public static String formulateJsonForListRegions(Set<Region<?, ?>> regions, String fieldName) { HeapDataOutputStream outputStream = new HeapDataOutputStream(com.gemstone.gemfire.internal.Version.CURRENT); try { JsonGenerator generator = enableDisableJSONGeneratorFeature( getObjectMapper().getFactory().createGenerator(outputStream, JsonEncoding.UTF8)); generator.writeStartObject(); generator.writeFieldName(fieldName); JsonWriter.writeRegionSetAsJson(generator, regions); generator.writeEndObject(); generator.close(); return new String(outputStream.toByteArray()); } catch (IOException e) { throw new RuntimeException(e.getMessage()); } finally { outputStream.close(); } }