following are the operators which are used to create an observable.
| sr.no. | operator & description |
|---|---|
| 1 |
create creates an observable from scratch and allows observer method to call programmatically. |
| 2 |
defer do not create an observable until an observer subscribes. creates a fresh observable for each observer. |
| 3 |
empty/never/throw creates an observable with limited behavior. |
| 4 |
from converts an object/data structure into an observable. |
| 5 |
interval creates an observable emitting integers in sequence with a gap of specified time interval. |
| 6 |
just converts an object/data structure into an observable to emit the same or same type of objects. |
| 7 |
range creates an observable emitting integers in sequence of given range. |
| 8 |
repeat creates an observable emitting integers in sequence repeatedly. |
| 9 |
start creates an observable to emit the return value of a function. |
| 10 |
timer creates an observable to emit a single item after given delay. |
creating operator example
create the following java program using any editor of your choice in, say, c:\> rxjava.
observabletester.java
import io.reactivex.observable;
//using fromarray operator to create an observable
public class observabletester {
public static void main(string[] args) {
string[] letters = {"a", "b", "c", "d", "e", "f", "g"};
final stringbuilder result = new stringbuilder();
observable<string> observable = observable.fromarray(letters);
observable
.map(string::touppercase)
.subscribe( letter -> result.append(letter));
system.out.println(result);
}
}
verify the result
compile the class using javac compiler as follows −
c:\rxjava>javac observabletester.java
now run the observabletester as follows −
c:\rxjava>java observabletester
it should produce the following output −
abcdefg