29 lines
850 B
Java
29 lines
850 B
Java
// streams/Signal.java
|
|
// (c)2021 MindView LLC: see Copyright.txt
|
|
// We make no guarantees that this code is fit for any purpose.
|
|
// Visit http://OnJava8.com for more book information.
|
|
import java.util.*;
|
|
import java.util.stream.*;
|
|
import java.util.function.*;
|
|
|
|
public class Signal {
|
|
private final String msg;
|
|
public Signal(String msg) { this.msg = msg; }
|
|
public String getMsg() { return msg; }
|
|
@Override public String toString() {
|
|
return "Signal(" + msg + ")";
|
|
}
|
|
static Random rand = new Random(47);
|
|
public static Signal morse() {
|
|
switch(rand.nextInt(4)) {
|
|
case 1: return new Signal("dot");
|
|
case 2: return new Signal("dash");
|
|
default: return null;
|
|
}
|
|
}
|
|
public static Stream<Optional<Signal>> stream() {
|
|
return Stream.generate(Signal::morse)
|
|
.map(signal -> Optional.ofNullable(signal));
|
|
}
|
|
}
|