How to avoid this java.io.IOException: No space left on device

Question

If my space is full I get sometimes following exception

java.io.IOException: No space left on device
        at java.io.FileOutputStream.writeBytes(Native Method)
        at java.io.FileOutputStream.write(FileOutputStream.java:282)
        at java.io.ObjectOutputStream$BlockDataOutputStream.drain(ObjectOutputStream.java:1847)
        at java.io.ObjectOutputStream$BlockDataOutputStream.setBlockDataMode(ObjectOutputStream.java:1756)
        at java.io.ObjectOutputStream.<init>(ObjectOutputStream.java:230)

Is there any way in Java to avoid this. I mean do not call write if no space

Answer 1

Java 7 NIO offers the FileStore class to check the available size

Path p = Paths.get("/your/file"); // where you want to write
FileSystem fileSystem = FileSystems.getDefault();
Iterable<FileStore> iterable = fileSystem.getFileStores();

Iterator<FileStore> it = iterable.iterator(); // iterate the FileStore instances
while(it.hasNext()) {
    FileStore fileStore = it.next();
    long sizeAvail = fileStore.getUsableSpace(); // or maybe getUnallocatedSpace()
    if (Files.getFileStore(p).equals(fileStore) { // your Path belongs to this FileStore
        if (sizeAvail > theSizeOfBytesYouWantToWrite) {
            // do your thing
        }
    }
}

Obviously you can still get an IOException as nothing is atomic and other processes might be using the same disk, so keep that in mind and handle the exception accordingly.