Question

If I create a java Random Access File object against a file. What happens when the file is renamed?

case1. Let’s say, I created a RAF object against test.log. Then I renamed test.log -> test1.log by doing something like

mv test.log test1.log

What happens to my RAF object then in this case?

case2. again, create a RAF object against test.log then:

mv test.log test1.log
touch test.log

in this case, is my object pointing to test.log or test1.log

case3. what if my RAF object is pointing to a log file which will be rotated eventually?

Most importantly, can someone explain to me what happens under the cover? like how the RAF object points/refers to the actual file, how it works when file is renamed or deleted.

Answer 1

===========================

My Own test

===========================

    RandomAccessFile rand = new RandomAccessFile("/tmp/test_log", "rw"); 
    System.out.print("file created"); //======lineA======
    while (true) {
        Thread.sleep(8000);
        System.out.print("finish sleeping");
        int i = (int) rand.length(); //=====lineB=====
        rand.seek(0); // Seek to start point of file
        for (int ct = 0; ct < i; ct++) {
            byte b = rand.readByte(); // read byte from the file
            System.out.print((char) b); // convert byte into char
        }
    }

test case 1:

remove the test_log file after lineA before lineB, it finishes reading the whole file without any problems/Exceptions.

test case 2:

mv /tmp/test_log /tmp/test_log.bk after lineA before lineB, again,it finishes reading the whole file without any problems/Exceptions.

test case 3:

following test case 2, start writing extra lines to /tmp/test_log.bk,

echo "test line1 bla bla" >> /tmp/test_log.bk
echo "test line2 bla bla" >> /tmp/test_log.bk

it reads the whole file now problem, PLUS, it reads the new lines added in test_log.bk as well.