Parsing JSON documents with JSONObject on Android

/* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, * software distributed under the License is distributed on an * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * KIND, either express or implied. See the License for the * specific language governing permissions and limitations under the License. */ package org.apache.shindig.common.util; import com.google.common.collect.ImmutableSet; import com.google.common.collect.Maps; import org.json.JSONArray; import org.json.JSONException; import org.json.JSONObject; import java.util.Iterator; import java.util.Map; import java.util.Set; import java.util.regex.Matcher; import java.util.regex.Pattern; import javax.servlet.http.HttpServletRequest; /** * Utilities for converting a JSON object to and from a URL encoding */ public class JsonConversionUtil { private static final Pattern ARRAY_MATCH = Pattern.compile("(\\w+)\\((\\d+)\\)"); private static final Set<String> RESERVED_PARAMS = ImmutableSet.of("method", "id", "st"); public static JSONObject fromRequest(HttpServletRequest request) throws JSONException { //String methodName = request.getPathInfo().replaceAll("/", ""); JSONObject root = new JSONObject(); Map<String, String[]> params = (Map<String, String[]>) request.getParameterMap(); root.put("method", params.get("method")[0]); if (params.containsKey("id")) { root.put("id", params.get("id")[0]); } JSONObject paramsRoot = new JSONObject(); for (Map.Entry<String, String[]> entry : params.entrySet()) { if (!RESERVED_PARAMS.contains(entry.getKey().toLowerCase())) { String[] path = entry.getKey().split("\\."); JSONObject holder = buildHolder(paramsRoot, path, 0); holder.put(path[path.length - 1], convertToJsonValue(entry.getValue()[0])); } } if (paramsRoot.length() > 0) { root.put("params", paramsRoot); } return root; } public static Map<String, String> fromJson(JSONObject obj) throws JSONException { Map<String, String> result = Maps.newHashMap(); collect(obj, "", result); return result; } private static void collect(Object current, String prefix, Map<String, String> result) throws JSONException { if (current == null) { result.put(prefix, "null"); return; } if (current instanceof JSONObject) { JSONObject json = (JSONObject) current; Iterator keys = json.keys(); while (keys.hasNext()) { String key = (String) keys.next(); if (json.isNull(key)) { result.put(prefix + "." + key, "null"); } else { collect(json.get(key), prefix + "." + key, result); } } } else if (current instanceof JSONArray) { JSONArray jsonArr = (JSONArray) current; if (isAllLiterals(jsonArr)) { // The array is all simple value types String jsonArrayString = jsonArr.toString(); //Strip [ & ] jsonArrayString = jsonArrayString.substring(1, jsonArrayString.length() - 1); if (jsonArr.length() == 1) { jsonArrayString = "(" + jsonArrayString + ")"; } result.put(prefix, jsonArrayString); } else { for (int i = 0; i < jsonArr.length(); i++) { if (jsonArr.isNull(i)) { result.put(prefix + "(" + i + ")", "null"); } else { collect(jsonArr.get(i), prefix + "(" + i + ")", result); } } } } else { result.put(prefix, current.toString()); } } public static boolean isAllLiterals(JSONArray jsonArr) throws JSONException { for (int i = 0; i < jsonArr.length(); i++) { if (!jsonArr.isNull(i) && (jsonArr.get(i) instanceof JSONObject || jsonArr.get(i) instanceof JSONArray)) { return false; } } return true; } static JSONObject parametersToJsonObject(Map<String, String> params) throws JSONException { JSONObject root = new JSONObject(); for (Map.Entry<String, String> entry : params.entrySet()) { String[] path = entry.getKey().split("\\."); JSONObject holder = buildHolder(root, path, 0); if (path.length > 1) { holder.put(path[path.length - 1], convertToJsonValue(entry.getValue())); } else { holder.put(path[0], convertToJsonValue(entry.getValue())); } } return root; } /** * Parse the steps in the path into JSON Objects. */ static JSONObject buildHolder(JSONObject root, String[] steps, int currentStep) throws JSONException { if (currentStep > steps.length - 2) { return root; } else { Matcher matcher = ARRAY_MATCH.matcher(steps[currentStep]); if (matcher.matches()) { // Handle as array String fieldName = matcher.group(1); int index = Integer.parseInt(matcher.group(2)); JSONArray newArrayStep; if (root.has(fieldName)) { newArrayStep = root.getJSONArray(fieldName); } else { newArrayStep = new JSONArray(); root.put(fieldName, newArrayStep); } JSONObject newStep = new JSONObject(); newArrayStep.put(index, newStep); return buildHolder(newStep, steps, ++currentStep); } else { JSONObject newStep; if (root.has(steps[currentStep])) { newStep = root.getJSONObject(steps[currentStep]); } else { newStep = new JSONObject(); root.put(steps[currentStep], newStep); } return buildHolder(newStep, steps, ++currentStep); } } } static Object convertToJsonValue(String value) throws JSONException { if (value == null) { return null; } else if (value.startsWith("(") && value.endsWith(")")) { // explicit form of literal array return new JSONArray("[" + value.substring(1, value.length() - 1) + "]"); } else { try { // inferred parsing of literal array // Attempt to parse as an array of literals JSONArray parsedArray = new JSONArray("[" + value + "]"); if (parsedArray.length() == 1) { // Not an array return parsedArray.get(0); } return parsedArray; } catch (JSONException je) { return value; } } } }