private String buildJSONFromFields(Collection<SearchHitField> values) { JsonFactory nodeFactory = new JsonFactory(); try { ByteArrayOutputStream stream = new ByteArrayOutputStream(); JsonGenerator generator = nodeFactory.createGenerator(stream, JsonEncoding.UTF8); generator.writeStartObject(); for (SearchHitField value : values) { if (value.getValues().size() > 1) { generator.writeArrayFieldStart(value.getName()); for (Object val : value.getValues()) { generator.writeObject(val); } generator.writeEndArray(); } else { generator.writeObjectField(value.getName(), value.getValue()); } } generator.writeEndObject(); generator.flush(); return new String(stream.toByteArray(), Charset.forName("UTF-8")); } catch (IOException e) { return null; } }