[HOP-1862] JSON Output: ERROR: Output fieldname that will contain value is empty!

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Cannot Reproduce
• Fix Version/s: Not applicable
• Component/s: Transforms
• Labels: pre-apache
• Assignee: Maximilian Michels
• Reporter: Maximilian Michels
• Created: 04/Oct/20 12:19
• Updated: 16/Jan/21 11:00
• Resolved: 16/Jan/21 11:00

Description

I am trying to create a JSON object with the JSON output. I set it to not write to a file, however, I get this error:

```
ERROR: Output fieldname that will contain value is empty!
```

Details:

```
org.apache.hop.core.exception.HopException:
We failed to initialize at least one transform. Execution can not begin!
2020/05/22 07:46:38 - Hop - Environments enabled
2020/05/22 07:46:38 - Hop - Opening last environment at startup
2020/05/22 07:46:38 - Hop - Audit events found for hop-gui/environment : 5
2020/05/22 07:46:38 - Hop - Found last environment at startup: hop-beam-examples-dev
2020/05/22 07:46:38 - Hop - Setting environment : 'hop-beam-examples-dev'
2020/05/22 07:48:43 - js-problem - Executing this pipeline using the Local Pipeline Engine with run configuration 'local'
2020/05/22 07:48:43 - js-problem - Execution started for pipeline [js-problem]
2020/05/22 07:48:43 - JSON output.0 - ERROR: Output fieldname that will contain value is empty!
2020/05/22 07:48:43 - JSON output.0 - ERROR: Error initializing transform [JSON output]
2020/05/22 07:48:43 - js-problem - ERROR: Transform [JSON output.0] failed to initialize!

at org.apache.hop.pipeline.Pipeline.prepareExecution(Pipeline.java:1152)
at org.apache.hop.pipeline.engines.local.LocalPipelineEngine.prepareExecution(LocalPipelineEngine.java:88)
at org.apache.hop.ui.hopgui.file.pipeline.HopGuiPipelineGraph.debug(HopGuiPipelineGraph.java:3774)
at org.apache.hop.ui.hopgui.file.pipeline.delegates.HopGuiPipelineRunDelegate.executePipeline(HopGuiPipelineRunDelegate.java:240)
at org.apache.hop.ui.hopgui.file.pipeline.HopGuiPipelineGraph.preview(HopGuiPipelineGraph.java:3155)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.apache.hop.core.gui.plugin.action.GuiActionLambdaBuilder.lambda$createLambda$0(GuiActionLambdaBuilder.java:93)
at org.apache.hop.ui.hopgui.context.GuiContextUtil.handleActionSelection(GuiContextUtil.java:125)
at org.apache.hop.ui.hopgui.file.pipeline.HopGuiPipelineGraph.lambda$mouseUp$0(HopGuiPipelineGraph.java:1188)
at org.eclipse.swt.widgets.Display.runTimers(Display.java:4361)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3782)
at org.apache.hop.ui.hopgui.HopGui.open(HopGui.java:354)
at org.apache.hop.ui.hopgui.HopGui.main(HopGui.java:298)
```

When I try to save the pipeline, I get also this error now:

```
org.apache.hop.core.exception.HopException:
Error saving pipeline to file '/Users/diethardsteiner/git/hop-beam-examples/pipelines-and-workflows/transform_event_data_to_json.hpl'
at org.apache.hop.ui.hopgui.HopGui.main (HopGui.java:298)
at org.apache.hop.ui.hopgui.HopGui.open (HopGui.java:354)
at org.eclipse.swt.widgets.Display.readAndDispatch (Display.java:3791)
at org.eclipse.swt.widgets.Display.runDeferredEvents (Display.java:4174)
at org.eclipse.swt.widgets.Widget.notifyListeners (Widget.java:1324)
at org.eclipse.swt.widgets.Widget.sendEvent (Widget.java:1520)
at org.eclipse.swt.widgets.Widget.sendEvent (Widget.java:1535)
at org.eclipse.swt.widgets.Widget.sendEvent (Widget.java:1512)
at org.eclipse.swt.widgets.Display.sendEvent (Display.java:4387)
at org.eclipse.swt.widgets.EventTable.sendEvent (EventTable.java:89)
at org.apache.hop.ui.core.gui.GuiMenuWidgets.lambda$addMenuWidgets$0 (GuiMenuWidgets.java:124)
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.apache.hop.ui.hopgui.HopGui.menuFileSave (HopGui.java:491)
at org.apache.hop.ui.hopgui.delegates.HopGuiFileDelegate.fileSave (HopGuiFileDelegate.java:137)
at org.apache.hop.ui.hopgui.file.pipeline.HopGuiPipelineGraph.save (HopGuiPipelineGraph.java:3310)
at org.apache.hop.pipeline.PipelineMeta.getXml (PipelineMeta.java:1838)
at org.apache.hop.pipeline.PipelineMeta.getXml (PipelineMeta.java:1933)
at org.apache.hop.pipeline.transform.TransformMeta.getXml (TransformMeta.java:166)
at org.apache.hop.pipeline.transform.TransformMeta.getXml (TransformMeta.java:188)
at org.apache.hop.pipeline.transforms.jsonoutput.JsonOutputMeta.getXml (JsonOutputMeta.java:367)

at org.apache.hop.ui.hopgui.file.pipeline.HopGuiPipelineGraph.save(HopGuiPipelineGraph.java:3325)
at org.apache.hop.ui.hopgui.delegates.HopGuiFileDelegate.fileSave(HopGuiFileDelegate.java:137)
at org.apache.hop.ui.hopgui.HopGui.menuFileSave(HopGui.java:491)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.apache.hop.ui.core.gui.GuiMenuWidgets.lambda$addMenuWidgets$0(GuiMenuWidgets.java:124)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:89)
at org.eclipse.swt.widgets.Display.sendEvent(Display.java:4387)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1512)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1535)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1520)
at org.eclipse.swt.widgets.Widget.notifyListeners(Widget.java:1324)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4174)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3791)
at org.apache.hop.ui.hopgui.HopGui.open(HopGui.java:354)
at org.apache.hop.ui.hopgui.HopGui.main(HopGui.java:298)
Caused by: java.lang.NullPointerException
at org.apache.hop.pipeline.transforms.jsonoutput.JsonOutputMeta.getXml(JsonOutputMeta.java:367)
at org.apache.hop.pipeline.transform.TransformMeta.getXml(TransformMeta.java:188)
at org.apache.hop.pipeline.transform.TransformMeta.getXml(TransformMeta.java:166)
at org.apache.hop.pipeline.PipelineMeta.getXml(PipelineMeta.java:1933)
at org.apache.hop.pipeline.PipelineMeta.getXml(PipelineMeta.java:1838)
at org.apache.hop.ui.hopgui.file.pipeline.HopGuiPipelineGraph.save(HopGuiPipelineGraph.java:3310)
... 17 more
```