Do you need to explicity close a Java KeyStore input stream?

Question

When reading in a KeyStore using a FileInputStream as follows, does one need to explicitly close the input-steam to stop system resources being wasted ?

FileInputStream fin = new FileInputStream("keystore.jks");
KeyStore keystore = KeyStore.getInstance("JKS");
keystore.load(fin, password);

//  Is this line needed ??
fin.close();

Is this FileInputStream closed automatically by the load() method or is explicit manually intervention required?

Answer 1

Is this FileInputStream closed automatically by the load() method or is explicit manually intervention required?

yes it required to close to over come unnecessary leaks.

Checkout example given in java doc of KeyStore http://docs.oracle.com/javase/7/docs/api/java/security/KeyStore.html

Answer 2

Yes, try this test

    FileInputStream fin = new FileInputStream("keystore.jks") {
        public void close() throws java.io.IOException {
            System.out.println("close");
        }
    };
    KeyStore keystore = KeyStore.getInstance("JKS");
    keystore.load(fin, "changeit".toCharArray());

and you will see that close() is not called

Answer 3

You should definitly use org.apache.commons.io.IOUtils.closequietly when dealing with streams and APIs you are not sure about