[Java]: Introduced HEADER_SIZE constant to repeating groups stub.

Author: mjpt777

main/java/uk/co/real_logic/sbe/generation/java/JavaGenerator.java

@@ -205,15 +205,17 @@ private void generateGroupClassHeader(final StringBuilder sb,
  "\n" +
  indent + "public static class %1$s implements Iterable<%1$s>, java.util.Iterator<%1$s>\n" +
  indent + "{\n" +
- indent + " private final %2$s dimensions = new %2$s();\n" +
- indent + " private %3$s parentMessage;\n" +
+ indent + " private static final int HEADER_SIZE = %2$d;\n" +
+ indent + " private final %3$s dimensions = new %3$s();\n" +
+ indent + " private %4$s parentMessage;\n" +
  indent + " private DirectBuffer buffer;\n" +
  indent + " private int blockLength;\n" +
  indent + " private int actingVersion;\n" +
  indent + " private int count;\n" +
  indent + " private int index;\n" +
  indent + " private int offset;\n\n",
  formatClassName(groupName),
+ dimensionHeaderSize,
  dimensionsClassName,
  parentMessageClassName
  ));
@@ -228,7 +230,7 @@ private void generateGroupClassHeader(final StringBuilder sb,
  indent + " blockLength = dimensions.blockLength();\n" +
  indent + " this.actingVersion = actingVersion;\n" +
  indent + " index = -1;\n" +
- indent + " parentMessage.limit(parentMessage.limit() + headerSize());\n" +
+ indent + " parentMessage.limit(parentMessage.limit() + HEADER_SIZE);\n" +
  indent + " }\n\n",
  parentMessageClassName
  ));
@@ -248,7 +250,7 @@ private void generateGroupClassHeader(final StringBuilder sb,
  indent + " index = -1;\n" +
  indent + " this.count = count;\n" +
  indent + " blockLength = %4$d;\n" +
- indent + " parentMessage.limit(parentMessage.limit() + headerSize());\n" +
+ indent + " parentMessage.limit(parentMessage.limit() + HEADER_SIZE);\n" +
  indent + " }\n\n",
  parentMessageClassName,
  javaTypeForNumInGroup,
@@ -259,9 +261,8 @@ private void generateGroupClassHeader(final StringBuilder sb,
  sb.append(String.format(
  indent + " public static int headerSize()\n" +
  indent + " {\n" +
- indent + " return %d;\n" +
- indent + " }\n\n",
- dimensionHeaderSize
+ indent + " return HEADER_SIZE;\n" +
+ indent + " }\n\n"
  ));
 
  sb.append(String.format(