最近为了配合docker 容器平台的工作，实现一个eclipse插件，领导希望的功能是，右键点击项目提供一个war包commit的按钮，点击按钮后，自动调用eclipse的打包过程，输出war包，最终将war包上传到服务端，实现自动化的快速部署。

好了，功能如上，在原有插件的基础上加了相应的菜单，在获取项目的过程就不在累述，最后调用的打包过程如下：

public static  void exportWar(IProject webProject) throws CoreException {		webProject.build(IncrementalProjectBuilder.FULL_BUILD, null);	    WebComponentExportDataModelProvider modelProvider = new WebComponentExportDataModelProvider();	    IDataModel dataModel = DataModelFactory.createDataModel(modelProvider);	    String projectName = webProject.getName();        //war包的位置	    String destination_string = webProject.getLocation().append(projectName).addFileExtension("war").toOSString();         //datamodel的相关参数设置	    dataModel.setStringProperty(IJ2EEComponentExportDataModelProperties.ARCHIVE_DESTINATION, destination_string);	    dataModel.setStringProperty(IJ2EEComponentExportDataModelProperties.PROJECT_NAME, projectName);	    dataModel.setProperty(IJ2EEComponentExportDataModelProperties.COMPONENT, ComponentCore.createComponent(webProject));//	    dataModel.setBooleanProperty(IJ2EEComponentExportDataModelProperties.EXPORT_SOURCE_FILES, false);//	    dataModel.setBooleanProperty(IJ2EEComponentExportDataModelProperties.OVERWRITE_EXISTING, true);	    IDataModelOperation modelOperation = dataModel.getDefaultOperation();	    try {            //执行打包	        modelOperation.execute(new NullProgressMonitor(), null);	    } catch (org.eclipse.core.commands.ExecutionException e) {			e.printStackTrace();		}	}

如上代码，我看到某些方法，需要的类基本都在eclipse目录下的plugin下面，因此，就想当然的将所有需要的jar包直接拷贝到了插件项目下的lib下，并且加入了buildpath，乍看之下项目已经不报错了，一般来说，就可以进行操作了，使用eclipse的debug的方式，启动了插件，创建一个dynamic web project，然后右键导出 然后就出错了，一个很奇怪的错误，错误没有保存，但是最终的错误如下

org.eclipse.wst.common.modulecore.ModuleCoreNature cannot cast org.eclipse.wst.common.modulecore.ModuleCoreNature

跟踪代码发现，这里是在dataModel.setProperty()中，有个预处理的过程，其中有一部强转，爱强转的时候报了如上错误。

解决思路，一开始以为，我获取project的方式是不是有问题，拿到的project不是web项目，后来发现，取project的方法都是一样，直接通过workspace类获取，所以没有你问题，实在找不到解决办法，发现aws的eclipse插件有类似的功能，从github上下载下来看了下代码，发现他插件的处理方式几乎是一样的

public static IPath exportProjectToWar(IProject project, IPath directory) {        File tempFile;        try {            tempFile = File.createTempFile("aws-eclipse-", ".war", directory.toFile());        } catch (IOException e) {            e.printStackTrace();            throw new RuntimeException("Unable to create web application archive: " + e.getMessage(), e);        }        return exportProjectToWar(project, directory, tempFile.getName());    }    public static IPath exportProjectToWar(IProject project, IPath directory, String fileName) {        IDataModel dataModel = DataModelFactory.createDataModel(new WebComponentExportDataModelProvider());        if (directory.toFile().exists() == false) {            if (directory.toFile().mkdirs() == false) {                throw new RuntimeException("Unable to create temp directory for web application archive.");            }        }        String filename = new File(directory.toFile(), fileName).getAbsolutePath();        dataModel.setProperty(IJ2EEComponentExportDataModelProperties.ARCHIVE_DESTINATION, filename);        dataModel.setProperty(IJ2EEComponentExportDataModelProperties.PROJECT_NAME, project.getName());        try {            IDataModelOperation operation = dataModel.getDefaultOperation();            operation.execute(new NullProgressMonitor(), null);        } catch (ExecutionException e) {            // TODO: better error handling            e.printStackTrace();            throw new RuntimeException("Unable to create web application archive: " + e.getMessage(), e);        }        return new Path(filename);    }

然后问题就卡这里，后来终于发现问题的所在，在aws的项目中，Plug-in Dependences中的包含了所有eclipse的相关的依赖，具体如下

Manifest-Version: 1.0Bundle-ManifestVersion: 2Bundle-Name: AWS Elastic Beanstalk Eclipse PluginBundle-SymbolicName: com.amazonaws.eclipse.elasticbeanstalk;singleton:=trueBundle-Version: 1.0.0.qualifierBundle-Activator: com.amazonaws.eclipse.elasticbeanstalk.ElasticBeanstalkPluginBundle-Vendor: Amazon Web ServicesRequire-Bundle: org.eclipse.ui, org.eclipse.core.filesystem;bundle-version="1.2.0", org.eclipse.core.runtime;bundle-version="3.4.0", org.eclipse.core.resources;bundle-version="3.4.0", org.eclipse.jst.j2ee;bundle-version="1.1.0", org.eclipse.jst.j2ee.web;bundle-version="1.1.0", org.eclipse.jst.server.core;bundle-version="1.2.0", org.eclipse.wst.common.core;bundle-version="1.1.0", org.eclipse.wst.common.frameworks;bundle-version="1.1.0", org.eclipse.wst.server.core;bundle-version="1.1.0", org.eclipse.jdt.core;bundle-version="3.4.0", org.eclipse.jdt.launching;bundle-version="3.4.0", com.amazonaws.eclipse.core;bundle-version="2.3.1", com.amazonaws.eclipse.ec2;bundle-version="1.1.0", com.amazonaws.eclipse.sdk.ui;bundle-version="2.1.0", org.eclipse.core.databinding;bundle-version="1.2.0", org.eclipse.core.databinding.beans;bundle-version="1.2.0", org.eclipse.jface.databinding;bundle-version="1.3.0", org.eclipse.jface.text;bundle-version="3.4.0", org.eclipse.wst.common.project.facet.core;bundle-version="1.3.0", org.eclipse.debug.ui;bundle-version="3.4.0", org.eclipse.wst.server.ui;bundle-version="1.1.0", org.eclipse.core.net;bundle-version="1.2.0", org.eclipse.ui.forms;bundle-version="3.3.0", org.eclipse.jst.j2ee.ejb;bundle-version="1.1.0", org.eclipse.ui.navigator;bundle-version="3.2.0", com.jcraft.jsch;bundle-version="0.1.41"Bundle-RequiredExecutionEnvironment: J2SE-1.5Export-Package: com.amazonaws.eclipse.elasticbeanstalk.server.ui, com.amazonaws.eclipse.elasticbeanstalk.deployBundle-ClassPath: ., src/, lib/jgit/jgit-1.3.0-aws-git-push.jarBundle-ActivationPolicy: lazy

而我的项目中eclipse相关的添加方式不一样

Manifest-Version: 1.0Bundle-ManifestVersion: 2Bundle-Name: Sina App Engine Eclipse Plug-inBundle-SymbolicName: com.sina.sae.eclipse; singleton:=trueBundle-Version: 1.1.0Bundle-Vendor: SinaRequire-Bundle: org.eclipse.ui, org.eclipse.core.runtime, org.eclipse.jdt.core, org.eclipse.core.resources, org.eclipse.jdt.ui,Bundle-RequiredExecutionEnvironment: JavaSE-1.7Bundle-ActivationPolicy: lazyImport-Package: org.eclipse.ui.partBundle-Activator: com.sina.sae.eclipse.SAEPluginBundle-ClassPath: lib/sequence-library-1.0.1.jar, lib/sqljet-1.1.0.jar, lib/svnkit-1.7.4.jar, lib/svnkit-cli-1.7.4.jar, lib/svnkit-javahl16-1.7.4.jar, lib/trilead-ssh2-1.0.0-build214.jar, lib/org.eclipse.jst.j2ee_1.1.850.v201506041749.jar, lib/org.eclipse.jst.j2ee.web_1.1.850.v201503311656.jar, lib/org.eclipse.ui.workbench_3.107.0.v20150825-2206.jar, lib/org.eclipse.wst.common.frameworks_1.2.200.v201304241450.jar, lib/org.eclipse.wst.common.modulecore_1.2.401.v201408132036.jar, lib/org.eclipse.jem.util_2.1.200.v201404021757.jar, lib/org.eclipse.wst.common.emfworkbench.integration_1.2.101.v201107081800.jar, lib/org.eclipse.emf.common_2.11.0.v20150805-0538.jar, lib/org.eclipse.emf.ecore_2.11.1.v20150805-0538.jar, lib/org.eclipse.emf.ecore.xmi_2.11.1.v20150805-0538.jar, lib/org.eclipse.jst.j2ee.core_1.3.200.v201505041449.jar, lib/org.eclipse.wst.common.core_1.2.0.v200908251833.jar, lib/org.eclipse.wst.common.project.facet.core_1.4.300.v201111030423.jar, .

注意aws中的方式，是在Require-Bundle: 中添加需要的模块，而我直接在Bundle-ClassPath中添加了eclipse的相关模块（其实这里是添加外部引用类的，不能添加eclipse相关的类），后来也采用了aws的所示的方式将依赖重新引用，在此debug就没事了，war包能正常输出了