pekko/akka-docs/src/test/java/jdocs/stream/SilenceSystemOut.java
2021-01-08 17:55:38 +01:00

68 lines
1.5 KiB
Java

/*
* Copyright (C) 2018-2021 Lightbend Inc. <https://www.lightbend.com>
*/
package jdocs.stream;
import akka.actor.ActorRef;
import java.util.function.Predicate;
/**
* Acts as if `System.out.println()` yet swallows all messages. Useful for putting printlines in
* examples yet without polluting the build with them.
*/
public class SilenceSystemOut {
private SilenceSystemOut() {}
public static System get() {
return new System(
new System.Println() {
@Override
public void println(String s) {
// ignore
}
});
}
public static System get(ActorRef probe) {
return new System(
new System.Println() {
@Override
public void println(String s) {
probe.tell(s, ActorRef.noSender());
}
});
}
public static System get(Predicate<String> filter, ActorRef probe) {
return new System(
new System.Println() {
@Override
public void println(String s) {
if (filter.test(s)) probe.tell(s, ActorRef.noSender());
}
});
}
public static class System {
public final Println out;
public System(Println out) {
this.out = out;
}
public abstract static class Println {
public abstract void println(String s);
public void println(Object s) {
println(s.toString());
}
public void printf(String format, Object... args) {
println(String.format(format, args));
}
}
}
}