Index: trunk/src/org/openstreetmap/josm/data/cache/JCSCachedTileLoaderJob.java
===================================================================
--- trunk/src/org/openstreetmap/josm/data/cache/JCSCachedTileLoaderJob.java	(revision 10876)
+++ trunk/src/org/openstreetmap/josm/data/cache/JCSCachedTileLoaderJob.java	(revision 10877)
@@ -25,4 +25,5 @@
 import org.openstreetmap.josm.data.cache.ICachedLoaderListener.LoadResult;
 import org.openstreetmap.josm.data.preferences.IntegerProperty;
+import org.openstreetmap.josm.tools.CheckParameterUtil;
 import org.openstreetmap.josm.tools.HttpClient;
 import org.openstreetmap.josm.tools.Utils;
@@ -109,5 +110,5 @@
             Map<String, String> headers,
             ThreadPoolExecutor downloadJobExecutor) {
-
+        CheckParameterUtil.ensureParameterNotNull(cache, "cache");
         this.cache = cache;
         this.now = System.currentTimeMillis();
Index: trunk/src/org/openstreetmap/josm/data/imagery/TMSCachedTileLoader.java
===================================================================
--- trunk/src/org/openstreetmap/josm/data/imagery/TMSCachedTileLoader.java	(revision 10876)
+++ trunk/src/org/openstreetmap/josm/data/imagery/TMSCachedTileLoader.java	(revision 10877)
@@ -17,4 +17,5 @@
 import org.openstreetmap.josm.data.cache.HostLimitQueue;
 import org.openstreetmap.josm.data.preferences.IntegerProperty;
+import org.openstreetmap.josm.tools.CheckParameterUtil;
 import org.openstreetmap.josm.tools.Utils;
 
@@ -43,5 +44,4 @@
     public static final IntegerProperty HOST_LIMIT = new IntegerProperty("imagery.tms.tmsloader.maxjobsperhost", 6);
 
-
     /**
      * separate from JCS thread pool for TMS loader, so we can have different thread pools for default JCS
@@ -64,4 +64,5 @@
     public TMSCachedTileLoader(TileLoaderListener listener, ICacheAccess<String, BufferedImageCacheEntry> cache,
             int connectTimeout, int readTimeout, Map<String, String> headers) throws IOException {
+        CheckParameterUtil.ensureParameterNotNull(cache, "cache");
         this.cache = cache;
         this.connectTimeout = connectTimeout;