Antipatterns causing memory bloat: A case study

Java is one of the languages that are popular for high abstraction and automatic memory management. As in other object-oriented languages, Java's objects can easily represent a domain model of an application. While it has a positive impact on the design, implementation and maintenance of applications, there are drawbacks as well. One of them is a relatively high memory overhead to manage objects. In this work, we show our experience with searching for this problem in an application that we refactored to use less memory. Although the application was relatively well designed with no memory leaks, it required such a big amount of memory that for large data the application was not usable in reality. We did three relatively simple improvements: we reduced the usage of Java Collections, removed unnecessary object instances, and simplified the domain model, which reduced memory needs up to 88% and made the application better usable and even faster. This work is a case-study reporting results. Moreover, the employed ideas are formulated as a set of antipatterns, which may be used for other applications.