In accordance with an embodiment, described herein is a system and method for automatic porting of software applications into a cloud computing environment (cloud environment, cloud). A cloud service enables software developers to deploy user applications to run within the cloud environment. When a user application is deployed to the environment, a deployment logic determines those aspects of the application, such as certain service usages, that may be incompatible with features provided by the environment, or that should use a particular cloud service, and automatically ports the application, including the use of one or more handlers or extensions, for use within the environment. For example, a user application may have been originally developed to use JavaMail, which presents a security risk in a cloud environment. To minimize such risk, the application can instead be ported to use, for example, a REST-based e-mail service supported by the cloud environment.