Question

I am using a StringBuilder to create a File object, but am also using it to see if the directory the file is located inside of exists:

StringBuilder sbFile = new StringBuilder();
sbFile.append("/home/logs/");

File oFile = new File(sbFile.toString());

if(!oFile.exists())
    oFile.mkdir();

sbFile.append("MyLogFile.log");

oFile = new File(sbFile.toString());

But I am worried that reusing the same oFile reference on two different “versions” of the string builder (/home/logs/ vs /home/logs/MyLogFile.log) will create a memory leak. If so, how should I write this differently?

Answer 1

There is no memory leak. The instance of File created for the first time, will be garbage-collected by JVM when it is no longer used.

The other thing is that you don’t really need to use StringBuilder. File class has a constructor that takes a parent and a filename. Your example could look like this:

File parent = new File("/home/logs/");
if(!parent.exists())
    parent.mkdir();

File file = new File(parent, "MyLogFile.log");
// TODO: do something with file...

Also, you may be interested in how garbage collection works in Java.