Logo Questions Linux Laravel Mysql Ubuntu Git Menu
 

FindBugs - "may fail to close stream" when using ObjectOutputStream

I have this piece of code, which is to write an Ojbect to a byte array stream:

     static byte[] toBytes(MyTokens tokens) throws IOException {
        ByteArrayOutputStream out = null;
        ObjectOutput s = null;
        try {
            out = new ByteArrayOutputStream();
            try {
                s = new ObjectOutputStream(out);
                s.writeObject(tokens);
            } finally {
                try {
                    s.close();
                } catch (Exception e) {
                    throw new CSBRuntimeException(e);
                }             
            }
        } catch (Exception e) {
            throw new CSBRuntimeException(e);
        } finally {
            IOUtils.closeQuietly(out);
        }
        return out.toByteArray();
    }

However, FindBugs keeps complaining about line:

s = new ObjectOutputStream(out);

that "may fail to close stream" - BAD_PRACTICE - OS_OPEN_STREAM. Can somebody help?

like image 213
Eugene Avatar asked Jan 21 '13 07:01

Eugene


2 Answers

I think FindBugs does not undestand that IOUtils.closeQuietly(out) closes out.

Anyway it is enough to close ObjectOutputStream and it will close underlying ByteArrayOutputStream. This is ObjectOutputStream.close implementation

public void close() throws IOException {
    flush();
    clear();
    bout.close();
}

so you can simplify your code

    ByteArrayOutputStream out = new ByteArrayOutputStream();
    ObjectOutputStream s = new ObjectOutputStream(out);
    try {
        s.writeObject(1);
    } finally {
        IOUtils.closeQuietly(s);
    }

or if you are in Java 7

    ByteArrayOutputStream out = new ByteArrayOutputStream();
    try (ObjectOutputStream s = new ObjectOutputStream(out)) {
        s.writeObject(1);
    }
like image 194
Evgeniy Dorofeev Avatar answered Nov 14 '22 13:11

Evgeniy Dorofeev


It means that s.close() will try to close underlying stream, but it may fail to do it. So to be sure you should close it on your own also. Try to add out.close() and see if warning disappears.

like image 35
partlov Avatar answered Nov 14 '22 15:11

partlov