diff options
Diffstat (limited to 'libs/utils/WordPressUtils/src/main/java/org/wordpress/android/util/JSONUtil.java')
| -rw-r--r-- | libs/utils/WordPressUtils/src/main/java/org/wordpress/android/util/JSONUtil.java | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/libs/utils/WordPressUtils/src/main/java/org/wordpress/android/util/JSONUtil.java b/libs/utils/WordPressUtils/src/main/java/org/wordpress/android/util/JSONUtil.java new file mode 100644 index 000000000..199fba703 --- /dev/null +++ b/libs/utils/WordPressUtils/src/main/java/org/wordpress/android/util/JSONUtil.java @@ -0,0 +1,236 @@ +package org.wordpress.android.util; + +import android.text.TextUtils; + +import org.json.JSONArray; +import org.json.JSONException; +import org.json.JSONObject; +import org.wordpress.android.util.AppLog.T; + +import java.util.ArrayList; + +public class JSONUtil { + private static String QUERY_SEPERATOR="."; + private static String QUERY_ARRAY_INDEX_START="["; + private static String QUERY_ARRAY_INDEX_END="]"; + private static String QUERY_ARRAY_FIRST="first"; + private static String QUERY_ARRAY_LAST="last"; + + private static final String JSON_NULL_STR = "null"; + + private static final String TAG="JSONUtil"; + /** + * Given a JSONObject and a key path (e.g property.child) and a default it will + * traverse the object graph and pull out the desired property + */ + public static <U> U queryJSON(JSONObject source, String query, U defaultObject) { + int nextSeperator = query.indexOf(QUERY_SEPERATOR); + int nextIndexStart = query.indexOf(QUERY_ARRAY_INDEX_START); + if (nextSeperator == -1 && nextIndexStart == -1) { + // last item let's get it + try { + if (!source.has(query)) { + return defaultObject; + } + Object result = source.get(query); + if (result.getClass().isAssignableFrom(defaultObject.getClass())) { + return (U) result; + } else { + return defaultObject; + } + } catch (java.lang.ClassCastException e) { + AppLog.e(T.UTILS, "Unable to cast the object to " + defaultObject.getClass().getName(), e); + return defaultObject; + } catch (JSONException e) { + AppLog.e(T.UTILS, "Unable to get the Key from the input object. Key:" + query, e); + return defaultObject; + } + } + int endQuery; + if (nextSeperator == -1 || nextIndexStart == -1) { + endQuery = Math.max(nextSeperator, nextIndexStart); + } else { + endQuery = Math.min(nextSeperator, nextIndexStart); + } + String nextQuery = query.substring(endQuery); + String key = query.substring(0, endQuery); + try { + if (source == null) { + return defaultObject; + } + if (nextQuery.indexOf(QUERY_SEPERATOR) == 0) { + return queryJSON(source.getJSONObject(key), nextQuery.substring(1), defaultObject); + } else if (nextQuery.indexOf(QUERY_ARRAY_INDEX_START) == 0) { + return queryJSON(source.getJSONArray(key), nextQuery, defaultObject); + } else if (!nextQuery.equals("")) { + return defaultObject; + } + Object result = source.get(key); + if (result.getClass().isAssignableFrom(defaultObject.getClass())) { + return (U) result; + } else { + AppLog.w(T.UTILS, String.format("The returned object type %s is not assignable to the type %s. Using default!", + result.getClass(),defaultObject.getClass())); + return defaultObject; + } + } catch (java.lang.ClassCastException e) { + AppLog.e(T.UTILS, "Unable to cast the object to " + defaultObject.getClass().getName(), e); + return defaultObject; + } catch (JSONException e) { + AppLog.e(T.UTILS, "Unable to get the Key from the input object. Key:" + query, e); + return defaultObject; + } + } + + /** + * Given a JSONArray and a query (e.g. [0].property) it will traverse the array and + * pull out the requested property. + * + * Acceptable indexes include negative numbers to reference items from the end of + * the list as well as "last" and "first" as more explicit references to "0" and "-1" + */ + public static <U> U queryJSON(JSONArray source, String query, U defaultObject){ + // query must start with [ have an index and then have ] + int indexStart = query.indexOf(QUERY_ARRAY_INDEX_START); + int indexEnd = query.indexOf(QUERY_ARRAY_INDEX_END); + if (indexStart == -1 || indexEnd == -1 || indexStart > indexEnd) { + return defaultObject; + } + // get "index" from "[index]" + String indexStr = query.substring(indexStart + 1, indexEnd); + int index; + if (indexStr.equals(QUERY_ARRAY_FIRST)) { + index = 0; + } else if (indexStr.equals(QUERY_ARRAY_LAST)) { + index = -1; + } else { + index = Integer.parseInt(indexStr); + } + if (index < 0) { + index = source.length() + index; + } + // copy remaining query + String remainingQuery = query.substring(indexEnd + 1); + try { + if (remainingQuery.indexOf(QUERY_ARRAY_INDEX_START) == 0) { + return queryJSON(source.getJSONArray(index), remainingQuery, defaultObject); + } else if (remainingQuery.indexOf(QUERY_SEPERATOR) == 0) { + return queryJSON(source.getJSONObject(index), remainingQuery.substring(1), defaultObject); + } else if (!remainingQuery.equals("")) { + // TODO throw an exception since the query isn't valid? + AppLog.w(T.UTILS, String.format("Incorrect query for next object %s", remainingQuery)); + return defaultObject; + } + Object result = source.get(index); + if (result.getClass().isAssignableFrom(defaultObject.getClass())) { + return (U) result; + } else { + AppLog.w(T.UTILS, String.format("The returned object type %s is not assignable to the type %s. Using default!", + result.getClass(),defaultObject.getClass())); + return defaultObject; + } + } catch (java.lang.ClassCastException e) { + AppLog.e(T.UTILS, "Unable to cast the object to "+defaultObject.getClass().getName(), e); + return defaultObject; + } catch (JSONException e) { + AppLog.e(T.UTILS, "Unable to get the Key from the input object. Key:" + query, e); + return defaultObject; + } + } + + /** + * Convert a JSONArray (expected to contain strings) in a string list + */ + public static ArrayList<String> fromJSONArrayToStringList(JSONArray jsonArray) { + ArrayList<String> stringList = new ArrayList<String>(); + for (int i = 0; i < jsonArray.length(); i++) { + try { + stringList.add(jsonArray.getString(i)); + } catch (JSONException e) { + AppLog.e(T.UTILS, e); + } + } + return stringList; + } + + /** + * Convert a string list in a JSONArray + */ + public static JSONArray fromStringListToJSONArray(ArrayList<String> stringList) { + JSONArray jsonArray = new JSONArray(); + if (stringList != null) { + for (int i = 0; i < stringList.size(); i++) { + jsonArray.put(stringList.get(i)); + } + } + return jsonArray; + } + + /* + * wrapper for JSONObject.optString() which handles "null" values + */ + public static String getString(JSONObject json, String name) { + String value = json.optString(name); + // return empty string for "null" + if (JSON_NULL_STR.equals(value)) + return ""; + return value; + } + + /* + * use with strings that contain HTML entities + */ + public static String getStringDecoded(JSONObject json, String name) { + String value = getString(json, name); + return HtmlUtils.fastUnescapeHtml(value); + } + + /* + * replacement for JSONObject.optBoolean() - optBoolean() only checks for "true" and "false", + * but our API sometimes uses "0" to denote false + */ + public static boolean getBool(JSONObject json, String name) { + String value = getString(json, name); + if (TextUtils.isEmpty(value)) + return false; + if (value.equals("0")) + return false; + if (value.equalsIgnoreCase("false")) + return false; + return true; + } + + /* + * returns the JSONObject child of the passed parent that matches the passed query + * this is basically an "optJSONObject" that supports nested queries, for example: + * + * getJSONChild("meta/data/site") + * + * would find this: + * + * "meta": { + * "data": { + * "site": { + * "ID": 3584907, + * "name": "WordPress.com News", + * } + * } + * } + */ + public static JSONObject getJSONChild(final JSONObject jsonParent, final String query) { + if (jsonParent == null || TextUtils.isEmpty(query)) + return null; + String[] names = query.split("/"); + JSONObject jsonChild = null; + for (int i = 0; i < names.length; i++) { + if (jsonChild == null) { + jsonChild = jsonParent.optJSONObject(names[i]); + } else { + jsonChild = jsonChild.optJSONObject(names[i]); + } + if (jsonChild == null) + return null; + } + return jsonChild; + } +}
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