I’m working on a Audio app based on ExoPlayer, I have implemented the MediaSession controls for a NowPlaying bar in Notification Center and Lock Screen. The NowPlaying bar in the Notification Center is working on every phone, but on some Samsung phones (Android 11) the NowPlaying bar is not visible on t…
Tag: stream
Set with Optional
I have this code: I want to replace this code to this: and map this field from myClass to myClass2 How i can do it? Answer Did you mean to use: For mapping I would suggest to read about MapStruct, it is a good tool.
Issues understanding mapMulti
I’m fairly when it comes to Java, and I’ve decided to dig a little into the implementations and uses of the API, especially the Stream API. I’ve made an implementation after thinking I got it right, and it worked. However I realized something that bugged me out. The mapMulti function takes i…
How to collect data to List from Map using java Stream API?
I have map Map<Nominal, Integer> with objects and their counts: And I need to get such a List<Nominal> from it: How can I do this using the Stream API? Answer We can use Collections::nCopies to achieve the desired result: Ideone demo Remark In the demo, I changed the key-type of the Map from Nomin…
How to use stream to filter objects from HashSet that have empty value for certain fields?
I am looking for a way to filter only the Worker objects with a specific first name and empty lastName from the given HashSet. For example I want the code to return the record with firstName == scott and lastName == “”. Answer filter is a non-terminal operation and the stream would be processed on…
Java Collectors Grouping By
I have an input of integers and I would like to sort all even numbers before all odd ones in ascending order and preserve the odds order. I am pretty sure I can achieve that with collectors and/or downstream collectors, but I am not sure how to do it. I would like to know how can I sort the false
Is there a way to reduce multiple methods as one method with Function as methode parameter?
I have several methods that are basically all the same except for one method that is called in these methods. Example: So the only difference is the method getDB(). Since I don’t want to have this method 10 times, I thought of writing this into a method and then controlling it via the input parameters. …
Lambda for comparing two lists of map id fields for missing ids
I have two lists of maps, and each map as an id field. I need to compare these two lists against one another to find missing ids from collectionB (“7777” in the below) I am really looking to learn more about stream() so any help with this would be appreciated. As you can tell I am not really sure …
Sort A List of an Object with other object’s method
In the bellow code, with such classes, how can I sort an ArrayList of Students by the score the got from Courses List? I mean how can I sort a List of a specific class by an attribute of this class which is a child of another class. Answer Your “Student” class is confusing. Based on the name, it s…
How to properly decode and encode characters from JTextArea
I have a program that works on a console, and i want to make a custom console for it. Current command line interface can be started with a method that takes an InputStream and PrintStream as arguments. I have two text areas (JTextArea), one of which i want to use for input and the other one for output. I̵…