UDP listener in Java

We need a small piece of java software/server written. The server will be used to listen for incoming UDP-packets. Based on information in these packets and who they are sent from (IP address), the server will update necessary information in an existing MySQL database. We also need some test software so we can generate a burst of udp packets to verify the performance of the server software. ## Deliverables **Background** We have software system called GS. It runs in a Java servlet container (typically Tomcat). This limits what it can do outside http-transfers since the container is only meant to handle web/http based requests. The system's core purpose is to coordinate and communicate with a widely distributed network of mixed hardware devices. It needs to be able to not only actively communicate over http, but also to passively listen for any type of incoming data over any type of protocol. In order to freely and flexibly handle any incoming communication we need to move out of the servlet container, we need to build our own communication server. This server will not replace the Java servlet container in any way, it is intended to expand the communication capabilities of the system beyond the http-protocol. **Functionality** The initial implementation of the server will be used to listen for incoming UDP-packets. Based on information in these packets and who they are sent from, the server will update necessary information in the core database (i.e. the same database that the Java servlet container running GS uses). **Implementation requirements** The server should be configured using a standard .properties-file. The location/name of this file should be specified at startup using a command line parameter. The configuration file should contain all needed info like listening ports, database connection info, etc. The server should listen on a configurable port for UDP-packets. It should extract the message text and the sender ip/port from the packet. There will potentially be lots of packets arriving in bursts so the listener must have good performance and use non-blocking i/o. Based on the extracted info the server should query the database and find the Device. The Device has a column comm_last_success which should be updated with the current timestamp. The server should use log4j and log incoming packets and the resulting actions and errors. The server should be able to shutdown gracefully, making sure to close all database connections etc. This could be done by listening on a specific port for a specific message.