Clean up code in src/main/java

Infer generic parameters for Map, List, etc.
Cease use of deprecated Java API.
Suppress "unchecked", "hiding" warnings where appropriate.
Add missing serialVersionUID where necessary.
Use getRenderSettings()/getParseSettings() instead of deprecated access.
Remove unused class members.
Remove unused imports.

src/main/java/liqp/Insertion.java

@@ -1,8 +1,6 @@
 package liqp;
 
-import java.util.HashMap;
 import java.util.Locale;
-import java.util.Map;
 
 import liqp.nodes.LNode;
 

src/main/java/liqp/LValue.java

@@ -1,9 +1,9 @@
 package liqp;
 
-import static java.math.BigDecimal.ROUND_UNNECESSARY;
 import static liqp.filters.date.Parser.getZonedDateTimeFromTemporalAccessor;
 
 import java.math.BigDecimal;
+import java.math.RoundingMode;
 import java.time.ZonedDateTime;
 import java.time.format.DateTimeFormatter;
 import java.time.temporal.ChronoField;
@@ -219,9 +219,9 @@ public static boolean isTemporal(Object value){
      * @param value
      * @return
      */
-    protected Object[] mapAsArray(Map value) {
+    protected Object[] mapAsArray(Map<?,?> value) {
         List<Object[]> keyValuePairs = new ArrayList<>();
-        for (Map.Entry<Object, Object> entry : ((Map<Object, Object>) value).entrySet()) {
+        for (Map.Entry<?, ?> entry : value.entrySet()) {
             keyValuePairs.add(new Object[]{entry.getKey(), entry.getValue()});
         }
         return keyValuePairs.toArray();
@@ -279,7 +279,7 @@ public Number asNumber(Object value) throws NumberFormatException {
     // mimic ruby's `BigDecimal.to_f` with standard java capabilities
     // same time provide expected out for java.math.BigDecimal
     public static String asFormattedNumber(BigDecimal bd) {
-        return bd.setScale(Math.max(1, bd.stripTrailingZeros().scale()), ROUND_UNNECESSARY).toPlainString();
+        return bd.setScale(Math.max(1, bd.stripTrailingZeros().scale()), RoundingMode.UNNECESSARY).toPlainString();
     }
 
     /**
@@ -438,7 +438,7 @@ public boolean isFalsy(Object value, TemplateContext context) {
         if (this.isArray(value) && this.asArray(value, context).length == 0)
             return true;
 
-        if ((value instanceof Map) && ((Map) value).isEmpty())
+        if ((value instanceof Map) && ((Map<?,?>) value).isEmpty())
             return true;
 
         return false;
@@ -456,8 +456,8 @@ public boolean isMap(Object value) {
         return value != null && (value instanceof Map);
     }
 
+    @SuppressWarnings("unchecked")
     public Map<String, Object> asMap(Object value) {
-
         return (Map<String, Object>)value;
     }
 }

src/main/java/liqp/ParseSettings.java

@@ -10,6 +10,7 @@
 import liqp.filters.Filters;
 import liqp.parser.Flavor;
 
+@SuppressWarnings("hiding")
 public class ParseSettings {
     public static final Flavor DEFAULT_FLAVOR = Flavor.LIQUID;
     public static final ParseSettings DEFAULT = DEFAULT_FLAVOR.defaultParseSettings();

src/main/java/liqp/ProtectionSettings.java

@@ -2,6 +2,7 @@
 
 import liqp.exceptions.ExceededMaxIterationsException;
 
+@SuppressWarnings("hiding")
 public class ProtectionSettings {
     public static final ProtectionSettings DEFAULT = new ProtectionSettings.Builder().build();
 

src/main/java/liqp/RenderSettings.java

@@ -10,6 +10,7 @@
 
 import liqp.parser.LiquidSupport;
 
+@SuppressWarnings("hiding")
 public class RenderSettings {
     public static final Locale DEFAULT_LOCALE = Locale.ENGLISH;
 
@@ -102,7 +103,7 @@ public Builder withLocale(Locale locale){
          * that does not have own timezone information.
          * May be null, so the timezone pattern will be omitted in formatted strings.
          * @param defaultTimeZone - value or <code>null<code/>
-         * @return
+         * @return This builder.
          */
         public Builder withDefaultTimeZone(ZoneId defaultTimeZone) {
             this.defaultTimeZone = defaultTimeZone;

src/main/java/liqp/TemplateContext.java

@@ -8,10 +8,10 @@
 import java.util.Map;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
+
 import liqp.RenderTransformer.ObjectAppender;
-import liqp.parser.LiquidSupport;
 import liqp.filters.Filters;
-import liqp.parser.Flavor;
+import liqp.parser.LiquidSupport;
 
 public class TemplateContext {
 
@@ -180,9 +180,7 @@ public Map<String, Object> getEnvironmentMap() {
         return environmentMap;
     }
 
-    /**
-     * The registry is
-     */
+    @SuppressWarnings("unchecked")
     public <T extends Map<String, ?>> T getRegistry(String registryName) {
         if (parent != null) {
             return parent.getRegistry(registryName);

src/main/java/liqp/TemplateParser.java

@@ -76,6 +76,7 @@ public Builder withProtectionSettings(ProtectionSettings s) {
             return this;
         }
 
+        @SuppressWarnings("hiding")
         public Builder withErrorMode(ErrorMode errorMode) {
             this.errorMode = errorMode;
             return this;

src/main/java/liqp/blocks/Block.java

@@ -1,7 +1,6 @@
 package liqp.blocks;
 
 import liqp.Insertion;
-import liqp.ParseSettings;
 
 public abstract class Block extends Insertion {
     /**

src/main/java/liqp/exceptions/ExceededMaxIterationsException.java

@@ -1,6 +1,7 @@
 package liqp.exceptions;
 
 public class ExceededMaxIterationsException extends RuntimeException {
+    private static final long serialVersionUID = -2177965025182952056L;
 
     public ExceededMaxIterationsException(int maxIterations) {
         super("exceeded maxIterations: " + maxIterations);

src/main/java/liqp/exceptions/LiquidException.java

@@ -7,6 +7,7 @@
 import java.util.List;
 
 public class LiquidException extends RuntimeException {
+  private static final long serialVersionUID = -7720091243157735323L;
 
   public final int line;
   public final int charPositionInLine;

src/main/java/liqp/exceptions/VariableNotExistException.java

@@ -1,7 +1,7 @@
 package liqp.exceptions;
 
-
 public class VariableNotExistException extends RuntimeException {
+    private static final long serialVersionUID = -2726673309959828365L;
     private final String variableName;
 
     public VariableNotExistException(String variableName) {

src/main/java/liqp/filters/Absolute_Url.java

@@ -66,7 +66,7 @@ public Object apply(Object value, TemplateContext context, Object... params) {
         }
     }
 
-    public static String convertUnicodeURLToAscii(String url) throws URISyntaxException {
+    public static String convertUnicodeURLToAscii(@SuppressWarnings("hiding") String url) throws URISyntaxException {
         if(url != null) {
             url = url.trim();
             URI uri = new URI(url);

src/main/java/liqp/filters/Date.java

@@ -8,7 +8,6 @@
 import ua.co.k.strftime.StrftimeFormatter;
 
 import java.time.Instant;
-import java.time.ZoneId;
 import java.time.ZonedDateTime;
 import java.util.Locale;
 
@@ -22,7 +21,7 @@ protected Date() {
         super();
     }
 
-    protected Date(CustomDateFormatSupport typeSupport) {
+    protected Date(CustomDateFormatSupport<?> typeSupport) {
         super();
         CustomDateFormatRegistry.add(typeSupport);
     }
@@ -89,7 +88,7 @@ public static void removeDatePattern(String pattern) {
         datePatterns.remove(pattern);
     }
 
-    public static Filter withCustomDateType(CustomDateFormatSupport typeSupport) {
+    public static Filter withCustomDateType(CustomDateFormatSupport<?> typeSupport) {
         return new Date(typeSupport);
     }
 }

src/main/java/liqp/filters/Filter.java

@@ -1,17 +1,10 @@
 package liqp.filters;
 
-import static liqp.ParseSettings.DEFAULT_FLAVOR;
-
 import java.util.Arrays;
-import java.util.HashMap;
 import java.util.Locale;
-import java.util.Map;
 
 import liqp.LValue;
-import liqp.ParseSettings;
 import liqp.TemplateContext;
-import liqp.TemplateParser;
-import liqp.parser.Flavor;
 
 /**
  * Output markup takes filters. Filters are simple methods. The first parameter is always the output of

src/main/java/liqp/filters/Map.java

@@ -1,12 +1,12 @@
 package liqp.filters;
 
+import java.util.ArrayList;
+import java.util.List;
+
 import liqp.TemplateContext;
 import liqp.parser.Inspectable;
 import liqp.parser.LiquidSupport;
 
-import java.util.ArrayList;
-import java.util.List;
-
 public class Map extends Filter {
 
     /*
@@ -29,12 +29,12 @@ public Object apply(Object value, TemplateContext context, Object... params) {
 
         for (Object obj : array) {
 
-            java.util.Map map;
+            java.util.Map<?,?> map;
             if (value instanceof Inspectable) {
                 LiquidSupport evaluated = context.evaluate(value);
                 map = evaluated.toLiquid();
             } else {
-                map = (java.util.Map) obj;
+                map = (java.util.Map<?,?>) obj;
             }
 
             Object val = map.get(key);

src/main/java/liqp/filters/Modulo.java

@@ -1,10 +1,9 @@
 package liqp.filters;
 
-import liqp.Template;
-import liqp.TemplateContext;
-
 import java.math.BigDecimal;
 
+import liqp.TemplateContext;
+
 public class Modulo extends Filter {
 
     /*

src/main/java/liqp/filters/Sort.java

@@ -56,7 +56,7 @@ public Object apply(Object value, TemplateContext context, Object... params) {
 
         array = super.asArray(value, context);
 
-        List<Comparable> list = asComparableList(context, array, property);
+        List<Comparable<Object>> list = asComparableList(context, array, property);
 
         Collections.sort(list);
 
@@ -107,9 +107,10 @@ public String toString() {
         }
     }
 
-    private List<Comparable> asComparableList(TemplateContext context, Object[] array, String property) {
+    @SuppressWarnings("unchecked")
+    private List<Comparable<Object>> asComparableList(TemplateContext context, Object[] array, String property) {
 
-        List<Comparable> list = new ArrayList<Comparable>();
+        List<Comparable<Object>> list = new ArrayList<Comparable<Object>>();
 
         for (Object obj : array) {
 
@@ -119,29 +120,33 @@ private List<Comparable> asComparableList(TemplateContext context, Object[] arra
                 obj = evaluated.toLiquid();
             }
             if (obj instanceof java.util.Map && property != null) {
-                list.add(new SortableMap((java.util.Map<String, Comparable>) obj, property));
+                list.add(new SortableMap((java.util.Map<String, Comparable<Object>>) obj, property));
             } else {
-                list.add((Comparable) obj);
+                list.add((Comparable<Object>) obj);
             }
         }
 
         return list;
     }
 
-    static class SortableMap extends HashMap<String, Comparable> implements Comparable<SortableMap> {
-
+    static class SortableMap extends HashMap<String, Comparable<Object>> implements Comparable<Object> {
+        private static final long serialVersionUID = -6480701533195197967L;
         final String property;
 
-        SortableMap(java.util.Map<String, Comparable> map, String property) {
+        SortableMap(java.util.Map<String, Comparable<Object>> map, String property) {
             super.putAll(map);
             this.property = property;
         }
 
         @Override
-        public int compareTo(SortableMap that) {
-
-            Comparable thisValue = this.get(property);
-            Comparable thatValue = that.get(property);
+        public int compareTo(Object that) {
+            Comparable<Object> thisValue = this.get(property);
+            Object thatValue;
+            if(that instanceof SortableMap)  {
+                thatValue = ((SortableMap)that).get(property);
+            } else {
+                thatValue = that;
+            }
 
             if (thisValue == null || thatValue == null) {
                 throw new RuntimeException("Liquid error: comparison of Hash with Hash failed");
@@ -154,7 +159,7 @@ public int compareTo(SortableMap that) {
         public String toString() {
             StringBuilder builder = new StringBuilder();
 
-            for (java.util.Map.Entry entry : super.entrySet()) {
+            for (java.util.Map.Entry<?,?> entry : super.entrySet()) {
                 builder.append(entry.getKey()).append(entry.getValue());
             }
 

src/main/java/liqp/filters/Sort_Natural.java

@@ -16,7 +16,7 @@ public Object apply(Object value, TemplateContext context, Object... params) {
         Object[] array = super.asArray(value, context);
         List<Object> list = new ArrayList<Object>(Arrays.asList(array));
 
-        Collections.sort(list, new Comparator() {
+        Collections.sort(list, new Comparator<Object>() {
             @Override
             public int compare(Object o1, Object o2) {
                 return String.valueOf(o1).compareToIgnoreCase(String.valueOf(o2));

src/main/java/liqp/filters/Times.java

@@ -2,8 +2,6 @@
 
 import java.math.BigDecimal;
 
-import static java.math.BigDecimal.ROUND_UNNECESSARY;
-
 public class Times extends Filter {
 
     /*

src/main/java/liqp/filters/Where.java

@@ -5,7 +5,6 @@
 import liqp.filters.where.LiquidWhereImpl;
 import liqp.filters.where.PropertyResolverHelper;
 import liqp.filters.where.WhereImpl;
-import liqp.parser.Flavor;
 
 /**
  * There are two different implementations of this filter in ruby.

src/main/java/liqp/filters/date/CustomDateFormatRegistry.java

@@ -13,10 +13,11 @@ public class CustomDateFormatRegistry {
     // might be better storage for this will be tree,
     // so the subtypes will be properly handled
     // and parent type will not override child's one
-    private static final List<CustomDateFormatSupport> supportedTypes = new ArrayList<>();
+    private static final List<CustomDateFormatSupport<Object>> supportedTypes = new ArrayList<>();
 
-    public static void add(CustomDateFormatSupport supportThis) {
-        supportedTypes.add(0, supportThis);
+    @SuppressWarnings("unchecked")
+    public static void add(CustomDateFormatSupport<?> supportThis) {
+        supportedTypes.add(0, (CustomDateFormatSupport<Object>)supportThis);
     }
 
 
@@ -25,7 +26,7 @@ public static boolean isRegistered(CustomDateFormatSupport<?> typeSupport) {
     }
 
     public static boolean isCustomDateType(Object value) {
-        for (CustomDateFormatSupport el: supportedTypes) {
+        for (CustomDateFormatSupport<?> el: supportedTypes) {
             if (el.support(value)) {
                 return true;
             }
@@ -34,7 +35,7 @@ public static boolean isCustomDateType(Object value) {
     }
 
     public static ZonedDateTime getFromCustomType(Object value) {
-        for (CustomDateFormatSupport el: supportedTypes) {
+        for (CustomDateFormatSupport<Object> el: supportedTypes) {
             if (el.support(value)) {
                 return el.getValue(value);
             }