Designing distributed and parallel applications is an important issue in the context of programming and execution environments. Designing applications as independently and as transparently as possible of the distributed system is not an easy issue. At the same time, improving efficiency of execution is considered to be difficult especially for irregular applications executing on a heterogeneous environment. In ADAJ (Adaptive Distributed Applications in Java), the concept of distributed collections is used as a guide for the methodology of programming Java distributed and parallel applications. Distributed collections encapsulate data parallelism and make use of threads transparent for the user. Asynchronous calls are also proposed in order to achieve task parallelism. The article shows the interest of using distributing collections and asynchronous calls, evaluating both conception and execution of ADAJ applications.