Merge pull request #3636 from ebean-orm/feature/explicit-shutdownHook

Add DatabaseBuilder.shutdownHook option (programmatic disabling registration of JVM shutdown hook)

Author: rbygrave

ebean-api/src/main/java/io/ebean/DatabaseBuilder.java

@@ -1062,6 +1062,11 @@ default DatabaseBuilder skipDataSourceCheck(boolean skipDataSourceCheck) {
    */
   DatabaseBuilder readOnlyDatabase(boolean readOnlyDatabase);
 
+  /**
+   * Set to false such that the instance does not register a JVM shutdown hook.
+   */
+  DatabaseBuilder shutdownHook(boolean shutdownHook);
+
   /**
    * Set a DataSource.
    */
@@ -2643,6 +2648,11 @@ interface Settings extends DatabaseBuilder {
      */
     boolean readOnlyDatabase();
 
+    /**
+     * Return if a JVM shutdown hook should be registered.
+     */
+    boolean shutdownHook();
+
     /**
      * Return the DataSource.
      */

ebean-api/src/main/java/io/ebean/config/DatabaseConfig.java

@@ -311,6 +311,7 @@ public class DatabaseConfig implements DatabaseBuilder.Settings {
   private boolean skipDataSourceCheck;
 
   private boolean readOnlyDatabase;
+  private boolean shutdownHook = true;
 
   /**
    * The data source (if programmatically provided).
@@ -1365,6 +1366,17 @@ public boolean readOnlyDatabase() {
     return readOnlyDatabase;
   }
 
+  @Override
+  public DatabaseBuilder shutdownHook(boolean shutdownHook) {
+    this.shutdownHook = shutdownHook;
+    return this;
+  }
+
+  @Override
+  public boolean shutdownHook() {
+    return shutdownHook;
+  }
+
   @Override
   public DataSource getDataSource() {
     return dataSource;
@@ -2137,6 +2149,7 @@ protected void loadSettings(PropertiesWrapper p) {
     loadDocStoreSettings(p);
 
     defaultServer = p.getBoolean("defaultServer", defaultServer);
+    shutdownHook = p.getBoolean("shutdownHook", shutdownHook);
     readOnlyDatabase = p.getBoolean("readOnlyDatabase", readOnlyDatabase);
     autoPersistUpdates = p.getBoolean("autoPersistUpdates", autoPersistUpdates);
     loadModuleInfo = p.getBoolean("loadModuleInfo", loadModuleInfo);

ebean-api/src/main/java/io/ebean/event/ShutdownManager.java

@@ -97,8 +97,7 @@ public static void deregisterShutdownHook() {
   private static void registerShutdownHook() {
     lock.lock();
     try {
-      String value = System.getProperty("ebean.registerShutdownHook");
-      if (value == null || !value.trim().equalsIgnoreCase("false")) {
+      if ("true".equalsIgnoreCase(System.getProperty("ebean.registerShutdownHook", "true"))) {
         Runtime.getRuntime().addShutdownHook(shutdownHook);
       }
     } catch (IllegalStateException ex) {

ebean-api/src/test/java/io/ebean/config/DatabaseConfigTest.java

@@ -79,6 +79,7 @@ void testLoadWithProperties() {
     props.setProperty("includeLabelInSql", "false");
     props.setProperty("lazyLoadBatchSize", "50");
     props.setProperty("queryBatchSize", "60");
+    props.setProperty("shutdownHook", "false");
 
     props.setProperty("queryPlan.enable", "true");
     props.setProperty("queryPlan.thresholdMicros", "10000");
@@ -100,6 +101,7 @@ void testLoadWithProperties() {
     assertTrue(settings.isLoadModuleInfo());
     assertTrue(settings.skipDataSourceCheck());
     assertTrue(settings.readOnlyDatabase());
+    assertFalse(settings.shutdownHook());
     assertFalse(settings.isIncludeLabelInSql());
     assertThat(settings.getLengthCheck()).isEqualTo(LengthCheck.ON);
     assertThat(settings.getLazyLoadBatchSize()).isEqualTo(50);
@@ -172,6 +174,7 @@ void test_defaults() {
     DatabaseBuilder.Settings config = new DatabaseConfig().settings();
     assertTrue(config.isIdGeneratorAutomatic());
     assertTrue(config.isDefaultServer());
+    assertTrue(config.shutdownHook());
     assertFalse(config.isAutoPersistUpdates());
     assertFalse(config.skipDataSourceCheck());
 
@@ -196,6 +199,8 @@ void test_defaults() {
     assertThat(config.getLengthCheck()).isEqualTo(LengthCheck.OFF);
     assertTrue(config.isIncludeLabelInSql());
 
+    config.shutdownHook(false);
+    assertFalse(config.shutdownHook());
     config.setLoadModuleInfo(false);
     assertFalse(config.isAutoLoadModuleInfo());
     assertFalse(config.isLoadModuleInfo());

ebean-core/src/main/java/io/ebeaninternal/server/core/DefaultServer.java

@@ -162,8 +162,10 @@ public DefaultServer(InternalConfiguration config, ServerCacheManager cache) {
     this.scriptRunner = new DScriptRunner(this);
 
     configureServerPlugins();
-    // Register with the JVM Shutdown hook
-    ShutdownManager.registerDatabase(this);
+    if (this.config.shutdownHook() && "true".equalsIgnoreCase(System.getProperty("ebean.registerShutdownHook", "true"))) {
+      // register with the JVM Shutdown hook
+      ShutdownManager.registerDatabase(this);
+    }
   }
 
   /**