[ch05] Refactored.

src/main/java/ch01/springbook/user/UserService.java

@@ -8,6 +8,9 @@
 
 public class UserService {
 
+	public static final int MIN_LOGCOUNT_FOR_SILVER = 50;
+	public static final int MIN_RECOMMEND_FOR_GOLD = 30;
+
 	UserDao userDao;
 
 	public void setUserDao(UserDao userDao) {
@@ -20,23 +23,8 @@ public void upgradeLevels() {
 
 		for (User user : userList) {
 
-			Boolean changed = null;
-
-			if (user.getLevel() == Level.BASIC && user.getLogin() >= 50) {
-				user.setLevel(Level.SILVER);
-				changed = true;
-
-			} else if (user.getLevel() == Level.SILVER && user.getRecommend() >= 30) {
-				user.setLevel(Level.GOLD);
-				changed = true;
-			} else if (user.getLevel() == Level.GOLD) {
-				changed = false;
-			} else {
-				changed = false;
-			}
-
-			if (changed) {
-				userDao.update(user);
+			if (canUpgradeLevel(user) == true) {
+				upgradeLevel(user);
 			}
 		}
 	}
@@ -48,4 +36,21 @@ public void add(User user) {
 
 		userDao.add(user);
 	}
+
+	private boolean canUpgradeLevel(User user) {
+
+		Level currentLevel = user.getLevel();
+
+		switch (currentLevel) {
+			case BASIC: return (user.getLogin() >= MIN_LOGCOUNT_FOR_SILVER);
+			case SILVER: return (user.getRecommend() >= MIN_RECOMMEND_FOR_GOLD);
+			case GOLD: return false;
+			default: throw new IllegalArgumentException("Unknown level: " + currentLevel);
+		}
+	}
+
+	private void upgradeLevel(User user) {
+		user.upgradeLevel();
+		userDao.update(user);
+	}
 }

src/main/java/ch01/springbook/user/domain/Level.java

@@ -2,20 +2,26 @@
 
 public enum Level {
 
-	BASIC(1),
-	SILVER(2),
-	GOLD(3);
+	GOLD(3, null),
+	SILVER(2, GOLD),
+	BASIC(1, SILVER);
 
 	private final int value;
+	private final Level next;
 
-	private Level(int value) {
+	private Level(int value, Level next) {
 		this.value = value;
+		this.next = next;
 	}
 
 	public int intValue() {
 		return value;
 	}
 
+	public Level nextLevel() {
+		return this.next;
+	}
+
 	public static Level valueOf(int value) {
 		switch(value) {
 			case 1: return BASIC;

src/main/java/ch01/springbook/user/domain/User.java

@@ -69,4 +69,16 @@ public int getRecommend() {
 	public void setRecommend(int recommend) {
 		this.recommend = recommend;
 	}
+
+	public void upgradeLevel() {
+
+		Level nextLevel = level.nextLevel();
+
+		if (nextLevel == null) {
+			throw new IllegalStateException(level + " can not upgrade.");
+		} else {
+			level = nextLevel;
+		}
+
+	}
 }

src/test/java/ch01/springbook/user/UserServiceTest.java

@@ -1,5 +1,7 @@
 package ch01.springbook.user;
 
+import static ch01.springbook.user.UserService.MIN_LOGCOUNT_FOR_SILVER;
+import static ch01.springbook.user.UserService.MIN_RECOMMEND_FOR_GOLD;
 import static org.hamcrest.CoreMatchers.is;
 import static org.hamcrest.CoreMatchers.notNullValue;
 import static org.junit.Assert.assertThat;
@@ -34,11 +36,11 @@ public class UserServiceTest {
 	public void setUp() {
 
 		userList = Arrays.asList(
-			new User("test01", "test", "no1", Level.BASIC, 49, 0),
-			new User("test02", "test", "no2", Level.BASIC, 50, 0),
-			new User("test03", "test", "no3", Level.SILVER, 60, 29),
-			new User("test04", "test", "no3", Level.SILVER, 60, 30),
-			new User("test05", "test", "no3", Level.GOLD, 100, 100)
+			new User("test01", "test", "no1", Level.BASIC, MIN_LOGCOUNT_FOR_SILVER - 1, 0),
+			new User("test02", "test", "no2", Level.BASIC, MIN_LOGCOUNT_FOR_SILVER, 0),
+			new User("test03", "test", "no3", Level.SILVER, 60, MIN_RECOMMEND_FOR_GOLD - 1),
+			new User("test04", "test", "no3", Level.SILVER, 60, MIN_RECOMMEND_FOR_GOLD),
+			new User("test05", "test", "no3", Level.GOLD, 100, Integer.MAX_VALUE)
 		);
 	}
 
@@ -58,11 +60,11 @@ public void upgradeLevels() {
 
 		userService.upgradeLevels();
 
-		checkLevel(userList.get(0), Level.BASIC);
-		checkLevel(userList.get(1), Level.SILVER);
-		checkLevel(userList.get(2), Level.SILVER);
-		checkLevel(userList.get(3), Level.GOLD);
-		checkLevel(userList.get(4), Level.GOLD);
+		checkLevelUpgraded(userList.get(0), false);
+		checkLevelUpgraded(userList.get(1), true);
+		checkLevelUpgraded(userList.get(2), false);
+		checkLevelUpgraded(userList.get(3), true);
+		checkLevelUpgraded(userList.get(4), false);
 	}
 
 	@Test
@@ -84,8 +86,14 @@ public void add() {
 		assertThat(userWithoutLevelRead.getLevel(), is(Level.BASIC));
 	}
 
-	private void checkLevel(User user, Level expectedLevel) {
+	private void checkLevelUpgraded(User user, boolean upgraded) {
+
 		User userUpdate = userDao.get(user.getId());
-		assertThat(userUpdate.getLevel(), is(expectedLevel));
+
+		if (upgraded) {
+			assertThat(userUpdate.getLevel(), is(user.getLevel().nextLevel()));
+		} else {
+			assertThat(userUpdate.getLevel(), is(user.getLevel()));
+		}
 	}
 }

src/test/java/ch01/springbook/user/UserTest.java

@@ -0,0 +1,47 @@
+package ch01.springbook.user;
+
+import static org.hamcrest.CoreMatchers.is;
+import static org.junit.Assert.assertThat;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import ch01.springbook.user.domain.Level;
+import ch01.springbook.user.domain.User;
+
+public class UserTest {
+
+	User user;
+
+	@Before
+	public void setUp() {
+		user = new User();
+	}
+
+	@Test
+	public void upgradeLevel() {
+
+		Level[] levels = Level.values();
+
+		for (Level level : levels) {
+			if (level.nextLevel() == null) continue;
+
+			user.setLevel(level);
+			user.upgradeLevel();
+			assertThat(user.getLevel(), is(level.nextLevel()));
+		}
+	}
+
+	@Test(expected = IllegalStateException.class)
+	public void cannotUpgradeLevel() {
+		Level[] levels = Level.values();
+
+		for (Level level : levels) {
+			if (level.nextLevel() != null) continue;
+
+			user.setLevel(level);
+			user.upgradeLevel();
+			assertThat(user.getLevel(), is(level.nextLevel()));
+		}
+	}
+}