This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
One likely cause of your troubles is that the member "m" in confserver is static, but it's assigned in the constructor. That means each time you create a confserver, any previous value of m is lost, and all confserver objects share the latest one.
If I may: Java programmers universally use capital letters to name classes; for example "ConfServer". Using all-lowercase class names makes your code exceedingly hard to read for an an experienced programmer.