In this paper we present JNetMan, a new Java framework for rapid development of network management solutions based on SNMP (Simple Network Management Protocol). Developed as an open-source project, JNetMan aims at easing network management by offering a set of powerful primitives to directly interact with SNMP-capable devices using a high-level abstraction of the network topology and a set of high-level management libraries (e.g. to obtain the current bit-rate of a link, modify the parameters of the routing protocol, etc.). The result is a reusable and highly configurable software platform that can be used by users to easily develop specific applications for the management of telecommunications networks operated with legacy management protocols, thus allowing fast experimental validation of new solutions. Moreover, thanks to its highly modular structure, JNetMan can be further developed and extended by adding new modules for the management of networks aspects which are not still supported. The implementation of a management application to optimize the network energy consumption is briefly illustrated to clearly point out the potentialities of the platform.