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RxJava
modules
potatotips #25
@petitviolet
Fringe81 Co,. Ltd.
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About Me
• Hiroki Komurasaki
• @petitviolet
• Fringe81 Co,. Ltd
• Scala Engineer
• ちょっと前までAndroid
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RxJava
使ってますか？
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https://github.com/ReactiveX
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RxJavaに色々と
モジュールがあるので
ちょっと触ってみた
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RxJavaString
https://github.com/ReactiveX/RxJavaString
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private static void log(String msg) {
Log.d(TAG, msg);
}
Observable toSplit = Observable.just("a,b,c");
StringObservable
.split(toSplit, ",")
.subscribe(RxString::log);
Observable toByLine = Observable.just("x\ny\nz\n");
StringObservable
.byLine(toByLine)
.subscribe(RxString::log);
// == StringObservable.split(toByLine, "\n")
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private static void log(String msg) {
Log.d(TAG, msg);
}
Observable toJoin = Observable.just("x", "y", "z");
StringObservable
.join(toJoin, ":")
.subscribe(RxString::log);
Observable toConcat = Observable.just("A", "B", "C");
StringObservable
.stringConcat(toConcat)
.subscribe(RxString::log);
// == StringObservable.join(toConcat, "")
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文字列に関する便利機能
• Observableに対して文字列処理を簡単に
行えるようにするためのショートカット
• InputStreamとかReaderも対象となる
• encode/decodeもある
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RxJavaMath
https://github.com/ReactiveX/RxJavaMath
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Observable src = Observable.just(1, 2, 3, 4, 5);
MathObservable
.averageInteger(src)
.subscribe(RxMath::log);
MathObservable
.min(src)
.subscribe(RxMath::log);
MathObservable
.max(src)
.subscribe(RxMath::log);
MathObservable
.sumInteger(src)
.subscribe(RxMath::log);
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static class User {
private final String name;
private final String email;
User(String name, String email) {
this.name = name;
this.email = email;
}
@Override
public String toString() {
return "User(" + name + ", " + email + ")";
}
}
Observable users = Observable.just(
new User("alice", "[email protected]"),
new User("bob", "[email protected]"),
new User("charley", "[email protected]")
);
MathObservable
.from(users)
.averageInteger(u -> u.email.length())
.subscribe(RxMath::log);
// 5
MathObservable
.from(users)
.max((u1, u2) -> u1.email.length() - u2.email.length())
.subscribe(RxMath::log);
// User(bob, [email protected])
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数値に関する便利機能
• 平均・最大・最小を求めるためのショートカット
• 独自のFunction1やComparatorを使える
• fromでMathObservableに変換出来る
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RxJavaDebug
https://github.com/ReactiveX/RxJavaDebug
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public static void debug(List list) {
SimpleDebugNotificationListener listener = new SimpleDebugNotificationListener();
DebugHook> hook = new DebugHook<>(listener);
RxJavaPlugins.getInstance().registerObservableExecutionHook(hook);
Observable.from(list)
.flatMap(i -> Observable.from(Arrays.asList(i, i * 100)))
.subscribe(integer -> {
Log.d(TAG, "integer -> " + integer);
});
SortedSet> snapshot =
listener.getNotificationsByObservable();
Log.d(TAG, listener.toString(snapshot));
}
List list = Arrays.asList(1, 2, 3, 4, 5);
debug(list);
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public static void debug(List list) {
SimpleDebugNotificationListener listener = new SimpleDebugNotificationListener();
DebugHook> hook = new DebugHook<>(listener);
RxJavaPlugins.getInstance().registerObservableExecutionHook(hook);
Observable.from(list)
.flatMap(i -> Observable.from(Arrays.asList(i, i * 100)))
.subscribe(integer -> {
Log.d(TAG, "integer -> " + integer);
});
SortedSet> snapshot =
listener.getNotificationsByObservable();
Log.d(TAG, listener.toString(snapshot));
}
List list = Arrays.asList(1, 2, 3, 4, 5);
debug(list);
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public static void debug(List list) {
SimpleDebugNotificationListener listener = new SimpleDebugNotificationListener();
DebugHook> hook = new DebugHook<>(listener);
RxJavaPlugins.getInstance().registerObservableExecutionHook(hook);
Observable.from(list)
.flatMap(i -> Observable.from(Arrays.asList(i, i * 100)))
.subscribe(integer -> {
Log.d(TAG, "integer -> " + integer);
});
SortedSet> snapshot =
listener.getNotificationsByObservable();
Log.d(TAG, listener.toString(snapshot));
}
List list = Arrays.asList(1, 2, 3, 4, 5);
debug(list);
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public static void debug(List list) {
SimpleDebugNotificationListener listener = new SimpleDebugNotificationListener();
DebugHook> hook = new DebugHook<>(listener);
RxJavaPlugins.getInstance().registerObservableExecutionHook(hook);
Observable.from(list)
.flatMap(i -> Observable.from(Arrays.asList(i, i * 100)))
.subscribe(integer -> {
Log.d(TAG, "integer -> " + integer);
});
SortedSet> snapshot =
listener.getNotificationsByObservable();
Log.d(TAG, listener.toString(snapshot));
}
List list = Arrays.asList(1, 2, 3, 4, 5);
debug(list);
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integer -> 1
integer -> 100
integer -> 2
integer -> 200
integer -> 3
integer -> 300
integer -> 4
integer -> 400
integer -> 5
integer -> 500
{
"rx.Observable$27@225cfc95": [
{"ns_duration": 17179472, "threadId": 1, "notification": {"observer": "rx.Observable$27@225cfc95", "type": "Subscribe", "source": "rx.Observable@18c8287c", "sourceFunc":
"rx.Observable$2@15773505"}},
{"ns_duration": 127946, "threadId": 1, "notification": {"observer": "rx.Observable$27@225cfc95", "type": "Request", "n": 9223372036854775807, "from":
"rx.internal.operators.OperatorMerge@3cc7495a"}},
{"ns_duration": 190474, "threadId": 1, "notification": {"observer": "rx.Observable$27@225cfc95", "type": "OnNext", "value": "1", "from":
"rx.internal.operators.OperatorMerge@3cc7495a"}},
{"ns_duration": 51643, "threadId": 1, "notification": {"observer": "rx.Observable$27@225cfc95", "type": "OnNext", "value": "100", "from":
"rx.internal.operators.OperatorMerge@3cc7495a"}},
{"ns_duration": 60648, "threadId": 1, "notification": {"observer": "rx.Observable$27@225cfc95", "type": "OnNext", "value": "2", "from":
"rx.internal.operators.OperatorMerge@3cc7495a"}},
{"ns_duration": 31561, "threadId": 1, "notification": {"observer": "rx.Observable$27@225cfc95", "type": "OnNext", "value": "200", "from":
"rx.internal.operators.OperatorMerge@3cc7495a"}},
{"ns_duration": 47015, "threadId": 1, "notification": {"observer": "rx.Observable$27@225cfc95", "type": "OnNext", "value": "3", "from":
"rx.internal.operators.OperatorMerge@3cc7495a"}},
{"ns_duration": 51790, "threadId": 1, "notification": {"observer": "rx.Observable$27@225cfc95", "type": "OnNext", "value": "300", "from":
"rx.internal.operators.OperatorMerge@3cc7495a"}},
{"ns_duration": 451663, "threadId": 1, "notification": {"observer": "rx.Observable$27@225cfc95", "type": "OnNext", "value": "4", "from":
"rx.internal.operators.OperatorMerge@3cc7495a"}},
{"ns_duration": 404011, "threadId": 1, "notification": {"observer": "rx.Observable$27@225cfc95", "type": "OnNext", "value": "400", "from":
"rx.internal.operators.OperatorMerge@3cc7495a"}},
{"ns_duration": 41103, "threadId": 1, "notification": {"observer": "rx.Observable$27@225cfc95", "type": "OnNext", "value": "5", "from":
"rx.internal.operators.OperatorMerge@3cc7495a"}},
{"ns_duration": 72118, "threadId": 1, "notification": {"observer": "rx.Observable$27@225cfc95", "type": "OnNext", "value": "500", "from":
"rx.internal.operators.OperatorMerge@3cc7495a"}},
{"ns_duration": 33840, "threadId": 1, "notification": {"observer": "rx.Observable$27@225cfc95", "type": "OnCompleted", "from": "rx.internal.operators.OperatorMerge@3cc7495a"}},
{"ns_duration": 3058, "threadId": 1, "notification": {"observer": "rx.Observable$27@225cfc95", "type": "Unsubscribe", "from": "rx.internal.operators.OperatorMerge@3cc7495a"}}
],
"rx.internal.operators.OperatorMerge$MergeSubscriber@26cb21aa": [
{"ns_duration": 7064, "threadId": 1, "notification": {"observer": "rx.internal.operators.OperatorMerge$MergeSubscriber@26cb21aa", "type": "OnStart", "to":
"rx.internal.operators.OperatorMerge@3cc7495a"}},
{"ns_duration": 16027011, "threadId": 1, "notification": {"observer": "rx.internal.operators.OperatorMerge$MergeSubscriber@26cb21aa", "type": "Request", "n": 9223372036854775807,
"from": "rx.internal.operators.OperatorMap@2ecfd78b", "to": "rx.internal.operators.OperatorMerge@3cc7495a"}},
{"ns_duration": 13054812, "threadId": 1, "notification": {"observer": "rx.internal.operators.OperatorMerge$MergeSubscriber@26cb21aa", "type": "OnNext", "value":
"rx.Observable@2ad5068", "from": "rx.internal.operators.OperatorMap@2ecfd78b", "to": "rx.internal.operators.OperatorMerge@3cc7495a"}},
{"ns_duration": 21963, "threadId": 1, "notification": {"observer": "rx.internal.operators.OperatorMerge$MergeSubscriber@26cb21aa", "type": "Request", "n": 1, "from":
"rx.internal.operators.OperatorMap@2ecfd78b", "to": "rx.internal.operators.OperatorMerge@3cc7495a"}},
{"ns_duration": 406769, "threadId": 1, "notification": {"observer": "rx.intern
／(^o^)＼
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integer -> 1
integer -> 100
integer -> 2
integer -> 200
integer -> 3
integer -> 300
integer -> 4
integer -> 400
integer -> 5
integer -> 500
subscribeしたところ
Observable.from(list)
.flatMap(i -> Observable.from(Arrays.asList(i, i * 100)))
.subscribe(integer -> {
Log.d(TAG, "integer -> " + integer);
});
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{
"rx.Observable$27@225cfc95": [
{"ns_duration": 17179472, "threadId": 1, "notification": {"observer": "rx.Observable$27@225cfc95", "type": "Subscribe", "source": "rx.Observable@18c8287c",
"sourceFunc": "rx.Observable$2@15773505"}},
{"ns_duration": 127946, "threadId": 1, "notification": {"observer": "rx.Observable$27@225cfc95", "type": "Request", "n": 9223372036854775807, "from":
"rx.internal.operators.OperatorMerge@3cc7495a"}},
{"ns_duration": 190474, "threadId": 1, "notification": {"observer": "rx.Observable$27@225cfc95", "type": "OnNext", "value": "1", "from":
"rx.internal.operators.OperatorMerge@3cc7495a"}},
{"ns_duration": 51643, "threadId": 1, "notification": {"observer": "rx.Observable$27@225cfc95", "type": "OnNext", "value": "100", "from":
"rx.internal.operators.OperatorMerge@3cc7495a"}},
{"ns_duration": 60648, "threadId": 1, "notification": {"observer": "rx.Observable$27@225cfc95", "type": "OnNext", "value": "2", "from":
"rx.internal.operators.OperatorMerge@3cc7495a"}},
{"ns_duration": 31561, "threadId": 1, "notification": {"observer": "rx.Observable$27@225cfc95", "type": "OnNext", "value": "200", "from":
"rx.internal.operators.OperatorMerge@3cc7495a"}},
{"ns_duration": 47015, "threadId": 1, "notification": {"observer": "rx.Observable$27@225cfc95", "type": "OnNext", "value": "3", "from":
"rx.internal.operators.OperatorMerge@3cc7495a"}},
{"ns_duration": 51790, "threadId": 1, "notification": {"observer": "rx.Observable$27@225cfc95", "type": "OnNext", "value": "300", "from":
"rx.internal.operators.OperatorMerge@3cc7495a"}},
{"ns_duration": 451663, "threadId": 1, "notification": {"observer": "rx.Observable$27@225cfc95", "type": "OnNext", "value": "4", "from":
"rx.internal.operators.OperatorMerge@3cc7495a"}},
{"ns_duration": 404011, "threadId": 1, "notification": {"observer": "rx.Observable$27@225cfc95", "type": "OnNext", "value": "400", "from":
"rx.internal.operators.OperatorMerge@3cc7495a"}},
{"ns_duration": 41103, "threadId": 1, "notification": {"observer": "rx.Observable$27@225cfc95", "type": "OnNext", "value": "5", "from":
"rx.internal.operators.OperatorMerge@3cc7495a"}},
{"ns_duration": 72118, "threadId": 1, "notification": {"observer": "rx.Observable$27@225cfc95", "type": "OnNext", "value": "500", "from":
"rx.internal.operators.OperatorMerge@3cc7495a"}},
{"ns_duration": 33840, "threadId": 1, "notification": {"observer": "rx.Observable$27@225cfc95", "type": "OnCompleted", "from":
"rx.internal.operators.OperatorMerge@3cc7495a"}},
{"ns_duration": 3058, "threadId": 1, "notification": {"observer": "rx.Observable$27@225cfc95", "type": "Unsubscribe", "from":
"rx.internal.operators.OperatorMerge@3cc7495a"}}
],
DebugHookによって出されるログ
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{"ns_duration": 17179472,
"threadId": 1,
"notification": {
"observer": “rx.Observable$27@225cfc95",
"type": "Subscribe",
"source": "rx.Observable@18c8287c",
"sourceFunc": “rx.Observable$2@15773505"
}
},
一部抽出・拡大
{"ns_duration": 190474,
"threadId": 1,
"notification": {
"observer": "rx.Observable$27@225cfc95",
"type": "OnNext",
"value": "1",
"from": “rx.internal.operators.OperatorMerge@3cc7495a"
}
},
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いろいろ情報が見れて便利
• Observerに対する以下が分かる
• どのスレッドで
• どのObservableの
• どのonXXXから
• どんな値が渡ってきているか
• 注意点としてはObservableを作る前に設定を行うこと
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RxJavaJoins
https://github.com/ReactiveX/RxJavaJoins
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Observable src_i = Observable.just(1, 2, 3, 4, 5);
Observable src_s = Observable.just("a", "b", "c");
Observable interval = Observable.interval(1, SECONDS);
Plan0 plan =
JoinObservable
.from(src_i)
.and(src_s)
.and(interval)
.then((i, s, l) -> i + ", " + s + ", " + l);
JoinObservable
.when(plan)
.toObservable()
.subscribe(RxJoin::log);
// 1, a, 0
// 2, b, 1
// 3, c, 2
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Observable src_i = Observable.just(1, 2, 3, 4, 5);
Observable src_s = Observable.just("a", "b", "c");
Observable interval = Observable.interval(1, SECONDS);
Observable.zip(
src_i, src_s, interval,
(i, s, l) -> i + ", " + s + ", " + l)
.subscribe(RxJoin::log);
// 1, a, 0
// 2, b, 1
// 3, c, 2
zip使っても書ける
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Observableをまとめるやつ
• zipでいいのでは
• 違いがわからず
• 流れるようなinterfaceで書けるのが利点?
• and, then, when
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まとめ
• RxJavaはモジュール化されている
• 特定の機能を持つモジュール群が存在
• 用途にあったものが実装されているかも
• 今回紹介しなかったのも多数
• AsyncUtilとかParallelなんかも見えた