【kettle】pdi/data-integration 打开ktr文件报错“Unable to load step info from XML“

一、报错内容：

Unable to load step info from XML step nodeorg.pentaho.di.core.exception.KettleXMLException: 
Unable to load step info from XMLat org.pentaho.commons.launcher.Launcher.main (Launcher.java:92)at java.lang.reflect.Method.invoke (Method.java:498)at sun.reflect.DelegatingMethodAccessorImpl.invoke (DelegatingMethodAccessorImpl.java:43)at sun.reflect.NativeMethodAccessorImpl.invoke (NativeMethodAccessorImpl.java:62)at sun.reflect.NativeMethodAccessorImpl.invoke0 (NativeMethodAccessorImpl.java:-2)at org.pentaho.di.ui.spoon.Spoon.main (Spoon.java:707)at org.pentaho.di.ui.spoon.Spoon.start (Spoon.java:9179)at org.pentaho.di.ui.spoon.Spoon.waitForDispose (Spoon.java:7817)at org.pentaho.di.ui.spoon.Spoon.readAndDispatch (Spoon.java:1381)at org.eclipse.swt.widgets.Display.readAndDispatch (null:-1)at org.eclipse.swt.widgets.Display.runDeferredEvents (null:-1)at org.eclipse.swt.widgets.Widget.sendEvent (null:-1)at org.eclipse.swt.widgets.Display.sendEvent (null:-1)at org.eclipse.swt.widgets.EventTable.sendEvent (null:-1)at org.eclipse.jface.action.ActionContributionItem$5.handleEvent (ActionContributionItem.java:402)at org.eclipse.jface.action.ActionContributionItem.access$2 (ActionContributionItem.java:490)at org.eclipse.jface.action.ActionContributionItem.handleWidgetSelection (ActionContributionItem.java:545)at org.eclipse.jface.action.Action.runWithEvent (Action.java:498)at org.pentaho.ui.xul.jface.tags.JfaceMenuitem$1.run (JfaceMenuitem.java:106)at org.pentaho.ui.xul.jface.tags.JfaceMenuitem.access$100 (JfaceMenuitem.java:43)at org.pentaho.ui.xul.impl.AbstractXulComponent.invoke (AbstractXulComponent.java:141)at org.pentaho.ui.xul.impl.AbstractXulComponent.invoke (AbstractXulComponent.java:157)at org.pentaho.ui.xul.impl.AbstractXulDomContainer.invoke (AbstractXulDomContainer.java:313)at java.lang.reflect.Method.invoke (Method.java:498)at sun.reflect.DelegatingMethodAccessorImpl.invoke (DelegatingMethodAccessorImpl.java:43)at sun.reflect.NativeMethodAccessorImpl.invoke (NativeMethodAccessorImpl.java:62)at sun.reflect.NativeMethodAccessorImpl.invoke0 (NativeMethodAccessorImpl.java:-2)at org.pentaho.di.ui.spoon.Spoon.openFile (Spoon.java:4252)at org.pentaho.di.ui.spoon.Spoon.openFile (Spoon.java:4315)at org.pentaho.di.ui.spoon.Spoon.openFile (Spoon.java:4637)at org.pentaho.di.ui.spoon.TransFileListener.open (TransFileListener.java:61)at org.pentaho.di.trans.TransMeta.loadXML (TransMeta.java:3075)at org.pentaho.di.trans.step.StepMeta.<init> (StepMeta.java:321)at org.pentaho.di.trans.steps.fileinput.text.TextFileInputMeta.loadXML (TextFileInputMeta.java:328)at org.pentaho.big.data.kettle.plugins.hdfs.trans.HadoopFileInputMeta.loadSource (HadoopFileInputMeta.java:108)at org.pentaho.big.data.kettle.plugins.hdfs.trans.HadoopFileInputMeta.loadUrl (HadoopFileInputMeta.java:145)at org.pentaho.di.core.vfs.KettleVFS.getFileObject (KettleVFS.java:105)at org.pentaho.di.core.vfs.KettleVFS.getFileObject (KettleVFS.java:109)at org.pentaho.di.core.vfs.KettleVFS.getFileObject (KettleVFS.java:152)at org.apache.commons.vfs2.impl.DefaultFileSystemManager.resolveFile (DefaultFileSystemManager.java:648)at org.pentaho.di.core.vfs.ConcurrentFileSystemManager.resolveFile (ConcurrentFileSystemManager.java:91)at org.apache.commons.vfs2.impl.DefaultFileSystemManager.resolveFile (DefaultFileSystemManager.java:711)at org.apache.commons.vfs2.provider.AbstractOriginatingFileProvider.findFile (AbstractOriginatingFileProvider.java:55)at org.apache.commons.vfs2.provider.AbstractOriginatingFileProvider.findFile (AbstractOriginatingFileProvider.java:71)at org.apache.commons.vfs2.provider.AbstractOriginatingFileProvider.getFileSystem (AbstractOriginatingFileProvider.java:93)at org.apache.commons.vfs2.provider.AbstractFileProvider.addFileSystem (AbstractFileProvider.java:96)at org.apache.commons.vfs2.provider.AbstractVfsContainer.addComponent (AbstractVfsContainer.java:49)at org.apache.commons.vfs2.provider.AbstractFileSystem.init (AbstractFileSystem.java:115)at org.pentaho.big.data.impl.vfs.hdfs.HDFSFileSystem.addCapabilities (HDFSFileSystem.java:52)

二、日志解读

kettle日志有个特点，最后被调用的栈\代码在最下边，这和java是相反的。所以从下往上看报错就对了。

（1）此处报空指针。HDFSFileSystem.addCapabilities 可能是hadoop fileSystem（以下简称fs）没有取到。
（2）在之前果然有取fs的代码 AbstractOriginatingFileProvider.getFileSystem
所以可以推断kettle在读取ktr或kjb时候就会尝试获取fs，但是后面代码缺少校验，所以包空指针错误。

所以直接文本编辑器打开ktr文件，可以看到类似下边的内容：
在这里插入图片描述