[Java] Added sinceVersion metadata accessor methods to generated decoders.

Author: mjpt777

sbe-tool/src/main/java/uk/co/real_logic/sbe/generation/java/JavaGenerator.java

@@ -572,6 +572,15 @@ private static CharSequence generateGroupDecoderProperty(final String groupName,
             formatPropertyName(groupName),
             token.id()));
 
+        sb.append(String.format(
+            "\n" +
+            indent + "    public static int %sSinceVersion()\n" +
+            indent + "    {\n" +
+            indent + "        return %d;\n" +
+            indent + "    }\n",
+            formatPropertyName(groupName),
+            token.version()));
+
         sb.append(String.format(
             "\n" +
             indent + "    public %1$s %2$s()\n" +
@@ -633,6 +642,8 @@ private CharSequence generateDecoderVarData(final List<Token> tokens, final Stri
             }
 
             generateFieldIdMethod(sb, token, indent);
+            generateFieldSinceVersionMethod(sb, token, indent);
+
             final String characterEncoding = tokens.get(i + 3).encoding().characterEncoding();
             generateCharacterEncodingMethod(sb, token.name(), characterEncoding, indent);
             generateFieldMetaAttributeMethod(sb, token, indent);
@@ -1946,6 +1957,7 @@ private CharSequence generateDecoderFields(final List<Token> tokens, final Strin
                 final String typeName = decoderName(formatClassName(typeToken.name()));
 
                 generateFieldIdMethod(sb, fieldToken, indent);
+                generateFieldSinceVersionMethod(sb, fieldToken, indent);
                 generateFieldMetaAttributeMethod(sb, fieldToken, indent);
 
                 switch (typeToken.signal())
@@ -2001,6 +2013,18 @@ private static void generateFieldIdMethod(final StringBuilder sb, final Token to
             token.id()));
     }
 
+    private static void generateFieldSinceVersionMethod(final StringBuilder sb, final Token token, final String indent)
+    {
+        sb.append(String.format(
+            "\n" +
+                indent + "    public static int %sSinceVersion()\n" +
+                indent + "    {\n" +
+                indent + "        return %d;\n" +
+                indent + "    }\n",
+            formatPropertyName(token.name()),
+            token.version()));
+    }
+
     private static void generateFieldMetaAttributeMethod(final StringBuilder sb, final Token token, final String indent)
     {
         final Encoding encoding = token.encoding();