org.netbeans.api.db.explorer.DatabaseException: org.netbeans.api.db.explorer.DatabaseException: unable to connect to server
        at org.netbeans.modules.db.explorer.infos.RootNodeInfo.initChildren(RootNodeInfo.java:170)
        at org.netbeans.modules.db.explorer.infos.DatabaseNodeInfo.getChildren(DatabaseNodeInfo.java:697)
        at org.netbeans.modules.db.explorer.infos.DatabaseNodeInfo.refreshChildren(DatabaseNodeInfo.java:357)
        at org.netbeans.modules.db.explorer.infos.RootNodeInfo.refreshChildren(RootNodeInfo.java:305)
        at org.netbeans.modules.db.explorer.infos.RootNodeInfo.stateChanged(RootNodeInfo.java:297)
        at org.netbeans.modules.db.explorer.infos.RootNodeInfo$1.connectionsChanged(RootNodeInfo.java:103)
        at org.netbeans.modules.db.explorer.ConnectionList.fireListeners(ConnectionList.java:197)
        at org.netbeans.modules.db.explorer.ConnectionList.access$000(ConnectionList.java:71)
        at org.netbeans.modules.db.explorer.ConnectionList$1.resultChanged(ConnectionList.java:104)
        at org.openide.util.lookup.AbstractLookup.notifyListeners(AbstractLookup.java:518)
        at org.openide.util.lookup.AbstractLookup$1Notify.run(AbstractLookup.java:308)
        at org.openide.loaders.FolderLookup$Dispatch.run(FolderLookup.java:304)
        at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:572)
        at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:997)
org.netbeans.api.db.explorer.DatabaseException: unable to connect to server
        at org.netbeans.modules.db.explorer.infos.ConnectionNodeInfo.connect(ConnectionNodeInfo.java:395)
        at org.netbeans.modules.db.explorer.infos.RootNodeInfo.createConnectionNodeInfo(RootNodeInfo.java:227)
        at org.netbeans.modules.db.explorer.infos.RootNodeInfo.initChildren(RootNodeInfo.java:154)
        at org.netbeans.modules.db.explorer.infos.DatabaseNodeInfo.getChildren(DatabaseNodeInfo.java:697)
        at org.netbeans.modules.db.explorer.infos.DatabaseNodeInfo.refreshChildren(DatabaseNodeInfo.java:357)
        at org.netbeans.modules.db.explorer.infos.RootNodeInfo.refreshChildren(RootNodeInfo.java:305)
        at org.netbeans.modules.db.explorer.infos.RootNodeInfo.stateChanged(RootNodeInfo.java:297)
        at org.netbeans.modules.db.explorer.infos.RootNodeInfo$1.connectionsChanged(RootNodeInfo.java:103)
        at org.netbeans.modules.db.explorer.ConnectionList.fireListeners(ConnectionList.java:197)
        at org.netbeans.modules.db.explorer.ConnectionList.access$000(ConnectionList.java:71)
        at org.netbeans.modules.db.explorer.ConnectionList$1.resultChanged(ConnectionList.java:104)
        at org.openide.util.lookup.AbstractLookup.notifyListeners(AbstractLookup.java:518)
        at org.openide.util.lookup.AbstractLookup$1Notify.run(AbstractLookup.java:308)
        at org.openide.loaders.FolderLookup$Dispatch.run(FolderLookup.java:304)
        at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:572)
        at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:997)