如何解决错误Mwe2Launcher:无法找到名称的EClass

Question

我创建了一个Xpand生成器。在它的src/文件夹中，我定义了我的模型My.nn、模板和工作流。

这就是我的workflow.mwe2文件的样子：

module workflow.NeuralNetworksGenerator

import org.eclipse.emf.mwe.utils.*

var targetDir = "src-gen"
var fileEncoding = "Cp1252"
var modelPath = "src/model"

Workflow {
    component = org.eclipse.xtext.mwe.Reader {
        // lookup all resources on the classpath
        //useJavaClassPath = true

        // or define search scope explicitly
        path = modelPath

        // this class will be generated by the xtext generator 
        register = org.xtext.example.neuralnetworks.NeuralNetworksStandaloneSetup {}
        load = {
            slot = "systems"
            type = "System"
        }
    }

    component = org.eclipse.xpand2.Generator {
        expand = "templates::Template::main FOREACH systems"
        outlet = {
            path = targetDir
        }
        fileEncoding = fileEncoding
    }
}

当我试图以workflow.mwe2工作流的形式运行这个MWE2文件时，我会得到以下错误：

0    INFO  AbstractExpressionsUsingWorkflowComponent - No meta models configured, using JavaBeans as default.
75   ERROR Mwe2Launcher       - Problems running workflow workflow.NeuralNetworksGenerator: Couldn't find EClass for name 'System'.
java.lang.RuntimeException: Problems running workflow workflow.NeuralNetworksGenerator: Couldn't find EClass for name 'System'.
    at org.eclipse.emf.mwe2.launch.runtime.Mwe2Runner.run(Mwe2Runner.java:99)
    at org.eclipse.emf.mwe2.launch.runtime.Mwe2Runner.run(Mwe2Runner.java:73)
    at org.eclipse.emf.mwe2.launch.runtime.Mwe2Runner.run(Mwe2Runner.java:64)
    at org.eclipse.emf.mwe2.launch.runtime.Mwe2Runner.run(Mwe2Runner.java:55)
    at org.eclipse.emf.mwe2.launch.runtime.Mwe2Launcher.run(Mwe2Launcher.java:74)
    at org.eclipse.emf.mwe2.launch.runtime.Mwe2Launcher.main(Mwe2Launcher.java:35)
Caused by: org.eclipse.emf.mwe.core.WorkflowInterruptedException: Couldn't find EClass for name 'System'.
    at org.eclipse.xtext.mwe.SlotEntry.findEClasses(SlotEntry.java:135)
    at org.eclipse.xtext.mwe.SlotEntry.put(SlotEntry.java:91)
    at org.eclipse.xtext.mwe.AbstractReader.addModelElementsToContext(AbstractReader.java:95)
    at org.eclipse.xtext.mwe.Reader.invokeInternal(Reader.java:166)
    at org.eclipse.emf.mwe.core.lib.AbstractWorkflowComponent.invoke(AbstractWorkflowComponent.java:126)
    at org.eclipse.emf.mwe.core.lib.Mwe2Bridge.invoke(Mwe2Bridge.java:34)
    at org.eclipse.emf.mwe.core.lib.AbstractWorkflowComponent.invoke(AbstractWorkflowComponent.java:201)
    at org.eclipse.emf.mwe2.runtime.workflow.AbstractCompositeWorkflowComponent.invoke(AbstractCompositeWorkflowComponent.java:35)
    at org.eclipse.emf.mwe2.runtime.workflow.Workflow.run(Workflow.java:19)
    at org.eclipse.emf.mwe2.launch.runtime.Mwe2Runner.run(Mwe2Runner.java:97)
    ... 5 more

用于创建特定工作流mwe2文件的示例取自Xpand参考手册。

这是来自MANIFEST.MF文件的插件依赖项列表：

Manifest-Version: 1.0
Bundle-ManifestVersion: 2
Bundle-Name: my.neuralnetworks.generator.project
Bundle-SymbolicName: my.neuralnetworks.generator.project; singleton:=true
Bundle-Version: 1.0.0
Require-Bundle: org.eclipse.jdt.core;bundle-version="3.5.0",
 org.eclipse.xtend.profiler;resolution:=optional,
 org.apache.commons.logging,
 org.apache.log4j;resolution:=optional,
 com.ibm.icu;bundle-version="4.0.1",
 org.antlr.runtime;bundle-version="3.0.0",
 org.eclipse.core.runtime;bundle-version="3.5.0",
 org.eclipse.emf.mwe.utils;bundle-version="0.7.0",
 org.eclipse.emf.ecore.xmi;bundle-version="2.5.0",
 org.eclipse.jface.text;bundle-version="3.5.0",
 org.eclipse.xpand;bundle-version="0.7.0",
 org.eclipse.xtend;bundle-version="0.7.0",
 org.eclipse.xtend.typesystem.emf;bundle-version="0.7.0",
 org.eclipse.xtend.backend;bundle-version="1.0.0";resolution:=optional,
 org.eclipse.xtend.middleend.xpand;bundle-version="1.0.0";resolution:=optional,
 org.eclipse.xtend.middleend.xtend;bundle-version="1.0.0";resolution:=optional,
 neuralnetworks;bundle-version="1.0.0",
 org.xtext.example.neuralnetworks;bundle-version="1.0.0",
 org.eclipse.emf.ecore.xmi.source;bundle-version="2.7.0",
 org.eclipse.jface.text.source;bundle-version="3.7.0",
 org.antlr.runtime.source;bundle-version="3.2.0",
 org.antlr.runtime_3.1.b1;bundle-version="3.1.0",
 com.ibm.icu.source;bundle-version="4.4.2",
 org.eclipse.jdt.core.source;bundle-version="3.7.0",
 org.eclipse.emf.mwe2.launch;bundle-version="2.2.0"
Bundle-RequiredExecutionEnvironment: J2SE-1.5
Import-Package: nn

神经网络插件指的是我的图形编辑器的gmf项目，在这里可以找到元模型，而org.xtext.example.neuralnetworks是对应于我的文本编辑器的。

与emf文件相对应的ecore文件中确实有EClass系统。

Answer 1

你的dsl看起来怎么样？它是否包含一个名为EClass的系统？更新:刚刚看到您没有基于Xtext的元模型。因此，如果您想使用Xtext阅读器组件，就必须使用AbstractGenericResourceSupport并注册您的epackage，正如本Xtend2示例http://christiandietrich.wordpress.com/2011/07/29/xtend2-code-generators-with-non-xtext-models/所描述的那样

Answer 2

没有，但是由于您使用的是现有的元模型，而不是派生的元模型，所以您应该在工作流的开头添加以下内容

bean = StandaloneSetup {
    registerGeneratedEPackage = "sample.SamplePackage"
}