122 lines
4.6 KiB
Java
122 lines
4.6 KiB
Java
/*
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* Copyright (C) 2014 Tim Bray <tbray@textuality.com>
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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package org.sufficientlysecure.keychain.util;
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import org.json.JSONArray;
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import org.json.JSONException;
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import org.json.JSONObject;
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/**
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* Minimal hierarchy selector
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*
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* This is for picking out an item in a large multilevel JSON object, for example look at
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* the Keybase.io User object, documentation at https://keybase.io/__/api-docs/1.0#user-objects
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* an example available via
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* curl https://keybase.io/_/api/1.0/user/lookup.json?username=timbray
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*
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* If you want to retrieve the ascii-armored key, you'd say
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* String key = JWalk.getString(match,"them", "public_keys", "primary", "bundle");
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*/
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public class JWalk {
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/**
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* Returns an int member value from the JSON sub-object addressed by the path
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*
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* @param json The object
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* @param path list of string object member selectors
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* @return the int addressed by the path, assuming such a thing exists
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* @throws JSONException if any step in the path doesn’t work
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*/
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public static int getInt(JSONObject json, String... path) throws JSONException {
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json = walk(json, path);
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return json.getInt(path[path.length - 1]);
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}
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/**
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* Returns a long member value from the JSON sub-object addressed by the path
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*
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* @param json The object
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* @param path list of string object member selectors
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* @return the int addressed by the path, assuming such a thing exists
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* @throws JSONException if any step in the path doesn’t work
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*/
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public static long getLong(JSONObject json, String... path) throws JSONException {
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json = walk(json, path);
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return json.getLong(path[path.length - 1]);
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}
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/**
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* Returns a String member value from the JSON sub-object addressed by the path
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*
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* @param json The object
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* @param path list of string object member selectors
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* @return the int addressed by the path, assuming such a thing exists
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* @throws JSONException if any step in the path doesn’t work
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*/
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public static String getString(JSONObject json, String... path) throws JSONException {
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json = walk(json, path);
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return json.getString(path[path.length - 1]);
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}
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/**
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* Returns a JSONArray member value from the JSON sub-object addressed by the path
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*
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* @param json The object
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* @param path list of string object member selectors
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* @return the int addressed by the path, assuming such a thing exists
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* @throws JSONException if any step in the path doesn’t work
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*/
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public static JSONArray getArray(JSONObject json, String... path) throws JSONException {
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json = walk(json, path);
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return json.getJSONArray(path[path.length - 1]);
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}
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/**
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* Returns a JSONObject member value from the JSON sub-object addressed by the path, or null
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*
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* @param json The object
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* @param path list of string object member selectors
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* @return the int addressed by the path, assuming such a thing exists
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* @throws JSONException if any step in the path, except for the last, doesn’t work
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*/
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public static JSONObject optObject(JSONObject json, String... path) throws JSONException {
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json = walk(json, path);
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return json.optJSONObject(path[path.length - 1]);
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}
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private static JSONObject walk(JSONObject json, String... path) throws JSONException {
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int len = path.length - 1;
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int pathIndex = 0;
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try {
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while (pathIndex < len) {
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json = json.getJSONObject(path[pathIndex]);
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pathIndex++;
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}
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} catch (JSONException e) {
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// try to give ’em a nice-looking error
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StringBuilder sb = new StringBuilder();
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for (int i = 0; i < len; i++) {
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sb.append(path[i]).append('.');
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}
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sb.append(path[len]);
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throw new JSONException("JWalk error at step " + pathIndex + " of " + sb);
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}
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return json;
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}
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}
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