altoslib: NumberFormat can't be shared between parsers

AltosJson uses NumberFormat to ensure locale-independent parsing of
values. However, NumberFormat appears to have some internal state
which means that each thread needs to have an independent NumberFormat
object. Create one for each parser as needed.

Signed-off-by: Keith Packard <keithp@keithp.com>

diff --git a/altoslib/AltosJson.java b/altoslib/AltosJson.java
index 190d263363dd680898d80a173311c9ebb7e7a1c5..b981c36513939a7de503de3ce111473bf2b13a4e 100644 (file)
--- a/altoslib/AltosJson.java
+++ b/altoslib/AltosJson.java
@@ -63,18 +63,22 @@ class JsonUtil {
                        result.append("\t");
                return result;
        }
-       static NumberFormat get_nf_json() {
-               DecimalFormat nf = (DecimalFormat) NumberFormat.getNumberInstance(Locale.ROOT);
-               nf.setParseIntegerOnly(false);
-               nf.setGroupingUsed(false);
-               nf.setMaximumFractionDigits(17);
-               nf.setMinimumFractionDigits(0);
-               nf.setMinimumIntegerDigits(1);
-               nf.setDecimalSeparatorAlwaysShown(false);
-               return nf;
-       }
-
-       static NumberFormat nf_json = get_nf_json();
+
+       NumberFormat _nf_json;
+
+       NumberFormat nf_json() {
+               if (_nf_json == null) {
+                       DecimalFormat nf = (DecimalFormat) NumberFormat.getNumberInstance(Locale.ROOT);
+                       nf.setParseIntegerOnly(false);
+                       nf.setGroupingUsed(false);
+                       nf.setMaximumFractionDigits(17);
+                       nf.setMinimumFractionDigits(0);
+                       nf.setMinimumIntegerDigits(1);
+                       nf.setDecimalSeparatorAlwaysShown(false);
+                       _nf_json = nf;
+               }
+               return _nf_json;
+       }
 }
 
 class JsonHash extends JsonUtil {
@@ -372,7 +376,7 @@ class JsonLexer extends JsonUtil {
                                        String dstr = dbuf.toString();
                                        double dval;
                                        try {
-                                               dval = nf_json.parse(dstr).doubleValue();
+                                               dval = nf_json().parse(dstr).doubleValue();
                                        } catch (ParseException pe) {
                                                return new JsonToken(JsonToken._error, dstr);
                                        }
@@ -612,7 +616,7 @@ public class AltosJson extends JsonUtil {
                        } else if (Double.isNaN(d_number)) {
                                result.append("NaN");
                        } else {
-                               String dval = nf_json.format(d_number);
+                               String dval = nf_json().format(d_number);
                                if (dval.equals("-0"))
                                        dval = "0";
                                result.append(dval);