Are you in Java and want to travel around the island? Then take the train or in the Behasa 'Kereta Api', because Java has a very good train network. And it is a sustainable way of traveling. Partly set up by the Dutch when Indonesia was a Dutch Colony. The first track that was laid at the time was the train connection between Bativia (now Jakarta) and Buitenzorg (now Bogor).
Other advantages of the train are that you do not suffer from traffic jams and in the meantime you can enjoy the most beautiful Javanese landscapes. If you take the train from West to East Java, you will go on a journey with beautiful views where you see the real Javanese life as you pass villages and cities.
In the Netherlands we have a 1st and 2nd class, but in Indonesia they work with three different classes: Economy, Business and Executive class. If you compare it with the train in the Netherlands, the Executive class corresponds most closely to our 2nd class.
All three classes are fine, but be aware that the Economy class does not have air conditioning. In addition, many Indonesians use this class, which means that the coupes can be overcrowded. When I took the train from Jakarta to Bandung, my Economy coupe was almost empty, so I had a great experience with this class.
If you opt for the Executive class, you will also have comfortable seats and charging points for your phone in addition to good air conditioning. If you are going to cover a long stretch by train, my advice is to book the Business class or the Executive class.
If you want a seat in Business or Executive class, I advise you to order the ticket in advance. Especially in the high season, the train is a favorite with both tourists and Indonesians themselves. Business class tickets are the most popular during this period. To avoid sitting in a crowded Economy class coupe, it is better to order your ticket in advance. A good and nice site where you can do this is Tiket.com. This site is also available in English. The amounts mentioned are still in rupiah.
Tiket also has an app that can also be used in English. If you buy a ticket via the app, it is also directly in your app.
If you then continue your journey by plane to another Indonesian island, you can also book airline tickets via this app.