Revert changes with feature and refactor together.

src/main/java/org/json/XML.java

@@ -6,11 +6,10 @@ Public Domain.
 
 import java.io.Reader;
 import java.io.StringReader;
+import java.math.BigDecimal;
+import java.math.BigInteger;
 import java.util.Iterator;
 
-import static org.json.NumberConversionUtil.potentialNumber;
-import static org.json.NumberConversionUtil.stringToNumber;
-
 
 /**
  * This provides static methods to convert an XML text into a JSONObject, and to
@@ -487,7 +486,8 @@ public class XML {
          * produced, then the value will just be a string.
          */
 
-        if (potentialNumber(string)) {
+        char initial = string.charAt(0);
+        if ((initial >= '0' && initial <= '9') || initial == '-') {
             try {
                 return stringToNumber(string);
             } catch (Exception ignore) {
@@ -496,6 +496,78 @@ public class XML {
         return string;
     }
 
+    /**
+     * direct copy of {@link JSONObject#stringToNumber(String)} to maintain Android support.
+     */
+    private static Number stringToNumber(final String val) throws NumberFormatException {
+        char initial = val.charAt(0);
+        if ((initial >= '0' && initial <= '9') || initial == '-') {
+            // decimal representation
+            if (isDecimalNotation(val)) {
+                // Use a BigDecimal all the time so we keep the original
+                // representation. BigDecimal doesn't support -0.0, ensure we
+                // keep that by forcing a decimal.
+                try {
+                    BigDecimal bd = new BigDecimal(val);
+                    if(initial == '-' && BigDecimal.ZERO.compareTo(bd)==0) {
+                        return Double.valueOf(-0.0);
+                    }
+                    return bd;
+                } catch (NumberFormatException retryAsDouble) {
+                    // this is to support "Hex Floats" like this: 0x1.0P-1074
+                    try {
+                        Double d = Double.valueOf(val);
+                        if(d.isNaN() || d.isInfinite()) {
+                            throw new NumberFormatException("val ["+val+"] is not a valid number.");
+                        }
+                        return d;
+                    } catch (NumberFormatException ignore) {
+                        throw new NumberFormatException("val ["+val+"] is not a valid number.");
+                    }
+                }
+            }
+            // block items like 00 01 etc. Java number parsers treat these as Octal.
+            if(initial == '0' && val.length() > 1) {
+                char at1 = val.charAt(1);
+                if(at1 >= '0' && at1 <= '9') {
+                    throw new NumberFormatException("val ["+val+"] is not a valid number.");
+                }
+            } else if (initial == '-' && val.length() > 2) {
+                char at1 = val.charAt(1);
+                char at2 = val.charAt(2);
+                if(at1 == '0' && at2 >= '0' && at2 <= '9') {
+                    throw new NumberFormatException("val ["+val+"] is not a valid number.");
+                }
+            }
+            // integer representation.
+            // This will narrow any values to the smallest reasonable Object representation
+            // (Integer, Long, or BigInteger)
+
+            // BigInteger down conversion: We use a similar bitLength compare as
+            // BigInteger#intValueExact uses. Increases GC, but objects hold
+            // only what they need. i.e. Less runtime overhead if the value is
+            // long lived.
+            BigInteger bi = new BigInteger(val);
+            if(bi.bitLength() <= 31){
+                return Integer.valueOf(bi.intValue());
+            }
+            if(bi.bitLength() <= 63){
+                return Long.valueOf(bi.longValue());
+            }
+            return bi;
+        }
+        throw new NumberFormatException("val ["+val+"] is not a valid number.");
+    }
+
+    /**
+     * direct copy of {@link JSONObject#isDecimalNotation(String)} to maintain Android support.
+     */
+    private static boolean isDecimalNotation(final String val) {
+        return val.indexOf('.') > -1 || val.indexOf('e') > -1
+                || val.indexOf('E') > -1 || "-0".equals(val);
+    }
+
+
     /**
      * Convert a well-formed (but not necessarily valid) XML string into a
      * JSONObject. Some information may be lost in this transformation because