fix: guard close with null-check to avoid NPE

README.md

@@ -15,6 +15,7 @@ This repository is a forked jmyspell-core project used for OmegaT project.
   - use `isEmpty()` for condition that compare with zero length
   - fix: define `Word#hashCode`, `Word` class already has `equals` definition
   - fix: unwanted raw types
+  - fix: check nullity of stream before close
 - style: apply spotbugs
 - Quality assurance by checking with SpotBugs static code analysis
 - CI: test with GitHub Actions

src/main/java/org/dts/spell/dictionary/myspell/MySpell.java

@@ -65,10 +65,14 @@ else if (entry.getName().endsWith(".dic"))
         dStream = zipFile.getInputStream(entry) ;
     }
 
-    initFromStreams(affStream, dStream) ;    
-
-    affStream.close() ;
-    dStream.close() ;
+    initFromStreams(affStream, dStream) ;
+
+      if (affStream != null) {
+          affStream.close() ;
+      }
+      if (dStream != null) {
+          dStream.close() ;
+      }
   }
 
   public MySpell(InputStream zipStream) throws IOException