Java tutorial
/* * Copyright (C) 2010 Google Inc. * * Licensed 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 com.google.i18n.addressinput.common; import org.json.JSONArray; import org.json.JSONException; import org.json.JSONObject; import org.json.JSONTokener; import java.util.ArrayList; import java.util.Iterator; /** * Compatibility methods on top of the JSON data. */ public final class JsoMap extends JSONObject { /** * Construct a JsoMap object given some json text. This method directly evaluates the String * that you pass in; no error or safety checking is performed, so be very careful about the * source of your data. * * @param json JSON text describing an address format * @return a JsoMap object made from the supplied JSON. */ public static JsoMap buildJsoMap(String json) throws JSONException { return new JsoMap(new JSONTokener(json)); } /** * Construct an empty JsoMap. * * @return the empty object. */ static JsoMap createEmptyJsoMap() { return new JsoMap(); } /** * constructor. */ protected JsoMap() { } private JsoMap(JSONTokener readFrom) throws JSONException { super(readFrom); } private JsoMap(JSONObject copyFrom, String[] names) throws JSONException { super(copyFrom, names); } /** * Remove the specified key. * * @param key key name. */ void delKey(String key) { super.remove(key); } /** * Retrieve the string value for specified key. * * @param key key name. * @return string value. * @throws ClassCastException, IllegalArgumentException. */ @Override public String get(String key) { try { Object o = super.get(key); if (o instanceof String) { return (String) o; } else if (o instanceof Integer) { throw new IllegalArgumentException(); } else { throw new ClassCastException(); } } catch (JSONException e) { return null; } } /** * Access JSONObject.get(String) which is shadowed by JsoMap.get(String). * * @param name A key string. * @return The object associated with the key. * @throws JSONException if the key is not found. */ private Object getObject(String name) throws JSONException { return super.get(name); } /** * Retrieves the integer value for specified key. * * @return integer value or -1 if value is undefined. */ @Override public int getInt(String key) { try { Object o = super.get(key); if (o instanceof Integer) { return ((Integer) o).intValue(); } else { throw new RuntimeException("Something other than an int was returned"); } } catch (JSONException e) { return -1; } } /** * Collect all the keys and return as a JSONArray. * * @return A JSONArray that contains all the keys. */ JSONArray getKeys() { // names() returns null if the array was empty! JSONArray names = super.names(); return names != null ? names : new JSONArray(); } /** * Retrieve the JsoMap object for specified key. * * @param key key name. * @return JsoMap object. * @throws ClassCastException, IllegalArgumentException. */ @SuppressWarnings("unchecked") // JSONObject.keys() has no type information. JsoMap getObj(String key) throws ClassCastException, IllegalArgumentException { try { Object o = super.get(key); if (o instanceof JSONObject) { JSONObject value = (JSONObject) o; ArrayList<String> keys = new ArrayList<String>(value.length()); for (Iterator<String> it = value.keys(); it.hasNext();) { keys.add(it.next()); } String[] names = new String[keys.size()]; return new JsoMap(value, keys.toArray(names)); } else if (o instanceof Integer) { throw new IllegalArgumentException(); } else { throw new ClassCastException(); } } catch (JSONException e) { return null; } } /** * Check if the object has specified key. * * @param key The key name to be checked. * @return true if key can be found. */ boolean containsKey(String key) { return super.has(key); } /** * Merge those keys not found in this object from specified object. * * @param obj The other object to be merged. */ void mergeData(JsoMap obj) { if (obj == null) { return; } JSONArray names = obj.names(); if (names == null) { return; } for (int i = 0; i < names.length(); i++) { try { String name = names.getString(i); try { if (!super.has(name)) { super.put(name, obj.getObject(name)); } } catch (JSONException e) { throw new RuntimeException(e); } } catch (JSONException e) { // Ignored. } } } /** * Save a string to string mapping into this map. * * @param key the string key. * @param value the String value. */ void put(String key, String value) { try { super.put(key, value); } catch (JSONException e) { throw new RuntimeException(e); } } /** * Save a string to integer mapping into this map. * * @param key the string key. * @param value the integer value. */ void putInt(String key, int value) { try { super.put(key, value); } catch (JSONException e) { throw new RuntimeException(e); } } /** * Save a string to JSONObject mapping into this map. * * @param key the string key. * @param value a JSONObject as value. */ void putObj(String key, JSONObject value) { try { super.put(key, value); } catch (JSONException e) { throw new RuntimeException(e); } } String string() throws ClassCastException, IllegalArgumentException { StringBuilder sb = new StringBuilder("JsoMap[\n"); JSONArray keys = getKeys(); for (int i = 0; i < keys.length(); i++) { String key; try { key = keys.getString(i); } catch (JSONException e) { throw new RuntimeException(e); } sb.append('(').append(key).append(':').append(get(key)).append(")\n"); } sb.append(']'); return sb.toString(); } String map() throws ClassCastException, IllegalArgumentException { StringBuilder sb = new StringBuilder("JsoMap[\n"); JSONArray keys = getKeys(); for (int i = 0; i < keys.length(); i++) { String key; try { key = keys.getString(i); } catch (JSONException e) { throw new RuntimeException(e); } sb.append('(').append(key).append(':').append(getObj(key).string()).append(")\n"); } sb.append(']'); return sb.toString(); } }