#36 rxjava: 데이터 변환 - map, flatmap

RxJava/practice/src/main/java/org/example/ex10/ObservableFlatMapEx01.java

@@ -0,0 +1,16 @@
+package org.example.ex10;
+
+import io.reactivex.rxjava3.core.Observable;
+import org.example.utils.LogType;
+import org.example.utils.Logger;
+
+/**
+ * FlapMap을 이용한 1 대 다 mapping 예제
+ */
+public class ObservableFlatMapEx01 {
+    public static void main(String[] args) {
+        Observable.just("Hello")
+                .flatMap(hello -> Observable.just("자바", "파이썬", "안드로이드").map(lang -> hello + ", " + lang))
+                .subscribe(data -> Logger.log(LogType.ON_NEXT, data));
+    }
+}

RxJava/practice/src/main/java/org/example/ex10/ObservableFlatMapEx02.java

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+package org.example.ex10;
+
+import io.reactivex.rxjava3.core.Observable;
+import org.example.utils.LogType;
+import org.example.utils.Logger;
+
+/**
+ * flapMap을 이용한 구구단의 2단 출력 예제
+ */
+public class ObservableFlatMapEx02 {
+    public static void main(String[] args){
+        Observable.range(2, 1)
+                .flatMap(
+                        num -> Observable.range(1, 9)
+                                         .map(row -> num + " * " + row + " = " + num * row)
+                )
+                .subscribe(data -> Logger.log(LogType.ON_NEXT, data));
+    }
+}

RxJava/practice/src/main/java/org/example/ex10/ObservableFlatMapEx03.java

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+package org.example.ex10;
+
+import io.reactivex.rxjava3.core.Observable;
+import org.example.utils.LogType;
+import org.example.utils.Logger;
+
+/**
+ * FlatMap 두번째 유형을 이용한 구구단의 2단 출력 예제
+ */
+public class ObservableFlatMapEx03 {
+    public static void main(String[] args) {
+        Observable.range(2, 1)
+                .flatMap(
+                        data -> Observable.range(1, 9),
+                        (sourceData, transformedData) ->
+                                sourceData + " * " + transformedData + " = " + sourceData * transformedData
+                )
+                .subscribe(data -> Logger.log(LogType.ON_NEXT, data));
+
+    }
+}

RxJava/practice/src/main/java/org/example/ex10/ObservableMapEx01.java

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+package org.example.ex10;
+
+import io.reactivex.rxjava3.core.Observable;
+import org.example.utils.LogType;
+import org.example.utils.Logger;
+
+import java.util.Arrays;
+import java.util.List;
+
+/**
+ * Observable이 통지한 항목에 함수를 적용하여 통지된 값을 변환시킨다.
+ */
+public class ObservableMapEx01 {
+    public static void main(String[] args){
+        List<Integer> oddList = Arrays.asList(1, 3, 5, 7);
+        Observable.fromIterable(oddList)
+                .map(num -> "1을 더한 결과: " + (num + 1))
+                .subscribe(data -> Logger.log(LogType.ON_NEXT, data));
+    }
+}

RxJava/practice/src/main/java/org/example/ex10/ObservableMapEx02.java

@@ -0,0 +1,16 @@
+package org.example.ex10;
+
+import io.reactivex.rxjava3.core.Observable;
+import org.example.utils.LogType;
+import org.example.utils.Logger;
+
+public class ObservableMapEx02 {
+    public static void main(String[] args) {
+        Observable.just("korea", "america", "canada", "paris", "japan", "china")
+                .filter(country -> country.length() == 5 )
+                .map(country -> country.toUpperCase().charAt(0) + country.substring(1))
+                .subscribe(data -> Logger.log(LogType.ON_NEXT, data));
+
+
+    }
+}