When it comes to Android app development, using Java may not be the best way to go. In fact, it might result in more frustration and be more time-consuming than other programming languages. Kotlin, however, seems to have an edge (or a few) over Java.

Here are 5 areas Java struggles with and why Kotlin is a better choice:

  1. Null Safety
  2. Data Classes
  3. Async Calls
  4. Bad SDK APIS
  5. Data Serialization of Activities

Null Safety

In Java, null safety checks are often either used freely or rarely, depending on the developer. However, when they are used less, this can make an application vulnerable. Kotlin has tools that help with null safety. For example, for data that is non-nullable, some kind of value must be assigned to the object when it’s created. This means there will be no null pointer exception or a need for the safety checks.

Data Classes

With data classes in Java, a significant amount of code is needed to establish them. The more code there is, the more errors a system can have. However, Kotlin simplifies this process by automatically lowering the lines of code needed. It has pre-generated codes for the following classes:

  • Getters
  • Setters
  • Equals
  • hashCode

Async Calls

Java struggles to manage network calls and a UI thread simultaneously. It can allow for a callback or implementation of rxJava in order to cancel a request, but that involves extra steps, frustration, and time. Kotlin’s coroutines, on the other hand, individualize threads to enable quick suspension of executions when necessary while reducing the time it takes to cancel a request such as with Java.


In regard to what is known as ‘toasting’, the Android system requires developers to assign a message, its context, and duration to the toast. Java contains a static utility function to do this, which means the code base has to be referenced to and makes the process more rigid. Kotlin once again simplifies this process by pre-generating and inserting the toast based on what is written in a short piece of code.

Data Serialization of Activities

The grouping and assigning of data to that group in order to do things like object sharing across multiple screens is very much possible in the Android system. To do this, a ‘Parcelable’ function is available. Serializing data this way requires code to be written for each section of code to ‘marshal’ or ‘unmarshal’ it. The code must also be changed across the sections when adding or removing data and functions. Once again, Kotlin has can generate this serialization with the code, ‘@Parcelize’.

Java Just Doesn’t Stack Up

Compared to Kotlin, Java primarily falls behind in these categories. Developers do, however, have different experiences with the various software out there. Some may find Java to be more suited to their preferences instead of Kotlin. Nonetheless, both Kotlin and Java each contain unique functions that separates them from the other. Professional backgrounds, personal preferences, and details of specific projects may affect which programming language is better. This is also why the two can be compared in different aspects of the Android app development process.