allow to rethrow bootstrap exceptions fix #576

Author: jknack

jooby/src/main/java/org/jooby/Jooby.java

@@ -693,6 +693,8 @@ public EnvDep(final Predicate<String> predicate, final Consumer<Config> callback
 
   private transient boolean defaultExecSet;
 
+  private boolean throwBootstrapException;
+
   /**
    * Creates a new {@link Jooby} application.
    */
@@ -1920,7 +1922,13 @@ public void start(final String... args) {
     try {
       start(args, null);
     } catch (Throwable x) {
-      stop(Optional.of(x));
+      stop();
+      String msg = "An error occurred while starting the application:";
+      if (throwBootstrapException) {
+        throw new Err(Status.SERVICE_UNAVAILABLE, msg, x);
+      } else {
+        logger(this).error(msg, x);
+      }
     }
   }
 
@@ -2373,6 +2381,36 @@ public Jooby executor(final String name) {
     return this;
   }
 
+  /**
+   * If the application fails to start all the services are shutdown. Also, the exception is logged
+   * and usually the application is going to exit.
+   *
+   * This options turn off logging and rethrow the exception as {@link Err}. Here is an example:
+   *
+   * <pre>
+   * public class App extends Jooby {
+   *   {
+   *     throwBootstrapException();
+   *     ...
+   *   }
+   * }
+   *
+   * App app = new App();
+   *
+   * try {
+   *   app.start();
+   * } catch (Err err) {
+   *   Throwable cause = err.getCause();
+   * }
+   * </pre>
+   *
+   * @return
+   */
+  public Jooby throwBootstrapException() {
+    this.throwBootstrapException = true;
+    return this;
+  }
+
   /**
    * Run app in javascript.
    *
@@ -2782,13 +2820,6 @@ private static List<Config> modconf(final Collection<Object> bag) {
         .collect(Collectors.toList());
   }
 
-  /**
-   * Stop the application, close all the modules and stop the web server.
-   */
-  public void stop() {
-    stop(Optional.empty());
-  }
-
   /**
    * Test if the application is up and running.
    *
@@ -2798,12 +2829,14 @@ public boolean isStarted() {
     return started.get();
   }
 
-  private void stop(final Optional<Throwable> x) {
+  /**
+   * Stop the application, close all the modules and stop the web server.
+   */
+  public void stop() {
     if (started.compareAndSet(true, false)) {
       Logger log = logger(this);
 
-      x.ifPresent(c -> log.error("An error occurred while starting the application:", c));
-      fireStop(injector, this, log, onStop);
+      fireStop(this, log, onStop);
       if (injector != null) {
         try {
           injector.getInstance(Server.class).stop();
@@ -2817,7 +2850,7 @@ private void stop(final Optional<Throwable> x) {
     }
   }
 
-  private static void fireStop(final Injector injector, final Jooby app, final Logger log,
+  private static void fireStop(final Jooby app, final Logger log,
       final List<CheckedConsumer<Registry>> onStop) {
     // stop services
     onStop.forEach(c -> Try.run(() -> c.accept(app))

jooby/src/test/java/org/jooby/issues/Issue576.java

@@ -0,0 +1,33 @@
+package org.jooby.issues;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
+
+import org.jooby.Err;
+import org.jooby.Jooby;
+import org.jooby.Status;
+import org.junit.Test;
+
+public class Issue576 {
+
+  @Test
+  public void shouldThrowBootstrapException() {
+    IllegalStateException ies = new IllegalStateException("boot err");
+    try {
+      new Jooby() {
+        {
+          throwBootstrapException();
+
+          onStart(() -> {
+            throw ies;
+          });
+        }
+      }.start();
+      fail();
+    } catch (Err err) {
+      assertEquals(Status.SERVICE_UNAVAILABLE.value(), err.statusCode());
+      assertEquals(ies, err.getCause());
+    }
+  }
+
+}