Short answer: you can't. Ports below 1024 can be opened only by root. As per comment - well, you can, using CAP_NET_BIND_SERVICE, but that approach, applied to java bin will make any java program to be run with this setting, which is undesirable, if not a security risk.
The long answer: you can redirect connections on port 80 to some other port you can open as normal user.
Run as root:
# iptables -t nat -A PREROUTING -p tcp --dport 80 -j REDIRECT --to-port 8080
As loopback devices (like localhost) do not use the prerouting rules, if you need to use localhost, etc., add this rule as well (thanks @Francesco):
# iptables -t nat -I OUTPUT -p tcp -d 127.0.0.1 --dport 80 -j REDIRECT --to-ports 8080
NOTE: The above solution is not well suited for multi-user systems, as any user can open port 8080 (or any other high port you decide to use), thus intercepting the traffic. (Credits to CesarB).
EDIT: as per comment question - to delete the above rule:
# iptables -t nat --line-numbers -n -L
This will output something like:
Chain PREROUTING (policy ACCEPT)
num target prot opt source destination
1 REDIRECT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:8080 redir ports 8088
2 REDIRECT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:80 redir ports 8080
The rule you are interested in is nr. 2, so to delete it:
# iptables -t nat -D PREROUTING 2
Best Answer
You can add a udev rule for your specific device -- to do this, create a file called /etc/udev/010custom.rules (or something similar; just make sure numerically it is the smallest in the directory). The files contents will be:
Replace the bolded keywords with the values for your device from
lsusb
:Bus 005 Device 002: ID 0b05:b700 ASUSTek Computer, Inc. Broadcom Bluetooth 2.1
The first bold field above is IDVENDOR, and the second bold field is PRODUCT.
As for DEVICE, you can define this yourself; it will create a /dev/ node which is a symlink to any device that fits the criteria above (so, if you put foobar as the SYMLINK, udev will create a /dev/foobar which is a symlink to your USB device).
Note: I haven't tried this myself as I don't have any removable USB devices, but it should work. If you have any trouble check the udev documentation for rules.