Java-enabled wireless devices are preferred for various reasons such as enhanced user experience and the support for dynamically downloading applications on demand. The dynamic download capability supports extensibility of the mobile client features and centralizes application maintenance at the server. Also, it enables service providers to customize features for the clients. In this work, we extend this client-server collaboration further by offloading some of the computations (i.e., method execution and dynamic compilation) normally performed by the mobile client to the resource-rich server in order to conserve energy consumed by the client in a wireless Java environment. In the proposed framework, the object serialization feature of Java is used to allow offloading of both method execution and bytecode-to-native code compilation to the server when executing a Java application. Our framework takes into account communication, computation and compilation energies to dynamically decide where to compile and execute a method (locally or remotely) and how to execute it (using interpretation or just-in-time compilation with different levels of optimizations).