Maven使用本地依赖并获取同步:javax/NoClassDefFoundError/Synchronization

Question

我编写了一个简单的mvc框架，名为symphony-mvc，然后运行maven install将jar放入本地maven存储库中。但是当我在一个web项目中使用它时，我得到了这个错误。

java.lang.NoClassDefFoundError: javax/transaction/Synchronization
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:760)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at org.apache.catalina.loader.WebappClassLoaderBase.findClassInternal(WebappClassLoaderBase.java:2267)
at org.apache.catalina.loader.WebappClassLoaderBase.findClass(WebappClassLoaderBase.java:803)
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1244)
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1109)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:348)
at xyz.imwyy.symphony.util.ClassUtil.loadClass(ClassUtil.java:41)
at xyz.imwyy.symphony.util.ClassUtil.doAddClass(ClassUtil.java:124)
at xyz.imwyy.symphony.util.ClassUtil.getClassSet(ClassUtil.java:75)
at xyz.imwyy.symphony.helper.ClassHelper.<clinit>(ClassHelper.java:20)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:348)
at xyz.imwyy.symphony.util.ClassUtil.loadClass(ClassUtil.java:41)
at xyz.imwyy.symphony.SymphonyLoader.init(SymphonyLoader.java:27)
at xyz.imwyy.symphony.DispatcherServlet.init(DispatcherServlet.java:40)
at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1183)
at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1099)
at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:989)
at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:4920)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5230)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:752)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:728)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:734)
at org.apache.catalina.startup.HostConfig.manageApp(HostConfig.java:1702)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:300)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:456)
at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:405)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:300)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
at javax.management.remote.rmi.RMIConnectionImpl.doOperation(RMIConnectionImpl.java:1468)
at javax.management.remote.rmi.RMIConnectionImpl.access$300(RMIConnectionImpl.java:76)
at javax.management.remote.rmi.RMIConnectionImpl$PrivilegedOperation.run(RMIConnectionImpl.java:1309)
at javax.management.remote.rmi.RMIConnectionImpl.doPrivilegedOperation(RMIConnectionImpl.java:1401)
at javax.management.remote.rmi.RMIConnectionImpl.invoke(RMIConnectionImpl.java:829)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:323)
at sun.rmi.transport.Transport$1.run(Transport.java:200)
at sun.rmi.transport.Transport$1.run(Transport.java:197)
at java.security.AccessController.doPrivileged(Native Method)
at sun.rmi.transport.Transport.serviceCall(Transport.java:196)
at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:568)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:826)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$256(TCPTransport.java:683)
at java.security.AccessController.doPrivileged(Native Method)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:682)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)

在symphony-mvc框架中，我使用ClassUtil加载类，但是所有需要加载的类都是NoClassDefFoundError。我没有用过jta，为什么要告诉我NoClassDefFoundError:javax/transaction/Synchronization？顺便说一句，我已经把jar放到了WEB-INF/lib中。

这是symphony中的pom.xml -mvc

<groupId>xyz.imwyy</groupId>
<artifactId>symphony-mvc</artifactId>
<version>3.3</version>

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <configuration>
                <source>1.8</source>
                <target>1.8</target>
            </configuration>
        </plugin>
    </plugins>
</build>

<dependencies>
    <!-- Servlet -->
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>javax.servlet-api</artifactId>
        <version>4.0.0-b01</version>
        <scope>provided</scope>
    </dependency>

    <!-- JSP -->
    <dependency>
        <groupId>javax.servlet.jsp</groupId>
        <artifactId>jsp-api</artifactId>
        <version>2.2</version>
        <scope>provided</scope>
    </dependency>

    <!-- JSTL -->
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>jstl</artifactId>
        <version>1.2</version>
        <scope>runtime</scope>
    </dependency>

    <!--SLF4J-->
    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-log4j12</artifactId>
        <version>1.7.7</version>
    </dependency>

    <!--Mysql -->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>6.0.6</version>
        <scope>runtime</scope>
    </dependency>

    <!--Jackson json-->
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>2.8.8</version>
    </dependency>

    <!--Apache Commons Lang-->
    <dependency>
        <groupId>org.apache.commons</groupId>
        <artifactId>commons-lang3</artifactId>
        <version>3.5</version>
    </dependency>

    <!--Apache Commons Collections-->
    <dependency>
        <groupId>org.apache.commons</groupId>
        <artifactId>commons-collections4</artifactId>
        <version>4.1</version>
    </dependency>

    <!--Apache Commons DbUtils-->
    <dependency>
        <groupId>commons-dbutils</groupId>
        <artifactId>commons-dbutils</artifactId>
        <version>1.6</version>
    </dependency>

    <!--Apache DBCP -->
    <dependency>
        <groupId>org.apache.commons</groupId>
        <artifactId>commons-dbcp2</artifactId>
        <version>2.0.1</version>
    </dependency>

</dependencies>

以下是web项目中的pom.xml

<groupId>xyz.imwyy</groupId>
<artifactId>symphony-test</artifactId>
<version>1.0-SNAPSHOT</version>


<dependencies>
    <dependency>
        <groupId>xyz.imwyy</groupId>
        <artifactId>symphony-mvc</artifactId>
        <version>3.3</version>
    </dependency>
</dependencies>

谢谢。

Answer 1

您并没有添加所有的依赖jars。

解决这个问题有三种方法：

• 手动添加jar -添加所有jar symphony-mvc基于
• 手动添加jar，但创建包含所有依赖项的jar(例如，查看shade插件)
• 在项目中添加maven依赖项-mvc，这将自动获得所有需要的jar(推荐的shade

Answer 2

您需要将jar添加到包含缺少的类(javax/transaction/Synchronization)的依赖项中。这个类不一定要在代码中直接调用，而是由您使用的某个框架间接调用。