Fixed an NPE caused by stopping an EntityContainer that only partially started.

pspeed42 · pspeed42 · commit 15b2dc7245b5 · 2024-03-27T21:45:19.000-04:00
diff --git a/release-notes.md b/release-notes.md
@@ -21,6 +21,7 @@ Version 1.9.0 (unreleased)
 * Added a SystemTiming class that can optionally be given to GameSystemManager
     to track per-system timings and dump the information as a warning when
     a frame exceeds a certain threshold.
+* Fixed an NPE when stopping an EntityContainer that did not fully start.
 
 
 Version 1.8.0 (latest)
diff --git a/src/main/java/com/simsilica/es/EntityContainer.java b/src/main/java/com/simsilica/es/EntityContainer.java
@@ -1,36 +1,36 @@
 /*
  * $Id$
- * 
+ *
  * Copyright (c) 2015, Simsilica, LLC
  * All rights reserved.
- * 
+ *
  * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions 
+ * modification, are permitted provided that the following conditions
  * are met:
- * 
- * 1. Redistributions of source code must retain the above copyright 
+ *
+ * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
- * 
- * 2. Redistributions in binary form must reproduce the above copyright 
- *    notice, this list of conditions and the following disclaimer in 
- *    the documentation and/or other materials provided with the 
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
  *    distribution.
- * 
- * 3. Neither the name of the copyright holder nor the names of its 
- *    contributors may be used to endorse or promote products derived 
+ *
+ * 3. Neither the name of the copyright holder nor the names of its
+ *    contributors may be used to endorse or promote products derived
  *    from this software without specific prior written permission.
- * 
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 
- * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 
- * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 
- * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 
- * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 
- * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 
- * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  * OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
@@ -70,29 +70,29 @@
 public abstract class EntityContainer<T> {
 
     static Logger log = LoggerFactory.getLogger(EntityContainer.class);
-    
+
     private EntityData ed;
     private ComponentFilter filter;
     private Class<? extends EntityComponent>[] componentTypes;
     private EntitySet entities;
     private T[] array;
     private Map<EntityId, T> objects = new HashMap<>();
     private Class parameter;
-    
+
     @SuppressWarnings("unchecked")
     @SafeVarargs
     protected EntityContainer( EntityData ed, Class<? extends EntityComponent>... componentTypes ) {
         this(ed, null, componentTypes);
     }
- 
+
     @SuppressWarnings("unchecked")
     @SafeVarargs
     protected EntityContainer( EntityData ed, ComponentFilter filter, Class<? extends EntityComponent>... componentTypes ) {
         this.ed = ed;
         this.filter = filter;
         this.componentTypes = componentTypes;
-        
-        // Find out what the type parameter is       
+
+        // Find out what the type parameter is
         for( Type t = getClass().getGenericSuperclass(); t != null; ) {
             if( t instanceof ParameterizedType ) {
                 ParameterizedType pt = (ParameterizedType)t;
@@ -103,10 +103,10 @@ protected EntityContainer( EntityData ed, ComponentFilter filter, Class<? extend
                         parameter = (Class)pt.getActualTypeArguments()[0];
                     }
                     break;
-                } 
+                }
             } else if( t instanceof Class ) {
                 t = ((Class)t).getGenericSuperclass();
-            } else {            
+            } else {
                 t = null;
             }
         }
@@ -125,23 +125,23 @@ protected void setFilter( ComponentFilter filter ) {
     protected EntityData getEntityData() {
         return ed;
     }
-    
+
     @SuppressWarnings("unchecked")
     protected void addComponentTypes( Class<? extends EntityComponent>... add ) {
         Class[] merged = new Class[add.length + componentTypes.length];
         System.arraycopy(componentTypes, 0, merged, 0, componentTypes.length);
         System.arraycopy(add, 0, merged, componentTypes.length, add.length);
         this.componentTypes = merged;
     }
- 
+
     public int size() {
         return entities.size();
     }
 
     public T getObject( EntityId id ) {
         return objects.get(id);
     }
- 
+
     @SuppressWarnings("unchecked")
     protected T[] getArray() {
         if( array != null ) {
@@ -151,13 +151,13 @@ protected T[] getArray() {
         array = objects.values().toArray(array);
         return array;
     }
- 
+
     protected abstract T addObject( Entity e );
-    
+
     protected abstract void updateObject( T object, Entity e );
-    
-    protected abstract void removeObject( T object, Entity e );    
-    
+
+    protected abstract void removeObject( T object, Entity e );
+
     protected void addObjects( Set<Entity> set ) {
         if( set.isEmpty() ) {
             return;
@@ -168,7 +168,7 @@ protected void addObjects( Set<Entity> set ) {
         }
         array = null;
     }
-    
+
     protected void updateObjects( Set<Entity> set ) {
         if( set.isEmpty() ) {
             return;
@@ -182,7 +182,7 @@ protected void updateObjects( Set<Entity> set ) {
             updateObject(object, e);
         }
     }
-    
+
     protected void removeObjects( Set<Entity> set ) {
         if( set.isEmpty() ) {
             return;
@@ -197,13 +197,13 @@ protected void removeObjects( Set<Entity> set ) {
         }
         array = null;
     }
-    
+
     public void start() {
         this.entities = ed.getEntities(filter, componentTypes);
         entities.applyChanges();
-        addObjects(entities);   
+        addObjects(entities);
     }
-    
+
     public boolean update() {
         if( entities.applyChanges() ) {
             removeObjects(entities.getRemovedEntities());
@@ -213,17 +213,21 @@ public boolean update() {
         }
         return false;
     }
-    
+
     public void stop() {
+        if( entities == null ) {
+            // We were never started or startup failed
+            return;
+        }
         removeObjects(entities);
         this.entities.release();
         this.entities = null;
     }
-    
+
     public boolean isStarted() {
         return entities != null;
     }
-    
+
     @Override
     public String toString() {
         return getClass().getName() + "[components=" + Arrays.asList(componentTypes) + "]";
