fix exception handling

Author: pjfanning

src/main/java/com/fasterxml/jackson/core/io/BigDecimalParser.java

@@ -40,11 +40,18 @@ private BigDecimalParser() {}
      * @throws NumberFormatException
      */
     public static BigDecimal parse(String valueStr) {
-        if (valueStr.length() < 500) {
-            return new BigDecimal(valueStr);
+        try {
+            if (valueStr.length() < 500) {
+                return new BigDecimal(valueStr);
+            }
+            // workaround https://github.com/FasterXML/jackson-databind/issues/4694
+            return JavaBigDecimalParser.parseBigDecimal(valueStr);
+
+            // 20-Aug-2022, tatu: Although "new BigDecimal(...)" only throws NumberFormatException
+            //    operations by "parseBigDecimal()" can throw "ArithmeticException", so handle both:
+        } catch (ArithmeticException | NumberFormatException e) {
+            throw _parseFailure(e, valueStr);
         }
-        // workaround https://github.com/FasterXML/jackson-databind/issues/4694
-        return JavaBigDecimalParser.parseBigDecimal(valueStr);
     }
 
     /**
@@ -68,7 +75,7 @@ public static BigDecimal parse(final char[] chars, final int off, final int len)
         // 20-Aug-2022, tatu: Although "new BigDecimal(...)" only throws NumberFormatException
         //    operations by "parseBigDecimal()" can throw "ArithmeticException", so handle both:
         } catch (ArithmeticException | NumberFormatException e) {
-            throw _parseFailure(e, new String(chars, off, len));
+            throw _parseFailure(e, chars, off, len);
         }
     }
 
@@ -118,7 +125,8 @@ public static BigDecimal parseWithFastParser(final String valueStr) {
      */
     public static BigDecimal parseWithFastParser(final char[] ch, final int off, final int len) {
         try {
-            return JavaBigDecimalParser.parseBigDecimal(ch, off, len);
+            // workaround https://github.com/FasterXML/jackson-databind/issues/4694
+            return JavaBigDecimalParser.parseBigDecimal(new String(ch, off, len));
         } catch (ArithmeticException | NumberFormatException e) {
             throw _parseFailure(e, new String(ch, off, len));
         }
@@ -131,11 +139,23 @@ private static NumberFormatException _parseFailure(Exception e, String fullValue
             desc = "Not a valid number representation";
         }
         String valueToReport = _getValueDesc(fullValue);
-        return new NumberFormatException("Value " + valueToReport
-                + " can not be deserialized as `java.math.BigDecimal`, reason: " + desc);
+        return new NumberFormatException(_generateExceptionMessage(valueToReport, desc));
+    }
+
+    private static NumberFormatException _parseFailure(final Exception e,
+                                                       final char[] array,
+                                                       final int offset,
+                                                       final int len) {
+        String desc = e.getMessage();
+        // 05-Feb-2021, tatu: Alas, JDK mostly has null message so:
+        if (desc == null) {
+            desc = "Not a valid number representation";
+        }
+        String valueToReport = _getValueDesc(array, offset, len);
+        return new NumberFormatException(_generateExceptionMessage(valueToReport, desc));
     }
 
-    private static String _getValueDesc(String fullValue) {
+    private static String _getValueDesc(final String fullValue) {
         final int len = fullValue.length();
         if (len <= MAX_CHARS_TO_REPORT) {
             return String.format("\"%s\"", fullValue);
@@ -145,4 +165,18 @@ private static String _getValueDesc(String fullValue) {
                 MAX_CHARS_TO_REPORT, len);
     }
 
+    private static String _getValueDesc(final char[] array, final int offset, final int len) {
+        if (len <= MAX_CHARS_TO_REPORT) {
+            return String.format("\"%s\"", new String(array, offset, len));
+        }
+        return String.format("\"%s\" (truncated to %d chars (from %d))",
+            new String(array, offset, MAX_CHARS_TO_REPORT),
+            MAX_CHARS_TO_REPORT, len);
+    }
+
+    private static String _generateExceptionMessage(final String valueToReport, final String desc) {
+        return String.format("Value %s cannot be deserialized as `java.math.BigDecimal`, reason:  %s" ,
+            valueToReport, desc);
+    }
+
 }

src/test/java/com/fasterxml/jackson/core/io/BigDecimalParserTest.java

@@ -58,8 +58,10 @@ void issueDatabind4694() {
         final BigDecimal expected = new BigDecimal(str);
         assertEquals(expected, JavaBigDecimalParser.parseBigDecimal(str));
         assertEquals(expected, BigDecimalParser.parse(str));
+        assertEquals(expected, BigDecimalParser.parseWithFastParser(str));
         final char[] arr = str.toCharArray();
         assertEquals(expected, BigDecimalParser.parse(arr, 0, arr.length));
+        assertEquals(expected, BigDecimalParser.parseWithFastParser(arr, 0, arr.length));
     }
 
     static String genLongInvalidString() {