Static classes

src/main/java/io/github/spair/byond/dmi/DmiSlurper.java

@@ -19,9 +19,6 @@
 @SuppressWarnings("WeakerAccess")
 public final class DmiSlurper {
 
-    private final MetaExtractor metaExtractor = new MetaExtractor();
-    private final StateExtractor stateExtractor = new StateExtractor();
-
     /**
      * Static method to process file. Same as {@link #slurpUp(File)},
      * with {@link DmiSlurper} instantiation under the hood.
@@ -102,8 +99,8 @@ public Dmi slurpUp(final String dmiName, final InputStream input) {
             BufferedImage dmiImage = ImageIO.read(bufferedInput);
             bufferedInput.reset();
 
-            DmiMeta dmiMeta = metaExtractor.extractMetadata(bufferedInput);
-            Map<String, DmiState> dmiStates = stateExtractor.extractStates(dmiImage, dmiMeta);
+            DmiMeta dmiMeta = MetaExtractor.extractMetadata(bufferedInput);
+            Map<String, DmiState> dmiStates = StateExtractor.extractStates(dmiImage, dmiMeta);
 
             return new Dmi(dmiName, dmiImage.getWidth(), dmiImage.getHeight(), dmiMeta, dmiStates);
         } catch (IOException e) {

src/main/java/io/github/spair/byond/dmi/MetaExtractor.java

@@ -38,7 +38,7 @@ final class MetaExtractor {
 
     private static final String MOVEMENT_SUFFIX = " (M)";
 
-    DmiMeta extractMetadata(final InputStream input) {
+    static DmiMeta extractMetadata(final InputStream input) {
         IIOMetadata metadata = readMetadata(input);
 
         String metadataFormatName = IIOMetadataFormatImpl.standardMetadataFormatName;
@@ -50,7 +50,7 @@ DmiMeta extractMetadata(final InputStream input) {
         return parseMetadataText(metadataText);
     }
 
-    private IIOMetadata readMetadata(final InputStream input) {
+    private static IIOMetadata readMetadata(final InputStream input) {
         try (ImageInputStream imageInputStream = ImageIO.createImageInputStream(input)) {
             ImageReader reader = ImageIO.getImageReadersByMIMEType(PNG_MIME).next();
 
@@ -63,7 +63,7 @@ private IIOMetadata readMetadata(final InputStream input) {
         }
     }
 
-    private DmiMeta parseMetadataText(final String metadataText) {
+    private static DmiMeta parseMetadataText(final String metadataText) {
         DmiMeta metadata = new DmiMeta();
         Matcher widthHeight = WIDTH_HEIGHT.matcher(metadataText);
 
@@ -99,7 +99,7 @@ private DmiMeta parseMetadataText(final String metadataText) {
         return metadata;
     }
 
-    private Meta parseState(final String stateText) {
+    private static Meta parseState(final String stateText) {
         Meta metaEntry = new Meta();
         Matcher stateParam = PARAM_PATTERN.matcher(stateText);
 
@@ -142,11 +142,14 @@ private Meta parseState(final String stateText) {
         return metaEntry;
     }
 
-    private boolean isValueTrue(final String value) {
+    private static boolean isValueTrue(final String value) {
         return "1".equals(value);
     }
 
-    private double[] doubleArrayFromString(final String str) {
+    private static double[] doubleArrayFromString(final String str) {
         return Arrays.stream(str.split(",")).mapToDouble(Double::parseDouble).toArray();
     }
+
+    private MetaExtractor() {
+    }
 }

src/main/java/io/github/spair/byond/dmi/StateExtractor.java

@@ -11,7 +11,7 @@
 
 final class StateExtractor {
 
-    Map<String, DmiState> extractStates(final BufferedImage dmiImage, final DmiMeta dmiMeta) {
+    static Map<String, DmiState> extractStates(final BufferedImage dmiImage, final DmiMeta dmiMeta) {
         final int dmiWidth = dmiImage.getWidth();
         final int spriteWidth = dmiMeta.getSpritesWidth();
         final int spriteHeight = dmiMeta.getSpritesHeight();
@@ -56,7 +56,7 @@ Map<String, DmiState> extractStates(final BufferedImage dmiImage, final DmiMeta
         return dmiStates;
     }
 
-    private BufferedImage cropSpriteImage(
+    private static BufferedImage cropSpriteImage(
             final BufferedImage dmiImage, final int width, final int height, final int xPos, final int yPos) {
         BufferedImage dst = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
 
@@ -67,7 +67,7 @@ private BufferedImage cropSpriteImage(
         return dst;
     }
 
-    private Map<SpriteDir, List<DmiSprite>> distributeAllSpritesInMap(final List<DmiSprite> allSprites) {
+    private static Map<SpriteDir, List<DmiSprite>> distributeAllSpritesInMap(final List<DmiSprite> allSprites) {
         Map<SpriteDir, List<DmiSprite>> spriteMap = new TreeMap<>(Comparator.comparingInt(dir -> dir.compareWeight));
 
         for (DmiSprite sprite : allSprites) {
@@ -78,4 +78,7 @@ private Map<SpriteDir, List<DmiSprite>> distributeAllSpritesInMap(final List<Dmi
 
         return spriteMap;
     }
+
+    private StateExtractor() {
+    }
 }

src/test/java/io/github/spair/byond/dmi/MetaExtractorTest.java

@@ -23,7 +23,7 @@ public void testExtractMetadata() throws Exception {
                 )
         );
 
-        DmiMeta metaToCompare = new MetaExtractor().extractMetadata(new FileInputStream(new File("src/test/resources/rollerbed_with_move.dmi")));
+        DmiMeta metaToCompare = MetaExtractor.extractMetadata(new FileInputStream(new File("src/test/resources/rollerbed_with_move.dmi")));
 
         assertEquals(expectedMeta, metaToCompare);
     }

src/test/java/io/github/spair/byond/dmi/StateExtractorTest.java

@@ -24,7 +24,7 @@ public void testExtractStates() throws Exception {
                 )
         );
 
-        Map<String, DmiState> states = new StateExtractor().extractStates(ImageIO.read(new File("src/test/resources/rollerbed_with_move.dmi")), meta);
+        Map<String, DmiState> states = StateExtractor.extractStates(ImageIO.read(new File("src/test/resources/rollerbed_with_move.dmi")), meta);
 
         assertEquals(meta.getMetas().get(0), states.get("down").getMeta());
         assertEquals(meta.getMetas().get(1), states.get("down (M)").getMeta());