我正在使用Eclipse Kepler的Export控件构建一个项目几年。我遇到了一些问题，试图直接跳到我的最终配置（Java 8，Tomcat 8，CXF，并使用Maven进行构建），所以我试图这样做，而且我已经被困了两天。
我正在使用Eclipse Mars.2版本（4.5.2）。
由于历史原因，我有两个项目，MyImpl项目包含所有业务逻辑（也是远程Web服务的客户端/使用者，因此是CXF），以及MyWebApp，一个struts 1动态Web项目。在Java 7 / Tomcat 7中运行良好。我正在尝试介绍Maven，首先进入MyImpl项目，然后进入MyWebApp项目，最后构建Web服务客户端代码。
我将源代码重新排列为maven方式（/ src / main / java，/ src / test / java等）然后我添加了一个包含MyImpl项目所有依赖项的POM.xml。 MyImpl项目构建得很好，MyWebApp项目在Eclipse中引用了MyImpl项目，所以这也很好。一切都建立，没有红色的X.我们的测试用例现在还没有很好地开发，所以我无法运行它们。
当我尝试在Eclipse内部运行Tomcat 7时，Servers选项卡显示Tomcat 7服务器下的MyWebApp项目，但它没有像之前那样在MyWebApp项目下显示MyImpl项目。是的，Java Build Path / Projects显示MyWebApp项目依赖于MyImpl项目。否则它不会建立。
Tomcat无法启动NoClassDefFoundError：
Jun 08, 2016 4:48:55 PM org.apache.catalina.core.ContainerBase startInternal
SEVERE: A child container failed during start
java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/WebStarWebApp]]
at java.util.concurrent.FutureTask.report(FutureTask.java:122)
at java.util.concurrent.FutureTask.get(FutureTask.java:188)
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1123)
at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:816)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1575)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1565)
at java.util.concurrent.FutureTask.run(FutureTask.java:262)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/MyWebApp]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
... 6 more
Caused by: java.lang.NoClassDefFoundError: com/mycompany/mygroup/myproject/common/util/DB_Exception
at java.lang.Class.getDeclaredFields0(Native Method)
...
在MyImpl项目中定义了DB_Exception。
如果我双击服务器，单击“打开启动配置”，单击“类路径”选项卡，我会看到Bootstrap条目下的JRE系统库，以及bootstrap.jar，tomcat-juli.jar和tools.jar在用户条目下。如果我将MyWebApp项目添加到用户条目并启动服务器，则会出现类加载器异常：
Jun 08, 2016 5:20:54 PM org.apache.catalina.core.ApplicationContext log
SEVERE: StandardWrapper.Throwable
java.lang.LinkageError: loader constraint violation: loader (instance of sun/misc/Launcher$AppClassLoader) previously initiated loading for a different type with name "mycompany/common/logging/ISmLog"
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:800)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)
at java.net.URLClassLoader.access$100(URLClassLoader.java:71)
at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:800)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)
at java.net.URLClassLoader.access$100(URLClassLoader.java:71)
at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
<stack trace through initialization code>
at org.apache.struts.action.ActionServlet.initModulePlugIns(ActionServlet.java:1158)
at org.apache.struts.action.ActionServlet.init(ActionServlet.java:473)
at javax.servlet.GenericServlet.init(GenericServlet.java:158)
at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1284)
at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1197)
at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:1087)
at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:5231)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5518)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1575)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1565)
at java.util.concurrent.FutureTask.run(FutureTask.java:262)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)
如果不是将MyWebApp项目添加到运行配置中，我只添加MyImpl.jar（挖掘MyImpl项目，选择MyImpl \ target \ MyImpl-1.0.jar），我仍然得到NoClassDefFoundError：
Jun 08, 2016 5:32:07 PM org.apache.catalina.core.ApplicationContext log
SEVERE: StandardWrapper.Throwable
java.lang.NoClassDefFoundError: mycompany/myproject/logging/InstrRecord
at com.mycompany.myproject.struts.plugins.MyImpl_PlugIn.init(MyImpl_PlugIn.java:55)
at org.apache.struts.action.ActionServlet.initModulePlugIns(ActionServlet.java:1158)
at org.apache.struts.action.ActionServlet.init(ActionServlet.java:473)
at javax.servlet.GenericServlet.init(GenericServlet.java:158)
at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1284)
at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1197)
at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:1087)
at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:5231)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5518)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1575)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1565)
at java.util.concurrent.FutureTask.run(FutureTask.java:262)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.ClassNotFoundException: mycompany/myproject/logging/InstrRecord
at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
这是一个全新的工作区和新的代码库导入。