Missing Hierarchy: JSONArray-JSONObject-JSONString 'similar' method code smell fix

Author: alwinsanil

src/main/java/org/json/JSONArray.java

@@ -60,7 +60,7 @@
  * @author JSON.org
  * @version 2016-08/15
  */
-public class JSONArray implements Iterable<Object> {
+public class JSONArray implements Iterable<Object>, JSONSimilar {
 
     /**
      * The arrayList where the JSONArray's properties are kept.
@@ -1643,44 +1643,21 @@ public Object remove(int index) {
     /**
      * Determine if two JSONArrays are similar.
      * They must contain similar sequences.
-     *
      * @param other The other JSONArray
      * @return true if they are equal
      */
+    @Override
     public boolean similar(Object other) {
         if (!(other instanceof JSONArray)) {
             return false;
         }
+        JSONArray otherArray = (JSONArray)other;
         int len = this.length();
-        if (len != ((JSONArray)other).length()) {
+        if (len != otherArray.length()) {
             return false;
         }
         for (int i = 0; i < len; i += 1) {
-            Object valueThis = this.myArrayList.get(i);
-            Object valueOther = ((JSONArray)other).myArrayList.get(i);
-            if(valueThis == valueOther) {
-            	continue;
-            }
-            if(valueThis == null) {
-            	return false;
-            }
-            if (valueThis instanceof JSONObject) {
-                if (!((JSONObject)valueThis).similar(valueOther)) {
-                    return false;
-                }
-            } else if (valueThis instanceof JSONArray) {
-                if (!((JSONArray)valueThis).similar(valueOther)) {
-                    return false;
-                }
-            } else if (valueThis instanceof Number && valueOther instanceof Number) {
-                if (!JSONObject.isNumberSimilar((Number)valueThis, (Number)valueOther)) {
-                	return false;
-                }
-            } else if (valueThis instanceof JSONString && valueOther instanceof JSONString) {
-                if (!((JSONString) valueThis).toJSONString().equals(((JSONString) valueOther).toJSONString())) {
-                    return false;
-                }
-            } else if (!valueThis.equals(valueOther)) {
+            if (!JSONSimilar.compare(this.myArrayList.get(i), otherArray.myArrayList.get(i))) {
                 return false;
             }
         }

src/main/java/org/json/JSONObject.java

@@ -71,7 +71,7 @@
  * @author JSON.org
  * @version 2016-08-15
  */
-public class JSONObject {
+public class JSONObject implements JSONSimilar {
     /**
      * JSONObject.NULL is equivalent to the value that JavaScript calls null,
      * whilst Java's null is equivalent to the value that JavaScript calls
@@ -2358,45 +2358,21 @@ public Object remove(String key) {
      * Determine if two JSONObjects are similar.
      * They must contain the same set of names which must be associated with
      * similar values.
-     *
      * @param other The other JSONObject
      * @return true if they are equal
      */
+    @Override
     public boolean similar(Object other) {
         try {
             if (!(other instanceof JSONObject)) {
                 return false;
             }
-            if (!this.keySet().equals(((JSONObject)other).keySet())) {
+            JSONObject otherObj = (JSONObject)other;
+            if (!this.keySet().equals(otherObj.keySet())) {
                 return false;
             }
-            for (final Entry<String,?> entry : this.entrySet()) {
-                String name = entry.getKey();
-                Object valueThis = entry.getValue();
-                Object valueOther = ((JSONObject)other).get(name);
-                if(valueThis == valueOther) {
-                	continue;
-                }
-                if(valueThis == null) {
-                	return false;
-                }
-                if (valueThis instanceof JSONObject) {
-                    if (!((JSONObject)valueThis).similar(valueOther)) {
-                        return false;
-                    }
-                } else if (valueThis instanceof JSONArray) {
-                    if (!((JSONArray)valueThis).similar(valueOther)) {
-                        return false;
-                    }
-                } else if (valueThis instanceof Number && valueOther instanceof Number) {
-                    if (!isNumberSimilar((Number)valueThis, (Number)valueOther)) {
-                    	return false;
-                    }
-                } else if (valueThis instanceof JSONString && valueOther instanceof JSONString) {
-                    if (!((JSONString) valueThis).toJSONString().equals(((JSONString) valueOther).toJSONString())) {
-                    	return false;
-                    }
-                } else if (!valueThis.equals(valueOther)) {
+            for (Map.Entry<String,?> entry : this.entrySet()) {
+                if (!JSONSimilar.compare(entry.getValue(), otherObj.get(entry.getKey()))) {
                     return false;
                 }
             }

src/main/java/org/json/JSONSimilar.java

@@ -0,0 +1,33 @@
+package org.json;
+
+/**
+ * Interface for comparing JSON entities for semantic similarity.
+ * @author JSON.org
+ * @version 2023-07-20
+ */
+public interface JSONSimilar {
+    /**
+     * Determine if this JSON entity is similar to another object.
+     * @param other The object to compare with
+     * @return true if they are semantically similar
+     */
+    boolean similar(Object other);
+
+    /**
+     * Helper method to compare two arbitrary values according to JSON similarity rules.
+     * @param a First value to compare
+     * @param b Second value to compare
+     * @return true if values are semantically similar
+     */
+    static boolean compare(Object a, Object b) {
+        if (a == b) return true;
+        if (a == null || b == null) return false;
+        if (a instanceof JSONSimilar) {
+            return ((JSONSimilar)a).similar(b);
+        }
+        if (a instanceof Number && b instanceof Number) {
+            return JSONSimilarUtils.areNumbersSimilar((Number)a, (Number)b);
+        }
+        return a.equals(b);
+    }
+}

src/main/java/org/json/JSONSimilarUtils.java

@@ -0,0 +1,27 @@
+package org.json;
+
+/**
+ * Utility class for JSON similarity comparisons.
+ * @author JSON.org
+ * @version 2023-07-20
+ */
+public final class JSONSimilarUtils {
+    private static final double FLOATING_POINT_TOLERANCE = 0.000001d;
+
+    /**
+     * Compare two numbers for JSON similarity with proper handling of different numeric types.
+     * @param a First number to compare
+     * @param b Second number to compare
+     * @return true if numbers are semantically equivalent in JSON context
+     */
+    static boolean areNumbersSimilar(Number a, Number b) {
+        if (a.equals(b)) {
+            return true;
+        }
+        if (a instanceof Double || a instanceof Float ||
+                b instanceof Double || b instanceof Float) {
+            return Math.abs(a.doubleValue() - b.doubleValue()) < FLOATING_POINT_TOLERANCE;
+        }
+        return a.longValue() == b.longValue();
+    }
+}

src/main/java/org/json/JSONString.java

@@ -12,12 +12,25 @@
  * <code>toJSONString</code> method will be used instead of the default behavior
  * of using the Object's <code>toString()</code> method and quoting the result.
  */
-public interface JSONString {
+public interface JSONString extends JSONSimilar {
     /**
      * The <code>toJSONString</code> method allows a class to produce its own JSON
      * serialization.
      *
      * @return A strictly syntactically correct JSON text.
      */
     public String toJSONString();
+
+    /**
+     * Determine if two JSONStrings are similar by comparing their serialized forms.
+     * @param other The other JSONString
+     * @return true if their JSON representations are equal
+     */
+    @Override
+    default boolean similar(Object other) {
+        if (!(other instanceof JSONString)) {
+            return false;
+        }
+        return this.toJSONString().equals(((JSONString)other).toJSONString());
+    }
 }