[ZOOKEEPER-4194] ZooInspector throws NullPointerExceptions to console when node data is null

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.7.0
• Fix Version/s: 3.6.3, 3.8.0, 3.7.1
• Component/s: contrib
• Labels: pull-request-available
• Assignee: Unassigned
• Reporter: Brent
• Created: 27/Jan/21 05:19
• Updated: 27/Mar/21 18:01
• Resolved: 27/Mar/21 18:01

Description

In certain scenarios when investigating empty nodes, ZooInspector encounters NullPointerExceptions such as (from testing an Apache Helix cluster):

ERROR [SwingWorker-pool-1-thread-3] (ZooInspectorManagerImpl.java:255) - Error occurred getting data for node: /BrentTest/EXTERNALVIEWERROR [SwingWorker-pool-1-thread-3] (ZooInspectorManagerImpl.java:255) - Error occurred getting data for node: /BrentTest/EXTERNALVIEWjava.lang.NullPointerException at java.lang.String.<init>(String.java:566) at org.apache.zookeeper.inspector.encryption.BasicDataEncryptionManager.decryptData(BasicDataEncryptionManager.java:33) at org.apache.zookeeper.inspector.manager.ZooInspectorManagerImpl.getData(ZooInspectorManagerImpl.java:251) at org.apache.zookeeper.inspector.gui.nodeviewer.NodeViewerData$2.doInBackground(NodeViewerData.java:105) at org.apache.zookeeper.inspector.gui.nodeviewer.NodeViewerData$2.doInBackground(NodeViewerData.java:100) at javax.swing.SwingWorker$1.call(SwingWorker.java:295) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at javax.swing.SwingWorker.run(SwingWorker.java:334) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at java.lang.Thread.run(Thread.java:748)

By default, ZooInspector uses org.apache.zookeeper.inspector.encryption.BasicDataEncryptionManager to decrypt node data using this code:

public String decryptData(byte[] encrypted) throws Exception { 
    return new String(encrypted);
}

But "encrypted" can get passed as "null" which causes the issue.  It seems like this is probably a pretty easy fix (this code seems to do it):

public String decryptData(byte[] encrypted) throws Exception { 
    return encrypted != null ? new String(encrypted) : "";
}

 I can put this on my list of PRs to submit if that seems reasonable.

Issue Links

• links to: GitHub Pull Request #1601