <source>1.7</source>
                    <target>1.7</target>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

还有我的persistence.xml

<?xml version="1.0" encoding="UTF-8"?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence" version="2.0">

    <persistence-unit name="MyPersistenceUnit">
        <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
        <exclude-unlisted-classes>false</exclude-unlisted-classes>
        <properties>
            <property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/bdname"/>
            <property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver"/>
            <property name="javax.persistence.jdbc.user" value="login"/>
            <property name="javax.persistence.jdbc.password" value="password"/>
            <property name="javax.persistence.schema-generation.database.action" value="create"/>
        </properties>
    </persistence-unit>
</persistence>

我还必须更改项目的整个结构，因为我有一些包未包含在main.java中。现在，一切都在此程序包中组织，而不是在外部。

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