rxjava : lambda

RxJava/basic/src/_01_lambda/ExInterface.java

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+package _01_lambda;
+
+public interface ExInterface {
+
+    void getMsg();
+
+    default String defaultMethod() {
+        return "default method";
+    }
+
+    static void print(String msg) {
+        System.out.println("msg = " + msg);
+    }
+}

RxJava/basic/src/_01_lambda/LambdaEx_01.java

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+package _01_lambda;
+
+public class LambdaEx_01 {
+
+    public static void main(String[] args) {
+
+        ExInterface.print("interface static method test");
+
+        ExInterface exInterface = () -> System.out.println("implement abstract method");
+
+        exInterface.getMsg();
+
+        String result = exInterface.defaultMethod();
+        System.out.println("result = " + result);
+
+    }
+}

RxJava/basic/src/_01_lambda/LambdaEx_02.java

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+package _01_lambda;
+
+public class LambdaEx_02 {
+
+    public static void main(String[] args) {
+
+        // 람다 사용 X
+        new Thread(new Runnable() {
+            @Override
+            public void run() {
+                System.out.println("Run Thread");
+            }
+        }).start();
+
+        // 람다 사용
+        new Thread(() -> System.out.println("Lambda Run Thread")).start();
+    }
+}

RxJava/basic/src/_01_lambda/LambdaEx_03.java

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+package _01_lambda;
+
+public class LambdaEx_03 {
+
+    @FunctionalInterface
+    interface MyFunction1 {
+        int calc(int a);
+    }
+
+    @FunctionalInterface
+    interface MyFunction2 {
+        int calc(int a, int b);
+    }
+
+    @FunctionalInterface
+    interface MyFunction3 {
+        void print();
+    }
+
+    public static void main(String[] args) {
+
+        // 파라미터가 1개인 람다식
+        MyFunction1 result1 = (x) -> { return x + x; };
+        MyFunction1 result2 = x -> x + x; // 괄호 생략 가능
+        System.out.println("result1 = " + result1.calc(5));
+        System.out.println("result2 = " + result2.calc(5));
+
+        // 파라미터가 2개인 람다식
+        MyFunction2 add = (x, y) -> x + y;
+        MyFunction2 minus = (x, y) -> x - y;
+        System.out.println("add = " + add.calc(1, 2));
+        System.out.println("minus = " + minus.calc(1, 2));
+
+        // 파라미터가 없는 람다식
+        MyFunction3 myFunction3 = () -> System.out.println("print method");
+        myFunction3.print();
+
+        // 함수형 인터페이스 파라미터로 전달
+        printSum(3, 4, (x, y) -> x * y);
+
+    }
+
+    static void printSum(int x, int y, MyFunction2 f) {
+        System.out.println(f.calc(x, y));
+    }
+}

RxJava/basic/src/_01_lambda/LambdaEx_04.java

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+package _01_lambda;
+
+public class LambdaEx_04 {
+
+    @FunctionalInterface
+    interface MyFunction3 {
+        void print();
+    }
+
+    public static void main(String[] args) {
+
+        //
+    }
+}