add ScheduleManager

src/main/java/ghast/ScheduleManager.java

@@ -0,0 +1,92 @@
+package ghast;
+
+import com.google.common.util.concurrent.ThreadFactoryBuilder;
+import lombok.AccessLevel;
+import lombok.NoArgsConstructor;
+import lombok.experimental.UtilityClass;
+import org.bukkit.Bukkit;
+import org.bukkit.scheduler.BukkitScheduler;
+
+import java.util.concurrent.*;
+
+@UtilityClass
+@SuppressWarnings("unused")
+public class ScheduleManager {
+
+	private static final ThreadFactory THREAD_FACTORY = new ThreadFactoryBuilder()
+			.setNameFormat("ScheduleManager-Thread-%d")
+			.setDaemon(true)
+			.build();
+
+	public Builder createTask() {
+		return new Builder();
+	}
+
+	@NoArgsConstructor(access = AccessLevel.PRIVATE)
+	public static class Builder {
+
+		private static final long MS_PER_ONE_TICK = 1000L/*one second by ms*/ / 20L/*tick per second*/;
+		private boolean useBukkitScheduler = false;
+		private Long afterMs;
+		private Long everyMs;
+
+		public Builder useBukkitScheduler() {
+			this.useBukkitScheduler = true;
+			return this;
+		}
+
+		public Builder after(long value, TimeUnit unit) {
+			this.afterMs = unit.toMillis(value);
+			return this;
+		}
+
+		public Builder every(long value, TimeUnit unit) {
+			this.everyMs = unit.toMillis(value);
+			return this;
+		}
+
+		public void execute(Runnable runnable) {
+			if (useBukkitScheduler) {
+				createBukkitSchedule(runnable);
+			} else {
+				createSchedule(runnable);
+			}
+		}
+
+		private void createBukkitSchedule(Runnable runnable) {
+			BukkitScheduler bukkitScheduler = Bukkit.getScheduler();
+
+			if (this.afterMs == null && this.everyMs == null) {
+				bukkitScheduler.runTask(GhastTools.getPlugin(), runnable);
+			} else if (this.everyMs != null) {
+				long everyTicks = this.everyMs / MS_PER_ONE_TICK;
+				long afterTicks = this.afterMs != null ? this.afterMs / MS_PER_ONE_TICK : 0;
+				bukkitScheduler.runTaskTimer(GhastTools.getPlugin(), runnable, afterTicks, everyTicks);
+			} else {
+				long ticks = this.afterMs / MS_PER_ONE_TICK;
+				bukkitScheduler.runTaskLater(GhastTools.getPlugin(), runnable, ticks);
+			}
+		}
+
+		private void createSchedule(Runnable runnable) {
+			ExecutorService executorService;
+
+			if (this.afterMs == null && this.everyMs == null) {
+				executorService = Executors.newSingleThreadExecutor(THREAD_FACTORY);
+				executorService.execute(runnable);
+			} else if (this.everyMs != null) {
+				ScheduledExecutorService scheduledExecutorService = Executors.newScheduledThreadPool(1, THREAD_FACTORY);
+				scheduledExecutorService.scheduleAtFixedRate(runnable,
+						this.afterMs != null ? this.afterMs : 0,
+						everyMs, TimeUnit.MILLISECONDS);
+				executorService = scheduledExecutorService;
+			} else {
+				ScheduledExecutorService scheduledExecutorService = Executors.newScheduledThreadPool(1, THREAD_FACTORY);
+				scheduledExecutorService.schedule(runnable, afterMs, TimeUnit.MILLISECONDS);
+				executorService = scheduledExecutorService;
+			}
+
+			executorService.shutdown();
+		}
+	}
+}