你能看出不合理的地方吗（内存方面）

// BAD CODE - DO NOT EMULATE
public class LeakyChecksum {
    private byte[] byteArray;
   
    public synchronized int getFileChecksum(String fileName) {
        int len = getFileSize(fileName);
        if (byteArray == null || byteArray.length < len)
            byteArray = new byte[len];
        readFileContents(fileName, byteArray);
        // calculate checksum and return it
    }
}



public class LeakyStack {
    private Object[] elements = new Object[MAX_ELEMENTS];
    private int size = 0;
   
    public void push(Object o) { elements[size++] = o; }
   
    public Object pop() {
        if (size == 0)
            throw new EmptyStackException();
        else {
            Object result = elements[--size];
            // elements[size+1] = null;
            return result;
        }
    }
}