Question : Java multi thread singleton

I have following two codes, exisitng codes seems not thread safe. Am I right?

public class Test {

public static Test instance =null;
private Test()
{
}

public synchronized static getInstance(){ <--- add synchronized
if(instance == null)
instance = new Test();

return instance;
}

business logic
}

         
           
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          /**********************Existing codes******************/

public class Test {

     public static Test instance =null;
     private Test()
     {
     }

     public static getInstance(){
        if(instance ==  null)
            instance = new Test();

         return instance;
     }

     business logic
}

           
         

Answer : Java multi thread singleton

try now:

                       
         
           
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             pathToZipFile="C:\temp\test.zip"
extractTo="C:\temp\unzip"

set fs = CreateObject("Scripting.FileSystemObject")
set objLog = fs.CreateTextFile("c:\temp\output.log")
	
Dim oShell
Set oShell = WScript.CreateObject ("WScript.Shell")
oShell.run "cmd /c mkdir " & extractTo
Set oShell = Nothing

Set fso = CreateObject("Scripting.FileSystemObject")
Set folder = fso.getfolder(extractTo)
For each oFile in  folder.Files
	oFile.Delete(True)
Next

set sa = CreateObject("Shell.Application")
set ns = sa.NameSpace(pathToZipFile)
set filesInzip = ns.items
sa.NameSpace(extractTo).CopyHere(filesInzip) 

EnumCSV extractTo

objLog.Close

sub EnumCSV(targetdir)
	Dim fso
	Set fso = CreateObject("Scripting.FileSystemObject")
	Set folder = fso.getfolder(targetdir)
	For Each File in Folder.Files
		If fso.GetExtensionName(File)="csv"Then
			ParseCSV(File)		
		End If
	Next
end sub

sub ParseCSV(csv_file)
	set fs = CreateObject("Scripting.FileSystemObject")
	set objTextFile = fs.OpenTextFile(csv_file)
	dim arrStr,lines,lastdate,lasttime
	lines=0
	
	Do while NOT objTextFile.AtEndOfStream
		arrStr = split(objTextFile.ReadLine,",")
		lines=lines+1
	Loop
	
	lastdate = Replace(arrStr(0),"""","")
	lasttime = Replace(arrStr(1),"""","")
	
	objLog.WriteLine "File: " & csv_file
	objLog.WriteLine "Total Lines: " & lines
	objLog.WriteLine "Last date: " & lastdate
	objLog.WriteLine "Last time: " & lasttime
	objLog.WriteLine
	objTextFile.Close
end sub

           
         