如何编译引用底层webapp的额外系统包的Eclipse插件项目？

Question

我正在开发一个webapp，我在servlet上下文监听器中启动osgi框架（Eclipse Equinox版本3.10.0）。Webapp在Tomcat 8和Java7中运行。我已经开发并安装了2个简单的包，只要它们使用它们的内部类就可以正常工作。但是当我尝试将webapp包导入到system.package.extra配置的bundles中时，bundles无法解析这些包：

java.lang.Error: Unresolved compilation problems: 
    The import xxx.xxxxxxxx cannot be resolved

框架这样声明额外的系统包：

public void contextInitialized(ServletContextEvent cntxt) {
Iterator<FrameworkFactory> frameworkFactoryIt = ServiceLoader.load(FrameworkFactory.class).iterator();
boolean frameworkStarted = false;
while (frameworkFactoryIt.hasNext() && !frameworkStarted) {
  FrameworkFactory frameworkFactory = frameworkFactoryIt.next();
  Map<String, String> config = new HashMap<String, String>();
  config.put(Constants.FRAMEWORK_SYSTEMPACKAGES_EXTRA, "xxx.xxxxxxxx,...");
  config.put(Constants.FRAMEWORK_STORAGE, "/users/peveuve/osgi-cache");
  config.put(Constants.FRAMEWORK_STORAGE_CLEAN, "true");
  framework = frameworkFactory.newFramework(config);
  framework.start();
  ....

捆绑包清单如下所示：

Import-Package: org.osgi.framework;version="1.3.0",
 xxx.xxxxxxxx;resolution:=optional,

导入的包是可选的，以避免Eclipse插件项目中的错误。我不使用版本控制。

当列出框架标题时，我注意到导出包中的系统包和我的额外系统包之间有一个空格字符：

...,org.xml.sax.helpers, xxx.xxxxxxxx,...

由于它是由框架本身添加的，我想这不是问题，但谁知道呢。

以下是完整的堆栈跟踪：

!SESSION 2016-02-26 16:07:35.175 -----------------------------------------------
eclipse.buildId=unknown
java.version=1.7.0_79
java.vendor=Oracle Corporation
BootLoader constants: OS=win32, ARCH=x86_64, WS=win32, NL=fr_FR

!ENTRY com.amfinesoft.kheops.service.user 4 0 2016-02-26 16:07:35.176
!MESSAGE FrameworkEvent ERROR
!STACK 0
org.osgi.framework.ServiceException: Exception in com.amfinesoft.kheops.service.user.UserServiceFactory.getService()
    at org.eclipse.osgi.internal.serviceregistry.ServiceFactoryUse.factoryGetService(ServiceFactoryUse.java:222)
    at org.eclipse.osgi.internal.serviceregistry.ServiceFactoryUse.getService(ServiceFactoryUse.java:111)
    at org.eclipse.osgi.internal.serviceregistry.ServiceConsumer$2.getService(ServiceConsumer.java:45)
    at org.eclipse.osgi.internal.serviceregistry.ServiceRegistrationImpl.getService(ServiceRegistrationImpl.java:496)
    at org.eclipse.osgi.internal.serviceregistry.ServiceRegistry.getService(ServiceRegistry.java:461)
    at org.eclipse.osgi.internal.framework.BundleContextImpl.getService(BundleContextImpl.java:619)
    at com.amfinesoft.kheops.consumer.user.UserConsumerActivator.start(UserConsumerActivator.java:24)
    at org.eclipse.osgi.internal.framework.BundleContextImpl$3.run(BundleContextImpl.java:771)
    at org.eclipse.osgi.internal.framework.BundleContextImpl$3.run(BundleContextImpl.java:1)
    at java.security.AccessController.doPrivileged(Native Method)
    at org.eclipse.osgi.internal.framework.BundleContextImpl.startActivator(BundleContextImpl.java:764)
    at org.eclipse.osgi.internal.framework.BundleContextImpl.start(BundleContextImpl.java:721)
    at org.eclipse.osgi.internal.framework.EquinoxBundle.startWorker0(EquinoxBundle.java:936)
    at org.eclipse.osgi.internal.framework.EquinoxBundle$EquinoxModule.startWorker(EquinoxBundle.java:319)
    at org.eclipse.osgi.container.Module.doStart(Module.java:571)
    at org.eclipse.osgi.container.Module.start(Module.java:439)
    at org.eclipse.osgi.framework.util.SecureAction.start(SecureAction.java:454)
    at org.eclipse.osgi.container.ModuleContainer.applyDelta(ModuleContainer.java:717)
    at org.eclipse.osgi.container.ModuleContainer.resolveAndApply(ModuleContainer.java:491)
    at org.eclipse.osgi.container.ModuleContainer.resolve(ModuleContainer.java:437)
    at org.eclipse.osgi.container.ModuleContainer.resolve(ModuleContainer.java:427)
    at org.eclipse.osgi.container.Module.start(Module.java:416)
    at org.eclipse.osgi.container.ModuleContainer$ContainerStartLevel.incStartLevel(ModuleContainer.java:1582)
    at org.eclipse.osgi.container.ModuleContainer$ContainerStartLevel.incStartLevel(ModuleContainer.java:1562)
    at org.eclipse.osgi.container.ModuleContainer$ContainerStartLevel.doContainerStartLevel(ModuleContainer.java:1533)
    at org.eclipse.osgi.container.SystemModule.startWorker(SystemModule.java:242)
    at org.eclipse.osgi.container.Module.doStart(Module.java:571)
    at org.eclipse.osgi.container.Module.start(Module.java:439)
    at org.eclipse.osgi.container.SystemModule.start(SystemModule.java:172)
    at org.eclipse.osgi.internal.framework.EquinoxBundle.start(EquinoxBundle.java:393)
    at org.eclipse.osgi.internal.framework.EquinoxBundle.start(EquinoxBundle.java:412)
    at org.eclipse.osgi.launch.Equinox.start(Equinox.java:115)
    at com.amfinesoft.kheops.service.starter.OSGIServletContextListener.contextInitialized(OSGIServletContextListener.java:60)
    at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4812)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5255)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1408)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1398)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.Error: Unresolved compilation problems: 
    The import com.eclipsesource cannot be resolved
    The import com.eclipsesource cannot be resolved
    The import kheops cannot be resolved
    The import kheops cannot be resolved
    The import kheops cannot be resolved
    The import system cannot be resolved
    The type UserServiceImpl must implement the inherited abstract method UserServiceIntf.listOfUsers(KCommand, KBrowser)
    KCommand cannot be resolved to a type
    KCommand cannot be resolved to a type
    KBrowser cannot be resolved to a type
    JsonArray cannot be resolved to a type
    JsonArray cannot be resolved to a type
    The method getTrees() is undefined for the type DBUserFinder
    The method getTrees() is undefined for the type DBUserContainer
    JsonValue cannot be resolved
    Logger cannot be resolved
    KCommandProcessor cannot be resolved

    at com.amfinesoft.kheops.service.user.impl.UserServiceImpl.<init>(UserServiceImpl.java:7)
    at com.amfinesoft.kheops.service.user.UserServiceFactory.getService(UserServiceFactory.java:14)
    at com.amfinesoft.kheops.service.user.UserServiceFactory.getService(UserServiceFactory.java:1)
    at org.eclipse.osgi.internal.serviceregistry.ServiceFactoryUse$1.run(ServiceFactoryUse.java:212)
    at java.security.AccessController.doPrivileged(Native Method)
    at org.eclipse.osgi.internal.serviceregistry.ServiceFactoryUse.factoryGetService(ServiceFactoryUse.java:210)
    ... 41 more

你知道为什么会发生这样的错误吗？

当Eclipse插件项目引用来自底层Web应用程序的额外系统包时，如何编译它？

Answer 1

这根本不是OSGi错误。这是部署未正确编译的代码的结果。

Eclipse使用自己的名为ECJ的编译器，而不是来自JDK的javac，后者在遇到错误时的行为会有所不同。尽管javac将立即停止并不会生成任何输出，但ECJ会生成类文件作为输出。但是，如果您尝试运行这些类，您将看到以下消息：

java.lang.Error: Unresolved compilation problems: 
    The import xxx.xxxxxxxx cannot be resolved

关于“导入无法解析”的消息来自Java编译器。如果您查看IDE中的源代码，您应该会看到红色的X标记。

基本上，在尝试运行代码之前，您必须确保代码实际编译时没有错误。