public class JsonUtil { private final Pattern patternKey = Pattern.compile("^([a-zA-Z0-9_\\-\\:\\s]+).*"); private final Pattern patternIndex = Pattern.compile("\\[([0-9]+|\\*)\\]"); private static final JsonFactory JSON_FACTORY = new JsonFactory(); static { // Allows for unescaped ASCII control characters in JSON values JSON_FACTORY.enable(Feature.ALLOW_UNQUOTED_CONTROL_CHARS); JSON_FACTORY.enable(Feature.ALLOW_SINGLE_QUOTES); } private static final ObjectMapper MAPPER = new ObjectMapper(JSON_FACTORY); @SuppressWarnings("deprecation") private static final JavaType MAP_TYPE = TypeFactory.fromClass(Map.class); // An LRU cache using a linked hash map static class HashCache<K, V> extends LinkedHashMap<K, V> { private static final int CACHE_SIZE = 16; private static final int INIT_SIZE = 32; private static final float LOAD_FACTOR = 0.6f; HashCache() { super(INIT_SIZE, LOAD_FACTOR); } private static final long serialVersionUID = 1; @Override protected boolean removeEldestEntry(Map.Entry<K, V> eldest) { return size() > CACHE_SIZE; } } static Map<String, Object> extractObjectCache = new HashCache<String, Object>(); static Map<String, String[]> pathExprCache = new HashCache<String, String[]>(); static Map<String, ArrayList<String>> indexListCache = new HashCache<String, ArrayList<String>>(); static Map<String, String> mKeyGroup1Cache = new HashCache<String, String>(); static Map<String, Boolean> mKeyMatchesCache = new HashCache<String, Boolean>(); Text result = new Text(); public JsonUtil() {} @SuppressWarnings("rawtypes") public List<String> evaluateArray(String jsonString, String pathString) throws JsonParseException, JsonMappingException, IOException { List<String> list = new ArrayList<String>(); if (jsonString == null || jsonString == "" || pathString == null || pathString == "") { return null; } List result = MAPPER.readValue(jsonString, new TypeReference<List>() {}); String[] arr = pathString.split(",", -1); for (Object o : result) { if (o instanceof LinkedHashMap) { LinkedHashMap m = (LinkedHashMap) o; if (arr.length == 1) list.add(m.get(pathString).toString()); else if (arr.length > 1) { StringBuilder sb = new StringBuilder(); for (String path : arr) { sb.append(m.get(path).toString() + ","); } if (sb.length() > 0) sb.setLength(sb.length() - 1); list.add(sb.toString()); } } else if (o instanceof String) { String str = (String) o; str = str.replaceAll(Const.ROWKEY_DEFAULT_SEPARATOR, ","); list.add(str); } } return list; } @SuppressWarnings("rawtypes") public Set<String> evaluateDistinctArray(String jsonString, String pathString) throws JsonParseException, JsonMappingException, IOException { Set<String> set = new HashSet<String>(); if (jsonString == null || jsonString == "" || pathString == null || pathString == "") { return null; } List result = MAPPER.readValue(jsonString, new TypeReference<List>() {}); for (Object o : result) { if (o instanceof LinkedHashMap) { LinkedHashMap m = (LinkedHashMap) o; set.add(m.get(pathString).toString()); } else if (o instanceof String) { String str = (String) o; String[] arr = str.split(Const.ROWKEY_DEFAULT_SEPARATOR, -1); for (String s : arr) { set.add(s); } } } return set; } /** * Extract json object from a json string based on json path specified, and return json string of * the extracted json object. It will return null if the input json string is invalid. * * <p>A limited version of JSONPath supported: $ : Root object . : Child operator [] : Subscript * operator for array * : Wildcard for [] * * <p>Syntax not supported that's worth noticing: '' : Zero length string as key .. : Recursive * descent &#064; : Current object/element () : Script expression ?() : Filter (script) * expression. [,] : Union operator [start:end:step] : array slice operator * * @param jsonString the json string. * @param pathString the json path expression. * @return json string or null when an error happens. */ public Text evaluate(String jsonString, String pathString) { if (jsonString == null || jsonString == "" || pathString == null || pathString == "") { return null; } // Cache pathExpr String[] pathExpr = pathExprCache.get(pathString); if (pathExpr == null) { pathExpr = pathString.split("\\.", -1); pathExprCache.put(pathString, pathExpr); } if (!pathExpr[0].equalsIgnoreCase("$")) { return null; } // Cache extractObject Object extractObject = extractObjectCache.get(jsonString); if (extractObject == null) { try { extractObject = MAPPER.readValue(jsonString, MAP_TYPE); } catch (Exception e) { e.printStackTrace(); return null; } extractObjectCache.put(jsonString, extractObject); } for (int i = 1; i < pathExpr.length; i++) { if (extractObject == null) { return null; } extractObject = extract(extractObject, pathExpr[i]); } if (extractObject instanceof Map || extractObject instanceof List) { try { result.set(MAPPER.writeValueAsString(extractObject)); } catch (Exception e) { return null; } } else if (extractObject != null) { result.set(extractObject.toString()); } else { return null; } return result; } private Object extract(Object json, String path) { // Cache patternkey.matcher(path).matches() Matcher mKey = null; Boolean mKeyMatches = mKeyMatchesCache.get(path); if (mKeyMatches == null) { mKey = patternKey.matcher(path); mKeyMatches = mKey.matches() ? Boolean.TRUE : Boolean.FALSE; mKeyMatchesCache.put(path, mKeyMatches); } if (!mKeyMatches.booleanValue()) { return null; } // Cache mkey.group(1) String mKeyGroup1 = mKeyGroup1Cache.get(path); if (mKeyGroup1 == null) { if (mKey == null) { mKey = patternKey.matcher(path); } mKeyGroup1 = mKey.group(1); mKeyGroup1Cache.put(path, mKeyGroup1); } json = extract_json_withkey(json, mKeyGroup1); // Cache indexList ArrayList<String> indexList = indexListCache.get(path); if (indexList == null) { Matcher mIndex = patternIndex.matcher(path); indexList = new ArrayList<String>(); while (mIndex.find()) { indexList.add(mIndex.group(1)); } indexListCache.put(path, indexList); } if (indexList.size() > 0) { json = extract_json_withindex(json, indexList); } return json; } List<Object> jsonList = new ArrayList<Object>(); @SuppressWarnings("unchecked") private Object extract_json_withindex(Object json, ArrayList<String> indexList) { jsonList.clear(); jsonList.add(json); Iterator<String> itr = indexList.iterator(); while (itr.hasNext()) { String index = itr.next(); List<Object> tmp_jsonList = new ArrayList<Object>(); if (index.equalsIgnoreCase("*")) { for (int i = 0; i < jsonList.size(); i++) { Object array = jsonList.get(i); if (array instanceof List) { for (int j = 0; j < ((List<Object>) array).size(); j++) { tmp_jsonList.add(((List<Object>) array).get(j)); } } } jsonList = tmp_jsonList; } else { for (int i = 0; i < (jsonList).size(); i++) { Object array = jsonList.get(i); int indexValue = Integer.parseInt(index); if (!(array instanceof List)) { continue; } if (indexValue >= ((List<Object>) array).size()) { return null; } tmp_jsonList.add(((List<Object>) array).get(indexValue)); jsonList = tmp_jsonList; } } } if (jsonList.isEmpty()) { return null; } return (jsonList.size() > 1) ? new ArrayList<Object>(jsonList) : jsonList.get(0); } @SuppressWarnings("unchecked") private Object extract_json_withkey(Object json, String path) { if (json instanceof List) { List<Object> jsonArray = new ArrayList<Object>(); for (int i = 0; i < ((List<Object>) json).size(); i++) { Object json_elem = ((List<Object>) json).get(i); Object json_obj = null; if (json_elem instanceof Map) { json_obj = ((Map<String, Object>) json_elem).get(path); } else { continue; } if (json_obj instanceof List) { for (int j = 0; j < ((List<Object>) json_obj).size(); j++) { jsonArray.add(((List<Object>) json_obj).get(j)); } } else if (json_obj != null) { jsonArray.add(json_obj); } } return (jsonArray.size() == 0) ? null : jsonArray; } else if (json instanceof Map) { return ((Map<String, Object>) json).get(path); } else { return null; } } @SuppressWarnings("rawtypes") public static void main(String[] args) throws JsonParseException, IOException { String json = "{'channel':'14','videoid':'5815053'}"; json = "[{\"ID\":\"\",\"area\":\"欧美\",\"category\":\"剧情\",\"counter\":2,\"time\":2,\"type\":\"电影\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"欧美\",\"category\":\"动作\",\"counter\":36,\"time\":36,\"type\":\"电影\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"内地\",\"category\":\"剧情\",\"counter\":10,\"time\":10,\"type\":\"电视\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"港台\",\"category\":\"剧情\",\"counter\":22,\"time\":22,\"type\":\"电影\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"内地\",\"category\":\"战争\",\"counter\":8,\"time\":8,\"type\":\"电视\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"欧美\",\"category\":\"惊悚\",\"counter\":35,\"time\":35,\"type\":\"电影\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"内地\",\"category\":\"剧情\",\"counter\":5,\"time\":5,\"type\":\"电影\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"内地\",\"category\":\"爱情\",\"counter\":18,\"time\":18,\"type\":\"电视\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"港台\",\"category\":\"动作\",\"counter\":124,\"time\":124,\"type\":\"电影\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"港台\",\"category\":\"喜剧\",\"counter\":21,\"time\":21,\"type\":\"电影\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"欧美\",\"category\":\"科幻\",\"counter\":34,\"time\":34,\"type\":\"电影\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"欧美\",\"category\":\"喜剧\",\"counter\":1,\"time\":1,\"type\":\"电影\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"内地\",\"category\":\"古装\",\"counter\":7,\"time\":7,\"type\":\"电视\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"内地\",\"category\":\"都市\",\"counter\":47,\"time\":47,\"type\":\"电视\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"欧美\",\"category\":\"爱情\",\"counter\":3,\"time\":3,\"type\":\"电影\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"内地\",\"category\":\"爱情\",\"counter\":13,\"time\":13,\"type\":\"电影\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"内地\",\"category\":\"喜剧\",\"counter\":16,\"time\":16,\"type\":\"电影\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"港台\",\"category\":\"爱情\",\"counter\":23,\"time\":23,\"type\":\"电影\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"欧美\",\"category\":\"犯罪\",\"counter\":135,\"time\":135,\"type\":\"电影\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"内地\",\"category\":\"喜剧\",\"counter\":281,\"time\":281,\"type\":\"电视\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"韩国\",\"category\":\"剧情\",\"counter\":358,\"time\":358,\"type\":\"电影\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"内地\",\"category\":\"动作\",\"counter\":4,\"time\":4,\"type\":\"电影\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"港台\",\"category\":\"犯罪\",\"counter\":33,\"time\":33,\"type\":\"电影\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"日本\",\"category\":\"校园\",\"counter\":43,\"time\":43,\"type\":\"动漫\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"内地\",\"category\":\"警匪\",\"counter\":9,\"time\":9,\"type\":\"电视\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"日本\",\"category\":\"热血\",\"counter\":42,\"time\":42,\"type\":\"动漫\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"港台\",\"category\":\"悬疑\",\"counter\":55,\"time\":55,\"type\":\"电影\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"内地\",\"category\":\"家庭\",\"counter\":58,\"time\":58,\"type\":\"电视\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"港台\",\"category\":\"都市\",\"counter\":70,\"time\":70,\"type\":\"电视\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"欧美\",\"category\":\"战争\",\"counter\":119,\"time\":119,\"type\":\"电影\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"内地\",\"category\":\"娱乐\",\"counter\":284,\"time\":284,\"type\":\"综艺\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"港台\",\"category\":\"警匪\",\"counter\":363,\"time\":363,\"type\":\"电影\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"韩国\",\"category\":\"爱情\",\"counter\":449,\"time\":449,\"type\":\"电影\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"港台\",\"category\":\"惊悚\",\"counter\":32,\"time\":32,\"type\":\"电影\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"欧美\",\"category\":\"悬疑\",\"counter\":61,\"time\":61,\"type\":\"电影\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"内地\",\"category\":\"悬疑\",\"counter\":226,\"time\":226,\"type\":\"电影\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"内地\",\"category\":\"悬疑\",\"counter\":11,\"time\":11,\"type\":\"电视\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"欧美\",\"category\":\"伦理\",\"counter\":29,\"time\":29,\"type\":\"电影\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"日本\",\"category\":\"励志\",\"counter\":44,\"time\":44,\"type\":\"动漫\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"韩国\",\"category\":\"浪漫\",\"counter\":69,\"time\":69,\"type\":\"电视\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"欧美\",\"category\":\"校园\",\"counter\":71,\"time\":71,\"type\":\"动漫\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"日本\",\"category\":\"冒险\",\"counter\":77,\"time\":77,\"type\":\"动漫\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"内地\",\"category\":\"犯罪\",\"counter\":161,\"time\":161,\"type\":\"电影\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"内地\",\"category\":\"伦理\",\"counter\":162,\"time\":162,\"type\":\"电影\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"内地\",\"category\":\"魔幻\",\"counter\":245,\"time\":245,\"type\":\"电影\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"内地\",\"category\":\"武侠\",\"counter\":20,\"time\":20,\"type\":\"电视\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"日本\",\"category\":\"恶搞\",\"counter\":45,\"time\":45,\"type\":\"动漫\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"日本\",\"category\":\"魔幻\",\"counter\":46,\"time\":46,\"type\":\"动漫\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"内地\",\"category\":\"萌系\",\"counter\":92,\"time\":92,\"type\":\"动漫\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"欧美\",\"category\":\"警匪\",\"counter\":134,\"time\":134,\"type\":\"电影\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"内地\",\"category\":\"武侠\",\"counter\":6,\"time\":6,\"type\":\"电影\",\"uid\":\"\"},{\"ID\":\"\",\"area\":\"欧美\",\"category\":\"推理\",\"counter\":51,\"time\":51,\"type\":\"动漫\",\"uid\":\"\"}]"; // JsonFactory f = new JsonFactory(); // JsonParser jp = f.createJsonParser(json); // BufferedReader br = new BufferedReader(new InputStreamReader( // new FileInputStream("/root/test.txt"))); // String line = null; // while (null != (line = br.readLine())) { // json = line; // } System.out.println(json); List result = MAPPER.readValue(json, new TypeReference<List>() {}); System.out.println(result); for (Object o : result) { LinkedHashMap m = (LinkedHashMap) o; System.out.println((String) m.get("area") + "\t" + m.get("category") + "\t" + m.get("type")); } JsonUtil u = new JsonUtil(); List<String> list = u.evaluateArray(json, "area,category,type"); for (String s : list) { System.out.println(s); } } }
/** UDFJson. */ @Description( name = "get_json_object", value = "_FUNC_(json_txt, path) - Extract a json object from path ", extended = "Extract json object from a json string based on json path " + "specified, and return json string of the extracted json object. It " + "will return null if the input json string is invalid.\n" + "A limited version of JSONPath supported:\n" + " $ : Root object\n" + " . : Child operator\n" + " [] : Subscript operator for array\n" + " * : Wildcard for []\n" + "Syntax not supported that's worth noticing:\n" + " '' : Zero length string as key\n" + " .. : Recursive descent\n" + " &#064; : Current object/element\n" + " () : Script expression\n" + " ?() : Filter (script) expression.\n" + " [,] : Union operator\n" + " [start:end:step] : array slice operator\n") public class UDFJson extends UDF { private final Pattern patternKey = Pattern.compile("^([a-zA-Z0-9_\\-\\:\\s]+).*"); private final Pattern patternIndex = Pattern.compile("\\[([0-9]+|\\*)\\]"); private static final JsonFactory JSON_FACTORY = new JsonFactory(); static { // Allows for unescaped ASCII control characters in JSON values JSON_FACTORY.enable(Feature.ALLOW_UNQUOTED_CONTROL_CHARS); } private static final ObjectMapper MAPPER = new ObjectMapper(JSON_FACTORY); private static final JavaType MAP_TYPE = TypeFactory.fromClass(Map.class); // An LRU cache using a linked hash map static class HashCache<K, V> extends LinkedHashMap<K, V> { private static final int CACHE_SIZE = 16; private static final int INIT_SIZE = 32; private static final float LOAD_FACTOR = 0.6f; HashCache() { super(INIT_SIZE, LOAD_FACTOR); } private static final long serialVersionUID = 1; @Override protected boolean removeEldestEntry(Map.Entry<K, V> eldest) { return size() > CACHE_SIZE; } } static Map<String, Object> extractObjectCache = new HashCache<String, Object>(); static Map<String, String[]> pathExprCache = new HashCache<String, String[]>(); static Map<String, ArrayList<String>> indexListCache = new HashCache<String, ArrayList<String>>(); static Map<String, String> mKeyGroup1Cache = new HashCache<String, String>(); static Map<String, Boolean> mKeyMatchesCache = new HashCache<String, Boolean>(); Text result = new Text(); public UDFJson() {} /** * Extract json object from a json string based on json path specified, and return json string of * the extracted json object. It will return null if the input json string is invalid. * * <p>A limited version of JSONPath supported: $ : Root object . : Child operator [] : Subscript * operator for array * : Wildcard for [] * * <p>Syntax not supported that's worth noticing: '' : Zero length string as key .. : Recursive * descent &#064; : Current object/element () : Script expression ?() : Filter (script) * expression. [,] : Union operator [start:end:step] : array slice operator * * @param jsonString the json string. * @param pathString the json path expression. * @return json string or null when an error happens. */ public Text evaluate(String jsonString, String pathString) { if (jsonString == null || jsonString == "" || pathString == null || pathString == "") { return null; } // Cache pathExpr String[] pathExpr = pathExprCache.get(pathString); if (pathExpr == null) { pathExpr = pathString.split("\\.", -1); pathExprCache.put(pathString, pathExpr); } if (!pathExpr[0].equalsIgnoreCase("$")) { return null; } // Cache extractObject Object extractObject = extractObjectCache.get(jsonString); if (extractObject == null) { try { extractObject = MAPPER.readValue(jsonString, MAP_TYPE); } catch (Exception e) { return null; } extractObjectCache.put(jsonString, extractObject); } for (int i = 1; i < pathExpr.length; i++) { if (extractObject == null) { return null; } extractObject = extract(extractObject, pathExpr[i]); } if (extractObject instanceof Map || extractObject instanceof List) { try { result.set(MAPPER.writeValueAsString(extractObject)); } catch (Exception e) { return null; } } else if (extractObject != null) { result.set(extractObject.toString()); } else { return null; } return result; } private Object extract(Object json, String path) { // Cache patternkey.matcher(path).matches() Matcher mKey = null; Boolean mKeyMatches = mKeyMatchesCache.get(path); if (mKeyMatches == null) { mKey = patternKey.matcher(path); mKeyMatches = mKey.matches() ? Boolean.TRUE : Boolean.FALSE; mKeyMatchesCache.put(path, mKeyMatches); } if (!mKeyMatches.booleanValue()) { return null; } // Cache mkey.group(1) String mKeyGroup1 = mKeyGroup1Cache.get(path); if (mKeyGroup1 == null) { if (mKey == null) { mKey = patternKey.matcher(path); } mKeyGroup1 = mKey.group(1); mKeyGroup1Cache.put(path, mKeyGroup1); } json = extract_json_withkey(json, mKeyGroup1); // Cache indexList ArrayList<String> indexList = indexListCache.get(path); if (indexList == null) { Matcher mIndex = patternIndex.matcher(path); indexList = new ArrayList<String>(); while (mIndex.find()) { indexList.add(mIndex.group(1)); } indexListCache.put(path, indexList); } if (indexList.size() > 0) { json = extract_json_withindex(json, indexList); } return json; } List<Object> jsonList = new ArrayList<Object>(); @SuppressWarnings("unchecked") private Object extract_json_withindex(Object json, ArrayList<String> indexList) { jsonList.clear(); jsonList.add(json); Iterator<String> itr = indexList.iterator(); while (itr.hasNext()) { String index = itr.next(); List<Object> tmp_jsonList = new ArrayList<Object>(); if (index.equalsIgnoreCase("*")) { for (int i = 0; i < jsonList.size(); i++) { Object array = jsonList.get(i); if (array instanceof List) { for (int j = 0; j < ((List<Object>) array).size(); j++) { tmp_jsonList.add(((List<Object>) array).get(j)); } } } jsonList = tmp_jsonList; } else { for (int i = 0; i < (jsonList).size(); i++) { Object array = jsonList.get(i); int indexValue = Integer.parseInt(index); if (!(array instanceof List)) { continue; } if (indexValue >= ((List<Object>) array).size()) { return null; } tmp_jsonList.add(((List<Object>) array).get(indexValue)); jsonList = tmp_jsonList; } } } if (jsonList.isEmpty()) { return null; } return (jsonList.size() > 1) ? new ArrayList<Object>(jsonList) : jsonList.get(0); } @SuppressWarnings("unchecked") private Object extract_json_withkey(Object json, String path) { if (json instanceof List) { List<Object> jsonArray = new ArrayList<Object>(); for (int i = 0; i < ((List<Object>) json).size(); i++) { Object json_elem = ((List<Object>) json).get(i); Object json_obj = null; if (json_elem instanceof Map) { json_obj = ((Map<String, Object>) json_elem).get(path); } else { continue; } if (json_obj instanceof List) { for (int j = 0; j < ((List<Object>) json_obj).size(); j++) { jsonArray.add(((List<Object>) json_obj).get(j)); } } else if (json_obj != null) { jsonArray.add(json_obj); } } return (jsonArray.size() == 0) ? null : jsonArray; } else if (json instanceof Map) { return ((Map<String, Object>) json).get(path); } else { return null; } } }