Hello I’m just wondering if there is anyone that could make sense of this java skeleton code table for an enum class. Table: My code currently is this: Is that it? or am I supposed to incorporate the int in some way? Thank you. Answer Every enum includes two properties by default: so, int is already inc…
Tag: enums
Should I keep an enum attribute when it has always the same value as a result of a new inheritance?
I have these classes: Imagine that for some reason, I need to make Car a superclass for two new classes: CombustionCar and ElectricCar. One of the new requierements is that ElectricCar’s brand attribute must be always TESLA value and not any of the other ones values. I’ve thougth some solutions: I…
Why enum constructor “this” and “Enum.this” is different
I have a local enum cache, need in enum constructor return enum instance. but when return ‘this’ , it’s fail, return ‘Enum.this’ , it’s ok. the exception looks like a inner class. because this instance is not finish ? this is my code and exception Answer Here: Notice that t…
How can i can get Strings from Enum after using toString()
I am creating a list from which the user can select from using Vaadin8. I want to get the values from the Enum but the string values with spaces not the Element Names. Here is the list created to select from the Enum elements: And here are 3 lines I tried that did not work: Answer You can add a
How to fix data conversion error: jdbcTemplate.update, writing Enum to H2 database
I use PostgreSql for my main code and H2 for testing, and get different results (test fails). My class with an Enum type field SQL schema is My DAO class In my test method: Everything works with PostgreSql, but test with H2 fails with data conversion error: I think “java.sql.Types.OTHER” that I us…
(Java) Static member accessed via instance reference with enumerators
I just started learning Java. IntelliJ is giving me a warning “Static member accessed via instance reference” on line 4. Is it bad, should I fix it, somehow, or should I just ignore it? Here is my code: and the Dog class: Answer One issue (which causes others) is that you’re hiding the type …
Since when have enum constructors’ default access modifier been private?
How long have enum constructors’ default access modifier been “private”? Since the beginning or did it change in Java 8? If it did, then what was the default access modifier of a constructor declaration with no access modifier? (I’m guessing it is the default(package accessible) like o…
Why can’t enum and record be combined?
Recently I was just creating another enum type. I took advantage of the fact that in Java, an enum is a special type of class (and not a named integer constant, like in C#). I made it with two fields, an all-arg constructor and getters for both fields. This is an example: Then I thought that Java 14’s r…
Java enum with generic attributes
I have been trying to create enum that contains generic attribute, for example: SomeValue1 and SomeValue2 classes implement SomeValue interface. For some reason <T extends SomeValue> is marked with “Unexpected bound” error. If I replace T with ?, there is no error. But it is still puzzling m…
How to iterate through several Enums within a class
I have a class with 70 enums. I would like to iterate through the enums and just output the constants saved in each enum. it looks like this: I found a similar question here. But the question and suggested solutions are for 3 enums only. Is there an easier way than just hardcoding each enum’s name into …