#10 effective java: item 1

effective-java/src/main/java/com/example/effectivejava/EffectiveJavaApplication.java

@@ -0,0 +1,13 @@
+package com.example.effectivejava;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class EffectiveJavaApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(EffectiveJavaApplication.class, args);
+    }
+
+}

effective-java/src/main/java/com/example/effectivejava/chapter01/item01/Difficulty.java

@@ -0,0 +1,6 @@
+package com.example.effectivejava.chapter01.item01;
+
+public enum Difficulty {
+
+    EASY, NORMAL, HARD, HELL
+}

effective-java/src/main/java/com/example/effectivejava/chapter01/item01/HelloService.java

@@ -0,0 +1,28 @@
+package com.example.effectivejava.chapter01.item01;
+
+public interface HelloService {
+
+    String hello();
+
+    static String hi() {
+        prepareMessage();
+        return "hi";
+    }
+
+    static private void prepareMessage() {
+    }
+
+    static String hi1() {
+        prepareMessage();
+        return "hi";
+    }
+
+    static String hi2() {
+        prepareMessage();
+        return "hi";
+    }
+
+    default String bye() {
+        return "bye";
+    }
+}

effective-java/src/main/java/com/example/effectivejava/chapter01/item01/HelloServiceFactory.java

@@ -0,0 +1,15 @@
+package com.example.effectivejava.chapter01.item01;
+
+import java.util.Optional;
+import java.util.ServiceLoader;
+
+public class HelloServiceFactory {
+
+    public static void main(String[] args) {
+        ServiceLoader<HelloService> loader = ServiceLoader.load(HelloService.class);
+        Optional<HelloService> helloServiceOptional = loader.findFirst();
+        helloServiceOptional.ifPresent(h -> {
+            System.out.println(h.hello());
+        });
+    }
+}

effective-java/src/main/java/com/example/effectivejava/chapter01/item01/Order.java

@@ -0,0 +1,37 @@
+package com.example.effectivejava.chapter01.item01;
+
+import java.util.EnumSet;
+
+public class Order {
+
+    private boolean prime;
+
+    private boolean urgent;
+
+    private Product product;
+
+    private OrderStatus orderStatus;
+
+    public static Order primeOrder(Product product) {
+        Order order = new Order();
+        order.prime = true;
+        order.product = product;
+
+        return order;
+    }
+
+    public static Order urgentOrder(Product product) {
+        Order order = new Order();
+        order.urgent = true;
+        order.product = product;
+        return order;
+    }
+
+    public static void main(String[] args) {
+
+        Order order = new Order();
+        if (order.orderStatus == OrderStatus.DELIVERED) {
+            System.out.println("delivered");
+        }
+    }
+}

effective-java/src/main/java/com/example/effectivejava/chapter01/item01/OrderStatus.java

@@ -0,0 +1,12 @@
+package com.example.effectivejava.chapter01.item01;
+
+public enum OrderStatus {
+
+    PREPARING(0), SHIPPED(1), DELIVERING(2), DELIVERED(3);
+
+    private int number;
+
+    OrderStatus(int number) {
+        this.number = number;
+    }
+}

effective-java/src/main/java/com/example/effectivejava/chapter01/item01/Product.java

@@ -0,0 +1,17 @@
+package com.example.effectivejava.chapter01.item01;
+
+import java.util.EnumSet;
+
+public class Product {
+
+    public static void main(String[] args) {
+        Settings settings1 = Settings.getInstance();
+        Settings settings2 = Settings.getInstance();
+
+        System.out.println(settings1);
+        System.out.println(settings2);
+
+        Boolean.valueOf(false);
+        EnumSet.allOf(Difficulty.class);
+    }
+}

effective-java/src/main/java/com/example/effectivejava/chapter01/item01/Settings.java

@@ -0,0 +1,22 @@
+package com.example.effectivejava.chapter01.item01;
+
+/**
+ * 이 클래스의 인스턴스는 #getInstance()를 통해 사용한다.
+ * @see #getInstance()
+ */
+public class Settings {
+
+    private boolean useAutoSteering;
+
+    private boolean useABS;
+
+    private Difficulty difficulty;
+
+    private Settings() {}
+
+    private static final Settings SETTINGS = new Settings();
+
+    public static Settings getInstance() {
+        return SETTINGS;
+    }
+}

effective-java/src/main/resources/application.properties

@@ -0,0 +1 @@
+

effective-java/src/test/java/com/example/effectivejava/EffectiveJavaApplicationTests.java

@@ -0,0 +1,13 @@
+package com.example.effectivejava;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.boot.test.context.SpringBootTest;
+
+@SpringBootTest
+class EffectiveJavaApplicationTests {
+
+    @Test
+    void contextLoads() {
+    }
+
+}