Json解析示例

import java.lang.reflect.Field;import java.lang.reflect.Modifier;import java.util.ArrayList;import java.util.HashMap;import java.util.List;import java.util.Map;import org.json.JSONArray;import org.json.JSONException;import org.json.JSONObject;import android.util.Log;/** * JSON数据解析工具类，用于将JSON字符串转换成指定的对象或对象List，以及Map或包含Map的List *  * @author Li Bin */public class JsonUtil<T> {private static final String LOG_JSON_ERROR = "com.imcore.common.util.JsonError";private static final String BYTE = "java.lang.Byte";private static final String INTEGER = "java.lang.Integer";private static final String SHORT = "java.lang.Short";private static final String LONG = "java.lang.Long";private static final String BOOLEAN = "java.lang.Boolean";private static final String CHAR = "java.lang.Character";private static final String FLOAT = "java.lang.Float";private static final String DOUBLE = "java.lang.Double";private static final String VALUE_BYTE = "byte";private static final String VALUE_INTEGER = "int";private static final String VALUE_SHORT = "short";private static final String VALUE_LONG = "long";private static final String VALUE_BOOLEAN = "boolean";private static final String VALUE_CHAR = "char";private static final String VALUE_FLOAT = "float";private static final String VALUE_DOUBLE = "double";/** * 根据key获取给定的json数据的值 *  * @param json *            给定的JSON字符串 * @param key *            指定的要获取值所对应的key * @return 返回一个字符串，表示根据指定的key所得到的值，获取失败或发生JSON解析错误则返回空字符串 */public static String getJsonValueByKey(String json, String key) {String value = "";try {JSONObject jo = new JSONObject(json);value = jo.getString(key);} catch (JSONException e) {Log.e(LOG_JSON_ERROR, e.getLocalizedMessage());}return value;}/** * 将指定的JSON字符串转换成cls指定的类的实例对象 *  * @param json *            给定的JSON字符串 * @param cls *            指定要转换成的对象所属的类型Class实例 * @return 返回cls指定类型的对象实例,其中的字段与json数据键值对一一对应 */public static <T> T toObject(String json, Class<T> cls) {T obj = null;try {JSONObject jsonObject = new JSONObject(json);obj = cls.newInstance();Field[] fields = cls.getDeclaredFields();for (Field field : fields) {if (Modifier.isFinal(field.getModifiers())|| Modifier.isPrivate(field.getModifiers())) {continue;}try {String key = field.getName();if (jsonObject.get(key) == JSONObject.NULL) {field.set(obj, null);} else {Object value = getValue4Field(jsonObject.get(key),jsonObject.get(key).getClass().getName());field.set(obj, value);}} catch (JSONException e) {field.set(obj, null);}}} catch (Exception e) {e.printStackTrace();Log.e(LOG_JSON_ERROR, e.getLocalizedMessage());}return obj;}/** * 把指定的对象orginalValue转换成typeName指定的类型的对象 *  * @param orginalValue *            对象在转换之前的值 * @param fieldType *            要转换的类型名称 * @return */private static Object getValue4Field(Object orginalValue, String typeName) {Log.i("YunMing", typeName);Object value = orginalValue.toString();if (typeName.equals(BYTE) || typeName.equals(VALUE_BYTE)) {value = Byte.class.cast(orginalValue);}if (typeName.equals(INTEGER) || typeName.equals(VALUE_INTEGER)) {value = Integer.class.cast(orginalValue);}if (typeName.equals(SHORT) || typeName.equals(VALUE_SHORT)) {value = Short.class.cast(orginalValue);}if (typeName.equals(LONG) || typeName.equals(VALUE_LONG)) {value = Long.class.cast(orginalValue);}if (typeName.equals(BOOLEAN) || typeName.equals(VALUE_BOOLEAN)) {value = Boolean.class.cast(orginalValue);}if (typeName.equals(CHAR) || typeName.equals(VALUE_CHAR)) {value = Character.class.cast(orginalValue);}if (typeName.equals(FLOAT) || typeName.equals(VALUE_FLOAT)) {value = Float.class.cast(orginalValue);}if (typeName.equals(DOUBLE) || typeName.equals(VALUE_DOUBLE)) {value = Double.class.cast(orginalValue);}return value;}/** * 将指定的JSON字符串转换成包含cls指定的类型的实体对象List集合 *  * @param json *            给定的JSON字符串 * @param cls *            指定要转换成的对象所属的类型Class实例 * @return 返回一个List集合，其中包含json中的数据元素所对应的实体对象实例 */public static <T> List<T> toObjectList(String json, Class<T> cls) {List<T> list = new ArrayList<T>();try {List<String> jsonStrList = toJsonStrList(json);for (String jsonStr : jsonStrList) {T obj = toObject(jsonStr, cls);list.add(obj);}} catch (Exception e) {e.printStackTrace();Log.e(LOG_JSON_ERROR, e.getLocalizedMessage());}return list;}/** * 将一个数组型json字符串转换成包含子json字符串的List集合 *  * @param json *            给定的JSON字符串 * @return 返回一个List集合，包含一组字符串，对应于给定原始JSON数据内元素的字符串形式 */public static List<String> toJsonStrList(String json) {List<String> strList = new ArrayList<String>();try {JSONArray jsonArray = new JSONArray(json);for (int i = 0; i < jsonArray.length(); i++) {String jsonStr = jsonArray.getString(i);strList.add(jsonStr);}} catch (JSONException e) {Log.e(LOG_JSON_ERROR, e.getMessage());}return strList;}/** * 将json字符串转换为Map *  * @param json * @return */public static Map<String, Object> toMap(String json) {Map<String, Object> map = null;try {JSONObject jo = new JSONObject(json);map = convertJSONObjectToMap(jo);} catch (Exception e) {Log.e(LOG_JSON_ERROR, e.getMessage());}return map;}/** * 将json字符串转换为包含Map的List集合 *  * @param json * @return */public static List<Map<String, Object>> toMapList(String json) {List<Map<String, Object>> mapList = new ArrayList<Map<String, Object>>();try {JSONArray jsonArray = new JSONArray(json);for (int i = 0; i < jsonArray.length(); i++) {JSONObject jo = jsonArray.getJSONObject(i);Map<String, Object> map = convertJSONObjectToMap(jo);mapList.add(map);}} catch (JSONException e) {Log.e(LOG_JSON_ERROR, e.getMessage());}return mapList;}/** * 将一个JSONObject对象转换为Map *  * @param jo * @return * @throws JSONException */private static Map<String, Object> convertJSONObjectToMap(JSONObject jo)throws JSONException {Map<String, Object> map = new HashMap<String, Object>();JSONObject newJo = mergeJsonNodes(jo);JSONArray names = newJo.names();for (int i = 0; i < names.length(); i++) {String key = names.getString(i);Object value = newJo.get(key);if ((value != null) && (!value.toString().equals(""))&& (!value.toString().equals("null"))) {map.put(key, value);}}return map;}/** * 将JSON对象的非一阶子结点与一阶结点合并 *  * @param oldJo *            包含非一阶结点的Json对象 * @return 返回合并之后的，只包含一阶结点的Json对象 */private static JSONObject mergeJsonNodes(JSONObject oldJo)throws JSONException {JSONObject newJo = oldJo;JSONArray names = newJo.names();List<String> delKeys = new ArrayList<String>(); // 待删除的非一阶结点的Json对象的key// 找出需要合并的子结点的keyfor (int i = 0; i < names.length(); i++) {String key = names.getString(i);if (newJo.optJSONObject(key) != null) {delKeys.add(key);}}// 合并找到的子结点与一阶结点，并删除原先的子结点for (String key : delKeys) {JSONObject subJo = newJo.getJSONObject(key);subJo = mergeJsonNodes(subJo); // 递归整理子结点的所有子结点newJo = merge(newJo, subJo);newJo.remove(key);}return newJo;}/** * 合并两个JSON对象 *  * @param jo1 * @param jo2 * @return 返回合并之后的JSON对象 */private static JSONObject merge(JSONObject jo1, JSONObject jo2)throws JSONException {JSONObject newJo = jo1;JSONArray names = jo2.names();for (int i = 0; i < names.length(); i++) {String key = names.getString(i);newJo.put(key, jo2.get(key));}return newJo;}/** * 判断一个JSON字符串是否是空数据 *  * @param json * @return */public static boolean isJsonNull(String json) {if (json == null || json.equals("") || json.equals("null")|| json.equals("{}") || json.equals("[]")) {return true;} else {return false;}}}