implemented restarter to move control over the restart process to the core

scm-webapp/src/main/java/sonia/scm/lifecycle/DefaultRestarter.java

@@ -0,0 +1,41 @@
+package sonia.scm.lifecycle;
+
+import com.google.common.annotations.VisibleForTesting;
+import sonia.scm.event.ScmEventBus;
+
+import javax.inject.Inject;
+import javax.inject.Singleton;
+
+@Singleton
+public class DefaultRestarter implements Restarter {
+
+  private ScmEventBus eventBus;
+  private RestartStrategy strategy;
+
+  @Inject
+  public DefaultRestarter() {
+    this(
+      ScmEventBus.getInstance(),
+      RestartStrategy.get(Thread.currentThread().getContextClassLoader()).orElse(null)
+    );
+  }
+
+  @VisibleForTesting
+  DefaultRestarter(ScmEventBus eventBus, RestartStrategy strategy) {
+    this.eventBus = eventBus;
+    this.strategy = strategy;
+  }
+
+  @Override
+  public boolean isSupported() {
+    return strategy != null;
+  }
+
+  @Override
+  public void restart(Class<?> cause, String reason) {
+    if (!isSupported()) {
+      throw new RestartNotSupportedException("restarting is not supported");
+    }
+    eventBus.post(new RestartEvent(cause, reason));
+  }
+}

scm-webapp/src/main/java/sonia/scm/lifecycle/RestartNotSupportedException.java

@@ -1,10 +0,0 @@
-package sonia.scm.lifecycle;
-
-/**
- * Exception is thrown if a restart is not supported or a restart strategy is misconfigured.
- */
-public class RestartNotSupportedException extends RuntimeException {
-  RestartNotSupportedException(String message, Throwable cause) {
-    super(message, cause);
-  }
-}

scm-webapp/src/main/java/sonia/scm/lifecycle/modules/BootstrapModule.java

@@ -9,6 +9,8 @@ import sonia.scm.SCMContext;
 import sonia.scm.SCMContextProvider;
 import sonia.scm.io.DefaultFileSystem;
 import sonia.scm.io.FileSystem;
+import sonia.scm.lifecycle.DefaultRestarter;
+import sonia.scm.lifecycle.Restarter;
 import sonia.scm.plugin.PluginLoader;
 import sonia.scm.repository.RepositoryLocationResolver;
 import sonia.scm.repository.xml.MetadataStore;
@@ -61,6 +63,8 @@ public class BootstrapModule extends AbstractModule {
 
     bind(FileSystem.class, DefaultFileSystem.class);
 
+    bind(Restarter.class, DefaultRestarter.class);
+
     // note CipherUtil uses an other generator
     bind(CipherHandler.class).toInstance(CipherUtil.getInstance().getCipherHandler());