I have a kotlin data class and I'm trying to call it from Java method.
data class Item (
@PrimaryKey(autoGenerate = true) var var1: Long? ,
@ColumnInfo(name ="var1") var var2: Long){}
From Java , I'm trying to save a list of Item so I need to instance Data class. I don't understand how I can do it.
Instantiating a data class is not different from instatiating a "normal" Kotlin class.
From your Java code, you instantiate it as if it were a Java class:
Item item = new Item(1L, 2L);
Just for reference, a data class is a class that automatically gets the following members (see documentation here):
equals()/hashCode() pair;toString() of the form "MyClass(field1=value1, field2=value2)";componentN() functions corresponding to the properties in their order of declaration; this can be useful for destructuring declarations, such as:
data class Item(val val1: Long, val val2: Long)
fun main(args: Array<String>) {
val item = Item(1L, 2L)
val (first, second) = item
println("$first, $second")
}
This will print: 1, 2
copy() function.
Your data class will be like this :
data class Item (@PrimaryKey(autoGenerate = true) var var1: Long?,
@ColumnInfo(name ="var1") var var2: Long);
From Java you can create create object like this:
Item item=new Item(1L,2L);
long firstValue=item.getVar1();
long secondValue=item.getVar2();
If you want to create instance in kotlin it will be like:
val item=Item(1L,2L);
val firstValue:Long?=item.var1;
val secondValue:Long?=item.var2;
