SharedPreferencesUtil工具类
//每个app 都会有一些信息，需要储存在本地,这个时候就用到 sharedPreferences来保存，是android 多种储存方式中的一种，
记得有次面试 ，面试管问我 sharedPreferences 和 数据库储存的区别， 我当时回答是, sharedPreferences 储存的数据量小一点 但是读取很快，而后者则 储存数据大的时候会用到。
这是一个工具类
/**
*
* SharedPreferences 工具类
*/
public class SharedPreferencesUtil {
private static SharedPreferencesUtil util;
private static SharedPreferences sp;
private SharedPreferencesUtil(Context context, String name) {
sp = context.getSharedPreferences(name, Context.MODE_PRIVATE);
}
/**
* 初始化SharedPreferencesUtil,只需要初始化一次，建议在Application中初始化
*
* @param context 上下文对象
* @param name SharedPreferences Name
*/
public static void getInstance(Context context, String name) {
if (util == null) {
util = new SharedPreferencesUtil(context, name);
}
}
/**
* 保存数据到SharedPreferences
*
* @param key 键
* @param value 需要保存的数据
* @return 保存结果
*/
public static boolean putData(String key, Object value) {
boolean result;
SharedPreferences.Editor editor = sp.edit();
String type = value.getClass().getSimpleName();
try {
switch (type) {
case "Boolean":
editor.putBoolean(key, (Boolean) value);
break;
case "Long":
editor.putLong(key, (Long) value);
break;
case "Float":
editor.putFloat(key, (Float) value);
break;
case "String":
editor.putString(key, (String) value);
break;
case "Integer":
editor.putInt(key, (Integer) value);
break;
default:
Gson gson = new Gson();
String json = gson.toJson(value);
editor.putString(key, json);
break;
}
result = true;
} catch (Exception e) {
result = false;
e.printStackTrace();
}
editor.apply();
return result;
}
/**
* 获取SharedPreferences中保存的数据
*
* @param key 键
* @param defaultValue 获取失败默认值
* @return 从SharedPreferences读取的数据
*/
public static Object getData(String key, Object defaultValue) {
Object result;
String type = defaultValue.getClass().getSimpleName();
try {
switch (type) {
case "Boolean":
result = sp.getBoolean(key, (Boolean) defaultValue);
break;
case "Long":
result = sp.getLong(key, (Long) defaultValue);
break;
case "Float":
result = sp.getFloat(key, (Float) defaultValue);
break;
case "String":
result = sp.getString(key, (String) defaultValue);
break;
case "Integer":
result = sp.getInt(key, (Integer) defaultValue);
break;
default:
Gson gson = new Gson();
String json = sp.getString(key, "");
if (!json.equals("") && json.length() > 0) {
result = gson.fromJson(json, defaultValue.getClass());
} else {
result = defaultValue;
}
break;
}
} catch (Exception e) {
result = null;
e.printStackTrace();
}
return result;
}
/**
* 用于保存集合
*
* @param key key
* @param list 集合数据
* @return 保存结果
*/
public static boolean putListData(String key, List list) {
boolean result;
String type = list.get(0).getClass().getSimpleName();
SharedPreferences.Editor editor = sp.edit();
JsonArray array = new JsonArray();
try {
switch (type) {
case "Boolean":
for (int i = 0; i < list.size(); i++) {
array.add((Boolean) list.get(i));
}
break;
case "Long":
for (int i = 0; i < list.size(); i++) {
array.add((Long) list.get(i));
}
break;
case "Float":
for (int i = 0; i < list.size(); i++) {
array.add((Float) list.get(i));
}
break;
case "String":
for (int i = 0; i < list.size(); i++) {
array.add((String) list.get(i));
}
break;
case "Integer":
for (int i = 0; i < list.size(); i++) {
array.add((Integer) list.get(i));
}
break;
default:
Gson gson = new Gson();
for (int i = 0; i < list.size(); i++) {
JsonElement obj = gson.toJsonTree(list.get(i));
array.add(obj);
}
break;
}
editor.putString(key, array.toString());
result = true;
} catch (Exception e) {
result = false;
e.printStackTrace();
}
editor.apply();
return result;
}
/**
* 获取保存的List
*
* @param key key
* @return 对应的Lis集合
*/
public static List getListData(String key, Class cls) {
List list = new ArrayList<>();
String json = sp.getString(key, "");
if (!json.equals("") && json.length() > 0) {
Gson gson = new Gson();
JsonArray array = new JsonParser().parse(json).getAsJsonArray();
for (JsonElement elem : array) {
list.add(gson.fromJson(elem, cls));
}
}
return list;
}
/**
* 用于保存集合
*
* @param key key
* @param map map数据
* @return 保存结果
*/
public static boolean putHashMapData(String key, Map map) {
boolean result;
SharedPreferences.Editor editor = sp.edit();
try {
Gson gson = new Gson();
String json = gson.toJson(map);
editor.putString(key, json);
result = true;
} catch (Exception e) {
result = false;
e.printStackTrace();
}
editor.apply();
return result;
}
/**
* 用于保存集合
*
* @param key key
* @return HashMap
*/
public static HashMap getHashMapData(String key, Class clsV) {
String json = sp.getString(key, "");
HashMap map = new HashMap<>();
Gson gson = new Gson();
JsonObject obj = new JsonParser().parse(json).getAsJsonObject();
Set> entrySet = obj.entrySet();
for (Map.Entry entry : entrySet) {
String entryKey = entry.getKey();
JsonObject value = (JsonObject) entry.getValue();
map.put(entryKey, gson.fromJson(value, clsV));
}
Log.e("SharedPreferencesUtil", obj.toString());
return map;
}
}