FileHandler 中的问题

Question

I'm trying to initialize a FileHandler to write to the given filename, with optional append using the foll syntax:

FileHandler fh = null;
fh = new FileHandler("C:\\Users\\Desktop\\New_folder\\logs\\slate\\TodayLoad-2013-10-24.log",true); 

But I'm getting the exception as:

java.io.IOException: Couldn't get lock for  C:\Users\Desktop\New_folder\logs\slate\TodayLoad-2013-10-24.log
    at java.util.logging.FileHandler.openFiles(Unknown Source)
    at java.util.logging.FileHandler.<init>(Unknown Source)
    at TodayLoad.Load.<init>(SlateSheetLoad.java:173)
    at TodayLoad.Load.SlateSheetLoad.main(SlateSheetLoad.java:423)

How can I solve this issue.

Answer 1

Probably your file is getting accessed by another process. See this post that can help you couldn't get lock for .log file in Java

Answer 2

You will find that you get the error after 100 log files have been written. The root cause is a bug in Java. See, for example,

System Property Controls the java.util.logging.FileHandler's MAX_LOCKS Limit

and

Increase java.util.logging.FileHandler MAX_LOCKS limit

These references also suggest a solution: set the system property "jdk.internal.FileHandlerLogging.maxLocks" well before the code that does the logging. For example, by means of

 // Set maxLocks to 200. The default is 100.
 System.setProperty("jdk.internal.FileHandlerLogging.maxLocks", "200");