Don't create separate instances for NullFileHandler, but rather use a common static instance

This can save some memory during regression testing.

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1875268 13f79535-47bb-0310-9956-ffa450edef68

2 files changed, 60 insertions, 58 deletions

diff --git a/src/integrationtest/org/apache/poi/POIFileScanner.java b/src/integrationtest/org/apache/poi/POIFileScanner.java
index 6ad0ff3458..db6030f738 100644
--- a/src/integrationtest/org/apache/poi/POIFileScanner.java
+++ b/src/integrationtest/org/apache/poi/POIFileScanner.java
@@ -139,7 +139,7 @@ public class POIFileScanner {
                         }
                     } catch (IOException | RuntimeException e2) {
                         System.out.println("Could not open POIFSFileSystem for OLE2 file " + testFile + ": " + e + " and " + e2);
-                        return new TestAllFiles.NullFileHandler();
+                        return TestAllFiles.NullFileHandler.instance;
                     }
                 }
             }
@@ -159,7 +159,7 @@ public class POIFileScanner {
                         }
                     } catch (IOException | RuntimeException e2) {
                         System.out.println("Could not open POIFSFileSystem for OOXML file " + testFile + ": " + e + " and " + e2);
-                        return new TestAllFiles.NullFileHandler();
+                        return TestAllFiles.NullFileHandler.instance;
                     }
                 }
             }
@@ -168,12 +168,12 @@ public class POIFileScanner {
             case RTF:
             case PDF:
             case HTML:
-                return new TestAllFiles.NullFileHandler();
+                return TestAllFiles.NullFileHandler.instance;
         }
 
         System.out.println("Did not get a handler for extension " + TestAllFiles.getExtension(file) +
                 " of file " + file + ": " + magic);
-        return new TestAllFiles.NullFileHandler();
+        return TestAllFiles.NullFileHandler.instance;
     }
 
     @Ignore
diff --git a/src/integrationtest/org/apache/poi/TestAllFiles.java b/src/integrationtest/org/apache/poi/TestAllFiles.java
index 7a573981b5..6a54ba2d45 100644
--- a/src/integrationtest/org/apache/poi/TestAllFiles.java
+++ b/src/integrationtest/org/apache/poi/TestAllFiles.java
@@ -146,8 +146,8 @@ public class TestAllFiles {
         HANDLERS.put(".vstx", new XDGFFileHandler());
 
         // Visio - not handled yet
-        HANDLERS.put(".vst", new NullFileHandler());
-        HANDLERS.put(".vss", new NullFileHandler());
+        HANDLERS.put(".vst", NullFileHandler.instance);
+        HANDLERS.put(".vss", NullFileHandler.instance);
 
         // POIFS
         HANDLERS.put(".ole2", new POIFSFileHandler());
@@ -159,65 +159,65 @@ public class TestAllFiles {
         HANDLERS.put(".dat", IGNORE_SCRATCHPAD ? new HPSFFileHandler() : new HMEFFileHandler());
 
         // TODO: are these readable by some of the formats?
-        HANDLERS.put(".wri", new NullFileHandler());
-        HANDLERS.put(".shw", new NullFileHandler());
-        HANDLERS.put(".zvi", new NullFileHandler());
-        HANDLERS.put(".mpp", new NullFileHandler());
-        HANDLERS.put(".qwp", new NullFileHandler());
-        HANDLERS.put(".wps", new NullFileHandler());
-        HANDLERS.put(".bin", new NullFileHandler());
-        HANDLERS.put(".xps", new NullFileHandler());
-        HANDLERS.put(".sldprt", new NullFileHandler());
-        HANDLERS.put(".mdb", new NullFileHandler());
-        HANDLERS.put(".vml", new NullFileHandler());
+        HANDLERS.put(".wri", NullFileHandler.instance);
+        HANDLERS.put(".shw", NullFileHandler.instance);
+        HANDLERS.put(".zvi", NullFileHandler.instance);
+        HANDLERS.put(".mpp", NullFileHandler.instance);
+        HANDLERS.put(".qwp", NullFileHandler.instance);
+        HANDLERS.put(".wps", NullFileHandler.instance);
+        HANDLERS.put(".bin", NullFileHandler.instance);
+        HANDLERS.put(".xps", NullFileHandler.instance);
+        HANDLERS.put(".sldprt", NullFileHandler.instance);
+        HANDLERS.put(".mdb", NullFileHandler.instance);
+        HANDLERS.put(".vml", NullFileHandler.instance);
 
         // ignore some file types, images, other formats, ...
-        HANDLERS.put(".txt", new NullFileHandler());
-        HANDLERS.put(".pdf", new NullFileHandler());
-        HANDLERS.put(".rtf", new NullFileHandler());
-        HANDLERS.put(".gif", new NullFileHandler());
-        HANDLERS.put(".html", new NullFileHandler());
-        HANDLERS.put(".png", new NullFileHandler());
-        HANDLERS.put(".wmf", new NullFileHandler());
-        HANDLERS.put(".emf", new NullFileHandler());
-        HANDLERS.put(".dib", new NullFileHandler());
-        HANDLERS.put(".svg", new NullFileHandler());
-        HANDLERS.put(".pict", new NullFileHandler());
-        HANDLERS.put(".jpg", new NullFileHandler());
-        HANDLERS.put(".jpeg", new NullFileHandler());
-        HANDLERS.put(".tif", new NullFileHandler());
-        HANDLERS.put(".tiff", new NullFileHandler());
-        HANDLERS.put(".wav", new NullFileHandler());
-        HANDLERS.put(".xml", new NullFileHandler());
-        HANDLERS.put(".csv", new NullFileHandler());
-        HANDLERS.put(".ods", new NullFileHandler());
-        HANDLERS.put(".ttf", new NullFileHandler());
-        HANDLERS.put(".fntdata", new NullFileHandler());
+        HANDLERS.put(".txt", NullFileHandler.instance);
+        HANDLERS.put(".pdf", NullFileHandler.instance);
+        HANDLERS.put(".rtf", NullFileHandler.instance);
+        HANDLERS.put(".gif", NullFileHandler.instance);
+        HANDLERS.put(".html", NullFileHandler.instance);
+        HANDLERS.put(".png", NullFileHandler.instance);
+        HANDLERS.put(".wmf", NullFileHandler.instance);
+        HANDLERS.put(".emf", NullFileHandler.instance);
+        HANDLERS.put(".dib", NullFileHandler.instance);
+        HANDLERS.put(".svg", NullFileHandler.instance);
+        HANDLERS.put(".pict", NullFileHandler.instance);
+        HANDLERS.put(".jpg", NullFileHandler.instance);
+        HANDLERS.put(".jpeg", NullFileHandler.instance);
+        HANDLERS.put(".tif", NullFileHandler.instance);
+        HANDLERS.put(".tiff", NullFileHandler.instance);
+        HANDLERS.put(".wav", NullFileHandler.instance);
+        HANDLERS.put(".xml", NullFileHandler.instance);
+        HANDLERS.put(".csv", NullFileHandler.instance);
+        HANDLERS.put(".ods", NullFileHandler.instance);
+        HANDLERS.put(".ttf", NullFileHandler.instance);
+        HANDLERS.put(".fntdata", NullFileHandler.instance);
         // VBA source files
-        HANDLERS.put(".vba", new NullFileHandler());
-        HANDLERS.put(".bas", new NullFileHandler());
-        HANDLERS.put(".frm", new NullFileHandler());
-        HANDLERS.put(".frx", new NullFileHandler()); //binary
-        HANDLERS.put(".cls", new NullFileHandler());
+        HANDLERS.put(".vba", NullFileHandler.instance);
+        HANDLERS.put(".bas", NullFileHandler.instance);
+        HANDLERS.put(".frm", NullFileHandler.instance);
+        HANDLERS.put(".frx", NullFileHandler.instance); //binary
+        HANDLERS.put(".cls", NullFileHandler.instance);
 
         // map some files without extension
-        HANDLERS.put("spreadsheet/BigSSTRecord", new NullFileHandler());
-        HANDLERS.put("spreadsheet/BigSSTRecord2", new NullFileHandler());
-        HANDLERS.put("spreadsheet/BigSSTRecord2CR1", new NullFileHandler());
-        HANDLERS.put("spreadsheet/BigSSTRecord2CR2", new NullFileHandler());
-        HANDLERS.put("spreadsheet/BigSSTRecord2CR3", new NullFileHandler());
-        HANDLERS.put("spreadsheet/BigSSTRecord2CR4", new NullFileHandler());
-        HANDLERS.put("spreadsheet/BigSSTRecord2CR5", new NullFileHandler());
-        HANDLERS.put("spreadsheet/BigSSTRecord2CR6", new NullFileHandler());
-        HANDLERS.put("spreadsheet/BigSSTRecord2CR7", new NullFileHandler());
-        HANDLERS.put("spreadsheet/BigSSTRecordCR", new NullFileHandler());
-        HANDLERS.put("spreadsheet/test_properties1", new NullFileHandler());
+        HANDLERS.put("spreadsheet/BigSSTRecord", NullFileHandler.instance);
+        HANDLERS.put("spreadsheet/BigSSTRecord2", NullFileHandler.instance);
+        HANDLERS.put("spreadsheet/BigSSTRecord2CR1", NullFileHandler.instance);
+        HANDLERS.put("spreadsheet/BigSSTRecord2CR2", NullFileHandler.instance);
+        HANDLERS.put("spreadsheet/BigSSTRecord2CR3", NullFileHandler.instance);
+        HANDLERS.put("spreadsheet/BigSSTRecord2CR4", NullFileHandler.instance);
+        HANDLERS.put("spreadsheet/BigSSTRecord2CR5", NullFileHandler.instance);
+        HANDLERS.put("spreadsheet/BigSSTRecord2CR6", NullFileHandler.instance);
+        HANDLERS.put("spreadsheet/BigSSTRecord2CR7", NullFileHandler.instance);
+        HANDLERS.put("spreadsheet/BigSSTRecordCR", NullFileHandler.instance);
+        HANDLERS.put("spreadsheet/test_properties1", NullFileHandler.instance);
 
         // keystore files
-        HANDLERS.put(".pfx", new NullFileHandler());
-        HANDLERS.put(".pem", new NullFileHandler());
-        HANDLERS.put(".jks", new NullFileHandler());
-        HANDLERS.put(".pkcs12", new NullFileHandler());
+        HANDLERS.put(".pfx", NullFileHandler.instance);
+        HANDLERS.put(".pem", NullFileHandler.instance);
+        HANDLERS.put(".jks", NullFileHandler.instance);
+        HANDLERS.put(".pkcs12", NullFileHandler.instance);
 
         Map<String,String> passmap = new HashMap<>();
         passmap.put("slideshow/Password_Protected-hello.ppt", "hello");
@@ -484,6 +484,8 @@ public class TestAllFiles {
     }
 
     public static class NullFileHandler implements FileHandler {
+        public static final FileHandler instance = new NullFileHandler();
+
         @Override
         public void handleFile(InputStream stream, String path) {
         }