What is the maximum name length of the TempFile in java and MaximumFilesize is depending
on the machine where we mention the temp directory to be created or some other java based?
When to call the deleteOnExit() method--- but what is the use of this method because it gets called when the JVM comes down.But in Production based servers will run 24*7.So file will be created continuously and it will be problem for the server where we create file because of the memory.
To autoclean temp-files older (modified) than XX seconds...
import java.io.File;
import java.io.IOException;
import java.util.HashSet;
public class FileAutoCleaner {
final static FileAutoCleaner singleton = new FileAutoCleaner();
final HashSet<File> bag = new HashSet<File>();
public static FileAutoCleaner getInstance() {
return singleton;
}
// This create the temp file and add to bag for checking
public synchronized File createTempFile(String prefix, String suffix) throws IOException {
File tmp = File.createTempFile(prefix, suffix);
tmp.deleteOnExit();
bag.add(tmp);
return tmp;
}
// Periodically call this function to clean old files
public synchronized void cleanOldFiles(final int secondsOld) {
long now = (System.currentTimeMillis() / 1000);
for (File f : bag) {
long expired = (f.lastModified() / 1000) + secondsOld;
if (now >= expired) {
System.out.println("Deleted file=" + f.getAbsolutePath());
f.delete();
bag.remove(f);
}
}
}
public static void main(String[] args) throws Exception {
FileAutoCleaner fac = FileAutoCleaner.getInstance();
System.out.println(System.currentTimeMillis() / 1000);
fac.createTempFile("deleteme", "tmp");
for (int i = 0; i < 5; i++) {
System.out.println(System.currentTimeMillis() / 1000);
// delete if older than 2 seconds
fac.cleanOldFiles(2);
Thread.sleep(1000);
}
}
}
Iterator and posted as answer to another question here: stackoverflow.com/a/61509973/10166336What is the maximum name length of the TempFile in java and MaximumFilesize is depenting on the machine where we mention the temp directory to be created or some other java based?
1775 static File generateFile(String prefix, String suffix, File dir) {
1776 long n = random.nextLong();
1777 if (n == Long.MIN_VALUE) {
1778 n = 0; // corner case
1779 } else {
1780 n = Math.abs(n);
1781 }
1782 return new File(dir, prefix + Long.toString(n) + suffix);
1783 }
so the file name could be any random long with prefix suffix
When to call the deleteOnExit() method--- but what is the use of this method because it gets called when the JVM comes down.But in Production based servers will run 24*7
There are some file thats needs to be created for application life,
For example when you launch eclipse you will see .lock file created to lock the work space it will get deleted when your eclipse exists
delete() methodString tmpDir = System.getProperty("java.io.tmpdir");
File file=new File(tmpDir+"\"+fileName+".tmp");
