Java tutorial
/** * Copyright 2015 Zhenguo Jin * * 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.lemon.util; import com.google.gson.Gson; import org.json.JSONArray; import org.json.JSONException; import org.json.JSONObject; import java.util.ArrayList; import java.util.HashMap; import java.util.Iterator; import java.util.List; import java.util.Map; /** * Json? ??GoogleGSON * * Created by zhenguo on 4/17/15. */ public final class JSONUtils { public static boolean isPrintException = true; private JSONUtils() { throw new Error("Do not need instantiate!"); } /** * get Long from jsonObject * * @param jsonObject * @param key * @param defaultValue * @return <ul> * <li>if jsonObject is null, return defaultValue</li> * <li>if key is null or empty, return defaultValue</li> * <li>if {@link JSONObject#getLong(String)} exception, return defaultValue</li> * <li>return {@link JSONObject#getLong(String)}</li> * </ul> */ public static Long getLong(JSONObject jsonObject, String key, Long defaultValue) { if (jsonObject == null || StringUtils.isEmpty(key)) { return defaultValue; } try { return jsonObject.getLong(key); } catch (JSONException e) { if (isPrintException) { e.printStackTrace(); } return defaultValue; } } /** * get Long from jsonData * * @param jsonData * @param key * @param defaultValue * @return <ul> * <li>if jsonObject is null, return defaultValue</li> * <li>if jsonData {@link JSONObject#JSONObject(String)} exception, return defaultValue</li> * <li>return {@link JSONUtils#getLong(JSONObject, String, Long)}</li> * </ul> */ public static Long getLong(String jsonData, String key, Long defaultValue) { if (StringUtils.isEmpty(jsonData)) { return defaultValue; } try { JSONObject jsonObject = new JSONObject(jsonData); return getLong(jsonObject, key, defaultValue); } catch (JSONException e) { if (isPrintException) { e.printStackTrace(); } return defaultValue; } } /** * @param jsonObject * @param key * @param defaultValue * @return * @see JSONUtils#getLong(JSONObject, String, Long) */ public static long getLong(JSONObject jsonObject, String key, long defaultValue) { return getLong(jsonObject, key, (Long) defaultValue); } /** * @param jsonData * @param key * @param defaultValue * @return * @see JSONUtils#getLong(String, String, Long) */ public static long getLong(String jsonData, String key, long defaultValue) { return getLong(jsonData, key, (Long) defaultValue); } /** * get Int from jsonObject * * @param jsonObject * @param key * @param defaultValue * @return <ul> * <li>if jsonObject is null, return defaultValue</li> * <li>if key is null or empty, return defaultValue</li> * <li>if {@link JSONObject#getInt(String)} exception, return defaultValue</li> * <li>return {@link JSONObject#getInt(String)}</li> * </ul> */ public static Integer getInt(JSONObject jsonObject, String key, Integer defaultValue) { if (jsonObject == null || StringUtils.isEmpty(key)) { return defaultValue; } try { return jsonObject.getInt(key); } catch (JSONException e) { if (isPrintException) { e.printStackTrace(); } return defaultValue; } } /** * get Int from jsonData * * @param jsonData * @param key * @param defaultValue * @return <ul> * <li>if jsonObject is null, return defaultValue</li> * <li>if jsonData {@link JSONObject#JSONObject(String)} exception, return defaultValue</li> * <li>return {@link JSONUtils#getInt(JSONObject, String, Integer)}</li> * </ul> */ public static Integer getInt(String jsonData, String key, Integer defaultValue) { if (StringUtils.isEmpty(jsonData)) { return defaultValue; } try { JSONObject jsonObject = new JSONObject(jsonData); return getInt(jsonObject, key, defaultValue); } catch (JSONException e) { if (isPrintException) { e.printStackTrace(); } return defaultValue; } } /** * @param jsonObject * @param key * @param defaultValue * @return * @see JSONUtils#getInt(JSONObject, String, Integer) */ public static int getInt(JSONObject jsonObject, String key, int defaultValue) { return getInt(jsonObject, key, (Integer) defaultValue); } /** * @param jsonData * @param key * @param defaultValue * @return * @see JSONUtils#getInt(String, String, Integer) */ public static int getInt(String jsonData, String key, int defaultValue) { return getInt(jsonData, key, (Integer) defaultValue); } /** * get Double from jsonObject * * @param jsonObject * @param key * @param defaultValue * @return <ul> * <li>if jsonObject is null, return defaultValue</li> * <li>if key is null or empty, return defaultValue</li> * <li>if {@link JSONObject#getDouble(String)} exception, return defaultValue</li> * <li>return {@link JSONObject#getDouble(String)}</li> * </ul> */ public static Double getDouble(JSONObject jsonObject, String key, Double defaultValue) { if (jsonObject == null || StringUtils.isEmpty(key)) { return defaultValue; } try { return jsonObject.getDouble(key); } catch (JSONException e) { if (isPrintException) { e.printStackTrace(); } return defaultValue; } } /** * get Double from jsonData * * @param jsonData * @param key * @param defaultValue * @return <ul> * <li>if jsonObject is null, return defaultValue</li> * <li>if jsonData {@link JSONObject#JSONObject(String)} exception, return defaultValue</li> * <li>return {@link JSONUtils#getDouble(JSONObject, String, Double)}</li> * </ul> */ public static Double getDouble(String jsonData, String key, Double defaultValue) { if (StringUtils.isEmpty(jsonData)) { return defaultValue; } try { JSONObject jsonObject = new JSONObject(jsonData); return getDouble(jsonObject, key, defaultValue); } catch (JSONException e) { if (isPrintException) { e.printStackTrace(); } return defaultValue; } } /** * @param jsonObject * @param key * @param defaultValue * @return * @see JSONUtils#getDouble(JSONObject, String, Double) */ public static double getDouble(JSONObject jsonObject, String key, double defaultValue) { return getDouble(jsonObject, key, (Double) defaultValue); } /** * @param jsonData * @param key * @param defaultValue * @return * @see JSONUtils#getDouble(String, String, Double) */ public static double getDouble(String jsonData, String key, double defaultValue) { return getDouble(jsonData, key, (Double) defaultValue); } /** * get String from jsonObject * * @param jsonObject * @param key * @param defaultValue * @return <ul> * <li>if jsonObject is null, return defaultValue</li> * <li>if key is null or empty, return defaultValue</li> * <li>if {@link JSONObject#getString(String)} exception, return defaultValue</li> * <li>return {@link JSONObject#getString(String)}</li> * </ul> */ public static String getString(JSONObject jsonObject, String key, String defaultValue) { if (jsonObject == null || StringUtils.isEmpty(key)) { return defaultValue; } try { return jsonObject.getString(key); } catch (JSONException e) { if (isPrintException) { e.printStackTrace(); } return defaultValue; } } /** * get String from jsonData * * @param jsonData * @param key * @param defaultValue * @return <ul> * <li>if jsonObject is null, return defaultValue</li> * <li>if jsonData {@link JSONObject#JSONObject(String)} exception, return defaultValue</li> * <li>return {@link JSONUtils#getString(JSONObject, String, String)}</li> * </ul> */ public static String getString(String jsonData, String key, String defaultValue) { if (StringUtils.isEmpty(jsonData)) { return defaultValue; } try { JSONObject jsonObject = new JSONObject(jsonData); return getString(jsonObject, key, defaultValue); } catch (JSONException e) { if (isPrintException) { e.printStackTrace(); } return defaultValue; } } /** * get String from jsonObject * * @param jsonObject * @param defaultValue * @param keyArray * @return <ul> * <li>if jsonObject is null, return defaultValue</li> * <li>if keyArray is null or empty, return defaultValue</li> * <li>get {@link #getJSONObject(JSONObject, String, JSONObject)} by recursion, return it. if anyone is * null, return directly</li> * </ul> */ public static String getStringCascade(JSONObject jsonObject, String defaultValue, String... keyArray) { if (jsonObject == null || keyArray == null || keyArray.length == 0) { return defaultValue; } String data = jsonObject.toString(); for (String key : keyArray) { data = getStringCascade(data, key, defaultValue); if (data == null) { return defaultValue; } } return data; } /** * get String from jsonData * * @param jsonData * @param defaultValue * @param keyArray * @return <ul> * <li>if jsonData is null, return defaultValue</li> * <li>if keyArray is null or empty, return defaultValue</li> * <li>get {@link #getJSONObject(JSONObject, String, JSONObject)} by recursion, return it. if anyone is * null, return directly</li> * </ul> */ public static String getStringCascade(String jsonData, String defaultValue, String... keyArray) { if (StringUtils.isEmpty(jsonData)) { return defaultValue; } String data = jsonData; for (String key : keyArray) { data = getString(data, key, defaultValue); if (data == null) { return defaultValue; } } return data; } /** * get String array from jsonObject * * @param jsonObject * @param key * @param defaultValue * @return <ul> * <li>if jsonObject is null, return defaultValue</li> * <li>if key is null or empty, return defaultValue</li> * <li>if {@link JSONObject#getJSONArray(String)} exception, return defaultValue</li> * <li>if {@link JSONArray#getString(int)} exception, return defaultValue</li> * <li>return string array</li> * </ul> */ public static String[] getStringArray(JSONObject jsonObject, String key, String[] defaultValue) { if (jsonObject == null || StringUtils.isEmpty(key)) { return defaultValue; } try { JSONArray statusArray = jsonObject.getJSONArray(key); if (statusArray != null) { String[] value = new String[statusArray.length()]; for (int i = 0; i < statusArray.length(); i++) { value[i] = statusArray.getString(i); } return value; } } catch (JSONException e) { if (isPrintException) { e.printStackTrace(); } return defaultValue; } return defaultValue; } /** * get String array from jsonData * * @param jsonData * @param key * @param defaultValue * @return <ul> * <li>if jsonObject is null, return defaultValue</li> * <li>if jsonData {@link JSONObject#JSONObject(String)} exception, return defaultValue</li> * <li>return {@link JSONUtils#getStringArray(JSONObject, String, String[])}</li> * </ul> */ public static String[] getStringArray(String jsonData, String key, String[] defaultValue) { if (StringUtils.isEmpty(jsonData)) { return defaultValue; } try { JSONObject jsonObject = new JSONObject(jsonData); return getStringArray(jsonObject, key, defaultValue); } catch (JSONException e) { if (isPrintException) { e.printStackTrace(); } return defaultValue; } } /** * get String list from jsonObject * * @param jsonObject * @param key * @param defaultValue * @return <ul> * <li>if jsonObject is null, return defaultValue</li> * <li>if key is null or empty, return defaultValue</li> * <li>if {@link JSONObject#getJSONArray(String)} exception, return defaultValue</li> * <li>if {@link JSONArray#getString(int)} exception, return defaultValue</li> * <li>return string array</li> * </ul> */ public static List<String> getStringList(JSONObject jsonObject, String key, List<String> defaultValue) { if (jsonObject == null || StringUtils.isEmpty(key)) { return defaultValue; } try { JSONArray statusArray = jsonObject.getJSONArray(key); if (statusArray != null) { List<String> list = new ArrayList<String>(); for (int i = 0; i < statusArray.length(); i++) { list.add(statusArray.getString(i)); } return list; } } catch (JSONException e) { if (isPrintException) { e.printStackTrace(); } return defaultValue; } return defaultValue; } /** * get String list from jsonData * * @param jsonData * @param key * @param defaultValue * @return <ul> * <li>if jsonObject is null, return defaultValue</li> * <li>if jsonData {@link JSONObject#JSONObject(String)} exception, return defaultValue</li> * <li>return {@link JSONUtils#getStringList(JSONObject, String, List)}</li> * </ul> */ public static List<String> getStringList(String jsonData, String key, List<String> defaultValue) { if (StringUtils.isEmpty(jsonData)) { return defaultValue; } try { JSONObject jsonObject = new JSONObject(jsonData); return getStringList(jsonObject, key, defaultValue); } catch (JSONException e) { if (isPrintException) { e.printStackTrace(); } return defaultValue; } } /** * get JSONObject from jsonObject * * @param jsonObject * @param key * @param defaultValue * @return <ul> * <li>if jsonObject is null, return defaultValue</li> * <li>if key is null or empty, return defaultValue</li> * <li>if {@link JSONObject#getJSONObject(String)} exception, return defaultValue</li> * <li>return {@link JSONObject#getJSONObject(String)}</li> * </ul> */ public static JSONObject getJSONObject(JSONObject jsonObject, String key, JSONObject defaultValue) { if (jsonObject == null || StringUtils.isEmpty(key)) { return defaultValue; } try { return jsonObject.getJSONObject(key); } catch (JSONException e) { if (isPrintException) { e.printStackTrace(); } return defaultValue; } } /** * get JSONObject from jsonData * * @param jsonData * @param key * @param defaultValue * @return <ul> * <li>if jsonData is null, return defaultValue</li> * <li>if jsonData {@link JSONObject#JSONObject(String)} exception, return defaultValue</li> * <li>return {@link JSONUtils#getJSONObject(JSONObject, String, JSONObject)}</li> * </ul> */ public static JSONObject getJSONObject(String jsonData, String key, JSONObject defaultValue) { if (StringUtils.isEmpty(jsonData)) { return defaultValue; } try { JSONObject jsonObject = new JSONObject(jsonData); return getJSONObject(jsonObject, key, defaultValue); } catch (JSONException e) { if (isPrintException) { e.printStackTrace(); } return defaultValue; } } /** * get JSONObject from jsonObject * * @param jsonObject * @param defaultValue * @param keyArray * @return <ul> * <li>if jsonObject is null, return defaultValue</li> * <li>if keyArray is null or empty, return defaultValue</li> * <li>get {@link #getJSONObject(JSONObject, String, JSONObject)} by recursion, return it. if anyone is * null, return directly</li> * </ul> */ public static JSONObject getJSONObjectCascade(JSONObject jsonObject, JSONObject defaultValue, String... keyArray) { if (jsonObject == null || keyArray == null || keyArray.length == 0) { return defaultValue; } JSONObject js = jsonObject; for (String key : keyArray) { js = getJSONObject(js, key, defaultValue); if (js == null) { return defaultValue; } } return js; } /** * get JSONObject from jsonData * * @param jsonData * @param defaultValue * @param keyArray * @return <ul> * <li>if jsonData is null, return defaultValue</li> * <li>if keyArray is null or empty, return defaultValue</li> * <li>get {@link #getJSONObject(JSONObject, String, JSONObject)} by recursion, return it. if anyone is * null, return directly</li> * </ul> */ public static JSONObject getJSONObjectCascade(String jsonData, JSONObject defaultValue, String... keyArray) { if (StringUtils.isEmpty(jsonData)) { return defaultValue; } try { JSONObject jsonObject = new JSONObject(jsonData); return getJSONObjectCascade(jsonObject, defaultValue, keyArray); } catch (JSONException e) { if (isPrintException) { e.printStackTrace(); } return defaultValue; } } /** * get JSONArray from jsonObject * * @param jsonObject * @param key * @param defaultValue * @return <ul> * <li>if jsonObject is null, return defaultValue</li> * <li>if key is null or empty, return defaultValue</li> * <li>if {@link JSONObject#getJSONArray(String)} exception, return defaultValue</li> * <li>return {@link JSONObject#getJSONArray(String)}</li> * </ul> */ public static JSONArray getJSONArray(JSONObject jsonObject, String key, JSONArray defaultValue) { if (jsonObject == null || StringUtils.isEmpty(key)) { return defaultValue; } try { return jsonObject.getJSONArray(key); } catch (JSONException e) { if (isPrintException) { e.printStackTrace(); } return defaultValue; } } /** * get JSONArray from jsonData * * @param jsonData * @param key * @param defaultValue * @return <ul> * <li>if jsonObject is null, return defaultValue</li> * <li>if jsonData {@link JSONObject#JSONObject(String)} exception, return defaultValue</li> * <li>return {@link JSONUtils#getJSONArray(JSONObject, String, JSONObject)}</li> * </ul> */ public static JSONArray getJSONArray(String jsonData, String key, JSONArray defaultValue) { if (StringUtils.isEmpty(jsonData)) { return defaultValue; } try { JSONObject jsonObject = new JSONObject(jsonData); return getJSONArray(jsonObject, key, defaultValue); } catch (JSONException e) { if (isPrintException) { e.printStackTrace(); } return defaultValue; } } /** * get Boolean from jsonObject * * @param jsonObject * @param key * @param defaultValue * @return <ul> * <li>if jsonObject is null, return defaultValue</li> * <li>if key is null or empty, return defaultValue</li> * <li>return {@link JSONObject#getBoolean(String)}</li> * </ul> */ public static boolean getBoolean(JSONObject jsonObject, String key, Boolean defaultValue) { if (jsonObject == null || StringUtils.isEmpty(key)) { return defaultValue; } try { return jsonObject.getBoolean(key); } catch (JSONException e) { if (isPrintException) { e.printStackTrace(); } return defaultValue; } } /** * get Boolean from jsonData * * @param jsonData * @param key * @param defaultValue * @return <ul> * <li>if jsonObject is null, return defaultValue</li> * <li>if jsonData {@link JSONObject#JSONObject(String)} exception, return defaultValue</li> * <li>return {@link JSONUtils#getBoolean(JSONObject, String, Boolean)}</li> * </ul> */ public static boolean getBoolean(String jsonData, String key, Boolean defaultValue) { if (StringUtils.isEmpty(jsonData)) { return defaultValue; } try { JSONObject jsonObject = new JSONObject(jsonData); return getBoolean(jsonObject, key, defaultValue); } catch (JSONException e) { if (isPrintException) { e.printStackTrace(); } return defaultValue; } } /** * get map from jsonObject. * * @param jsonObject key-value pairs json * @param key * @return <ul> * <li>if jsonObject is null, return null</li> * <li>return {@link JSONUtils#parseKeyAndValueToMap(String)}</li> * </ul> */ public static Map<String, String> getMap(JSONObject jsonObject, String key) { return JSONUtils.parseKeyAndValueToMap(JSONUtils.getString(jsonObject, key, null)); } /** * get map from jsonData. * * @param jsonData key-value pairs string * @param key * @return <ul> * <li>if jsonData is null, return null</li> * <li>if jsonData length is 0, return empty map</li> * <li>if jsonData {@link JSONObject#JSONObject(String)} exception, return null</li> * <li>return {@link JSONUtils#getMap(JSONObject, String)}</li> * </ul> */ public static Map<String, String> getMap(String jsonData, String key) { if (jsonData == null) { return null; } if (jsonData.length() == 0) { return new HashMap<String, String>(); } try { JSONObject jsonObject = new JSONObject(jsonData); return getMap(jsonObject, key); } catch (JSONException e) { if (isPrintException) { e.printStackTrace(); } return null; } } /** * parse key-value pairs to map. ignore empty key, if getValue exception, put empty value * * @param sourceObj key-value pairs json * @return <ul> * <li>if sourceObj is null, return null</li> * <li>else parse entry one by one</li> * </ul> */ @SuppressWarnings("rawtypes") public static Map<String, String> parseKeyAndValueToMap(JSONObject sourceObj) { if (sourceObj == null) { return null; } Map<String, String> keyAndValueMap = new HashMap<String, String>(); for (Iterator iter = sourceObj.keys(); iter.hasNext();) { String key = (String) iter.next(); keyAndValueMap.put(key, getString(sourceObj, key, "")); } return keyAndValueMap; } /** * parse key-value pairs to map. ignore empty key, if getValue exception, put empty value * * @param source key-value pairs json * @return <ul> * <li>if source is null or source's length is 0, return empty map</li> * <li>if source {@link JSONObject#JSONObject(String)} exception, return null</li> * <li>return {@link JSONUtils#parseKeyAndValueToMap(JSONObject)}</li> * </ul> */ public static Map<String, String> parseKeyAndValueToMap(String source) { if (StringUtils.isEmpty(source)) { return null; } try { JSONObject jsonObject = new JSONObject(source); return parseKeyAndValueToMap(jsonObject); } catch (JSONException e) { if (isPrintException) { e.printStackTrace(); } return null; } } public static <T> T parseJson(String jsonString, Class<T> clazz) { T t = null; try { Gson gson = new Gson(); t = gson.fromJson(jsonString, clazz); } catch (Exception e) { e.printStackTrace(); System.out.println("?json"); } return t; } }