use builder pattern for EventManager

gradle.properties

@@ -1,5 +1,5 @@
 group = org.xbib
 name = event
-version = 0.0.5
+version = 0.0.6
 
 org.gradle.warning.mode = ALL

src/main/java/org/xbib/event/EventManager.java

@@ -25,17 +25,7 @@ public final class EventManager implements Closeable {
 
     private static final Logger logger = Logger.getLogger(EventManager.class.getName());
 
-    private static ExecutorService executorService;
-
-    private static ClassLoader classLoader;
-
-    private static AsyncEventBus eventBus;
-
-    private static List<EventConsumer> eventConsumers;
-
-    static {
-        createInstances();
-    }
+    private final Builder builder;
 
     private final ClockEventManager clockEventManager;
 
@@ -47,26 +37,17 @@ public final class EventManager implements Closeable {
 
     private final SyslogEventManager syslogEventManager;
 
-    private EventManager(Settings settings) {
-        this.clockEventManager = new ClockEventManager(settings, eventBus, classLoader);
-        this.timerEventManager = new TimerEventManager(settings, eventBus, classLoader, ZoneId.systemDefault());
-        this.fileFollowEventManager = new FileFollowEventManager(settings, eventBus, executorService, classLoader);
-        this.pathEventManager = new PathEventManager(settings, eventBus, executorService, classLoader);
-        this.syslogEventManager = new SyslogEventManager(settings, eventBus);
-    }
-
-    public static EventManager newEventManager(Settings settings) {
-        return new EventManager(settings);
-    }
-
-    public static void register(EventConsumer eventConsumer) {
-        Objects.requireNonNull(eventConsumer, "event consumer must not be null");
-        eventConsumers.add(eventConsumer);
-        eventBus.register(eventConsumer);
+    private EventManager(Builder builder) {
+        this.builder = builder;
+        this.clockEventManager = new ClockEventManager(builder.settings, builder.eventBus, builder.classLoader);
+        this.timerEventManager = new TimerEventManager(builder.settings, builder.eventBus, builder.classLoader, ZoneId.systemDefault());
+        this.fileFollowEventManager = new FileFollowEventManager(builder.settings, builder.eventBus, builder.executorService, builder.classLoader);
+        this.pathEventManager = new PathEventManager(builder.settings, builder.eventBus, builder.executorService, builder.classLoader);
+        this.syslogEventManager = new SyslogEventManager(builder.settings, builder.eventBus);
     }
 
-    public List<EventConsumer> getEventConsumers() {
-        return eventConsumers;
+    public static Builder builder(Settings settings) {
+        return new Builder(settings);
     }
 
     public ClockEventManager getClockEventManager() {
@@ -96,7 +77,7 @@ public final class EventManager implements Closeable {
 
     @Override
     public void close() throws IOException {
-        for (EventConsumer eventConsumer : eventConsumers) {
+        for (EventConsumer eventConsumer : builder.eventConsumers) {
             eventConsumer.close();
         }
         clockEventManager.close();
@@ -106,25 +87,65 @@ public final class EventManager implements Closeable {
         syslogEventManager.close();
     }
 
-    private static class EventManagerExceptionHandler implements SubscriberExceptionHandler {
-        @Override
-        public void handleException(Throwable exception, SubscriberExceptionContext context) {
-            logger.log(Level.SEVERE, exception.getMessage(), exception);
+    public static class Builder {
+
+        private final Settings settings;
+
+        private ExecutorService executorService;
+
+        private ClassLoader classLoader;
+
+        private AsyncEventBus eventBus;
+
+        private final List<EventConsumer> eventConsumers;
+
+        private Builder(Settings settings) {
+            this.settings = settings;
+            this.eventConsumers = new ArrayList<>();
+        }
+
+        public Builder setExecutorService(ExecutorService executorService) {
+            this.executorService = executorService;
+            return this;
+        }
+
+        public Builder setClassLoader(ClassLoader classLoader) {
+            this.classLoader = classLoader;
+            return this;
         }
-    }
 
-    private static void createInstances() {
-        if (executorService == null) {
-            executorService = Executors.newFixedThreadPool(2);
+        public Builder setEventBus(AsyncEventBus eventBus) {
+            this.eventBus = eventBus;
+            return this;
         }
-        if (classLoader == null) {
-            classLoader = EventManager.class.getClassLoader();
+
+        public Builder register(EventConsumer eventConsumer) {
+            Objects.requireNonNull(eventConsumer, "event consumer must not be null");
+            eventConsumers.add(eventConsumer);
+            return this;
         }
-        if (eventBus == null) {
-            eventBus = new AsyncEventBus(executorService, new EventManagerExceptionHandler());
+
+        public EventManager build() {
+            if (executorService == null) {
+                executorService = Executors.newFixedThreadPool(settings.getAsInt("event.threadcount", 2));
+            }
+            if (classLoader == null) {
+                classLoader = EventManager.class.getClassLoader();
+            }
+            if (eventBus == null) {
+                eventBus = new AsyncEventBus(executorService, new EventManagerExceptionHandler());
+            }
+            for (EventConsumer eventConsumer : eventConsumers) {
+                eventBus.register(eventConsumer);
+            }
+            return new EventManager(this);
         }
-        if (eventConsumers == null) {
-            eventConsumers = new ArrayList<>();
+    }
+
+    private static class EventManagerExceptionHandler implements SubscriberExceptionHandler {
+        @Override
+        public void handleException(Throwable exception, SubscriberExceptionContext context) {
+            logger.log(Level.SEVERE, exception.getMessage(), exception);
         }
     }
 }

src/test/java/org/xbib/event/clock/ClockEventManagerTest.java

@@ -5,20 +5,20 @@ import org.xbib.event.EventManager;
 import org.xbib.settings.Settings;
 
 import java.io.IOException;
-import java.util.logging.Logger;
 
 public class ClockEventManagerTest {
 
     @Test
     public void testEvents() throws IOException, InterruptedException {
         TestClockEventConsumer clockEventConsumer = new TestClockEventConsumer();
-        EventManager.register(clockEventConsumer);
         Settings settings = Settings.settingsBuilder()
                 .put("event.clock.testclockevent.enabled", "true")
                 .put("event.clock.testclockevent.class", "org.xbib.event.clock.TestClockEvent")
                 .put("event.clock.testclockevent.entry", "*/1 6-21 * * *")
                 .build();
-        EventManager eventManager = EventManager.newEventManager(settings);
+        EventManager eventManager = EventManager.builder(settings)
+                .register(clockEventConsumer)
+                .build();
         ClockEventManager clockEventManager = eventManager.getClockEventManager();
         Thread.sleep(90000L);
         clockEventManager.close();

src/test/java/org/xbib/event/io/file/FileFollowEventManagerTest.java

@@ -2,16 +2,12 @@ package org.xbib.event.io.file;
 
 import org.junit.jupiter.api.Test;
 import org.xbib.event.EventManager;
-import org.xbib.event.timer.TestTimerEventConsumer;
-import org.xbib.event.timer.TimerEventManager;
 import org.xbib.settings.Settings;
 
 import java.io.BufferedWriter;
 import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
-import java.time.Instant;
-import java.util.Map;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
@@ -23,14 +19,15 @@ public class FileFollowEventManagerTest {
     public void testFileFollowEvents() throws IOException, InterruptedException {
         Path path = Files.createTempDirectory("testfilefollow");
         TestFileFollowEventConsumer consumer = new TestFileFollowEventConsumer();
-        EventManager.register(consumer);
         Settings settings = Settings.settingsBuilder()
                 .put("event.filefollow.testfilefollowevent.enabled", "true")
                 .put("event.filefollow.testfilefollowevent.class", "org.xbib.event.io.file.TestFileFollowEvent")
                 .put("event.filefollow.testfilefollowevent.base", path.toString())
                 .put("event.filefollow.testfilefollowevent.pattern", ".*")
                 .build();
-        EventManager eventManager = EventManager.newEventManager(settings);
+        EventManager eventManager = EventManager.builder(settings)
+                .register(consumer)
+                .build();
         FileFollowEventManager fileFolloeEventManager = eventManager.getFileFollowEventManager();
         Thread.sleep(5000L);
         try (BufferedWriter bufferedWriter = Files.newBufferedWriter(path.resolve("test.txt"))) {

src/test/java/org/xbib/event/timer/TimerEventManagerTest.java

@@ -13,12 +13,13 @@ public class TimerEventManagerTest {
     @Test
     public void testTimerEvents() throws IOException, InterruptedException {
         TestTimerEventConsumer consumer = new TestTimerEventConsumer();
-        EventManager.register(consumer);
         Settings settings = Settings.settingsBuilder()
                 .put("event.timer.testtimerevent.enabled", "true")
                 .put("event.timer.testtimerevent.class", "org.xbib.event.timer.TestTimerEvent")
                 .build();
-        EventManager eventManager = EventManager.newEventManager(settings);
+        EventManager eventManager = EventManager.builder(settings)
+                .register(consumer)
+                .build();
         TimerEventManager timerEventManager = eventManager.getTimerEventManager();
         timerEventManager.put("testtimerevent", Instant.now().plusSeconds(5L), Map.of("a", "b"));
         Thread.sleep(10000L);