Android(安卓)SharedPreferences工具类 ，实现List/Map的保存读取
16lz
2021-01-26
转载请注明出处：http://blog.csdn.net/a512337862/article/details/73633420
最近因为需要将List集合和Map集合的数据保存到SharedPreferences中，所以对以前自己封装的SharedPreferencesUtil进行了修改，在原有的保存读Integer，String，Float，Long，Boolean，Object的基础上增加了保存读取List
SharedPreferencesUtil
代码
/** * Created by ZhangHao on 2016/6/21. * 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; }} SharedPreferences是无法直接保存Object,List集合和Map集合的，需要先将它们转换为字符串，在保存到SharedPreferences中，取得时候再把对应的字符串转为Object,List集合或者Map集合。
我这里的做法是利用Gson将Object,List或者Map转成Json保存到SharedPreferences中，取数据的时候再通过Gson将json数据转成Object,List集合或者Map集合。
使用步骤
1、初始化：
2、保存常规数据：
3、读取常规数据 :
4、保存List集合：
5、读取List集合：
6.保存Map集合：
7、读取Map集合：
Demo
SharedPreferencesUtil的使用方法十分简单，基本上不需要Demo就能直接使用。但这里还是把demo代码贴一下，觉得没必要的可以直接略过：
Activity
/** * Created by ZhangHao on 2017/6/23. * 用来测试SharedPreferencesUtil工具类 */public class SpActivity extends AppCompatActivity { @BindView(R.id.boolean_check) CheckBox booleanCheck; @BindView(R.id.int_input) EditText intInput; @BindView(R.id.text_input) EditText textInput; @BindView(R.id.float_input) EditText floatInput; @BindView(R.id.long_input) EditText longInput; @BindView(R.id.showResult) TextView showResult; private String intKey = "intKey"; private String stringKey = "stringKey"; private String floatKey = "floatKey"; private String longKey = "longKey"; private String booleanKey = "booleanKey"; private String beanKey = "beanKey"; private String hunmansKey = "hunmansKey"; private String intsKey = "intsKey"; private String strsKey = "strsKey"; private String mapKey = "mapKey"; private HumanBean bean; //List private List integers = new ArrayList<>(); private List humanBeens = new ArrayList<>(); private List strings = new ArrayList<>(); //Map private Map map = new HashMap<>(); @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_sp); ButterKnife.bind(this); //初始化HumanBean bean = new HumanBean(true, 20, "Black_Hao", 24f, "男", System.currentTimeMillis() , new SchoolBean("AnHui", 20, System.currentTimeMillis(), false)); } public void onClick(View view) { switch (view.getId()) { case R.id.save_input: //保存从EditText输入的常规数据到sp boolean bool = booleanCheck.isChecked(); String str = textInput.getText().toString().trim(); int in = Integer.parseInt(intInput.getText().toString()); float f = Float.parseFloat(floatInput.getText().toString().trim()); long lo = Long.parseLong(longInput.getText().toString().trim()); boolean resultBol = SharedPreferencesUtil.putData(booleanKey, bool); boolean resultInt = SharedPreferencesUtil.putData(intKey, in); boolean resultStr = SharedPreferencesUtil.putData(stringKey, str); boolean resultFlo = SharedPreferencesUtil.putData(floatKey, f); boolean resultLon = SharedPreferencesUtil.putData(longKey, lo); boolean resultBea = SharedPreferencesUtil.putData(beanKey, bean); showResult.setText("resultBol:---" + resultBol + " \nresultInt:--- " + resultInt + " \nresultStr:--- " + resultStr + " \nresultFlo:--- " + resultFlo + " \nresultLon:--- " + resultLon + " \nresultBea --- " + resultBea); break; case R.id.get_input: //读取常规数据并显示到showResult boolean Bol = (boolean) SharedPreferencesUtil.getData(booleanKey, false); int Int = (int) SharedPreferencesUtil.getData(intKey, -1); String Str = (String) SharedPreferencesUtil.getData(stringKey, ""); float Flo = (float) SharedPreferencesUtil.getData(floatKey, 0f); long Lon = (long) SharedPreferencesUtil.getData(longKey, 1L); HumanBean Bea = (HumanBean) SharedPreferencesUtil.getData(beanKey, bean); showResult.setText(Bol + " \n " + Int + " \n " + Str + " \n " + Flo + " \n " + Lon + " \n " + Bea.toString()); break; case R.id.save_list: //保存List数据到SharedPreferences getDefaultList(); boolean resultInts = SharedPreferencesUtil.putListData(intsKey, integers); boolean resultBeans = SharedPreferencesUtil.putListData(hunmansKey, humanBeens); boolean resultStrs = SharedPreferencesUtil.putListData(strsKey, strings); showResult.setText("resultInts:---" + resultInts + "\nresultBeans:---" + resultBeans + "\nresultStrs:---" + resultStrs); break; case R.id.get_list: 读取Map数据并显示到showResult integers.clear(); humanBeens.clear(); strings.clear(); integers.addAll(SharedPreferencesUtil.getListData(intsKey, Integer.class)); humanBeens.addAll(SharedPreferencesUtil.getListData(hunmansKey, HumanBean.class)); strings.addAll(SharedPreferencesUtil.getListData(strsKey, String.class)); //遍历integers并将结果打印 String intsStr = "{"; for (int i = 0; i < integers.size(); i++) { intsStr += integers.get(i) + " --- "; } intsStr += "}"; //遍历humanBeens并将结果打印 String humsStr = ""; for (int i = 0; i < humanBeens.size(); i++) { humsStr += humanBeens.get(i).toString() + "\n"; } //遍历strings并将结果打印 String strs = "{"; for (int i = 0; i < strings.size(); i++) { strs += strings.get(i) + " ---- "; } strs += "}"; showResult.setText(intsStr + "\n" + humsStr + "\n" + strs); break; case R.id.save_map: //保存Map数据到SharedPreferences getDefaultList(); boolean resultMap = SharedPreferencesUtil.putHashMapData(mapKey, map); showResult.setText("resultMap:---" + resultMap); break; case R.id.get_map: //读取Map数据并显示到showResult map.clear(); map.putAll(SharedPreferencesUtil.getHashMapData(mapKey, HumanBean.class)); //遍历map并将结果打印 String mapStr = ""; for (String key : map.keySet()) { mapStr += key + " : " + map.get(key).toString() + "\n"; } showResult.setText(mapStr); break; } } /** * 生成默认数据以保存到SharedPreferences */ private void getDefaultList() { integers.clear(); humanBeens.clear(); strings.clear(); String[] names = new String[]{"Black_Hao", "White_Hao", "Gray_Hao", "Blue_Hao"}; Random random = new Random(); for (int i = 0; i < 20; i++) { int s = random.nextInt(100); integers.add(s); humanBeens.add(new HumanBean(s % 2 == 0, s, names[s % 4], 24f, "男", System.currentTimeMillis() , new SchoolBean("AnHui", 20, System.currentTimeMillis(), s % 3 == 0))); strings.add(names[s % 4]); map.put(strings.get(i) + i, humanBeens.get(i)); } }} Layout
<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical"> <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="horizontal"> <CheckBox android:id="@+id/boolean_check" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center_vertical" android:layout_marginStart="5dp" android:checked="true" /> <EditText android:id="@+id/int_input" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_marginStart="5dp" android:layout_weight="1" android:hint="Integer" android:inputType="number" /> <EditText android:id="@+id/text_input" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_marginStart="5dp" android:layout_weight="1" android:hint="String" android:inputType="text" /> <EditText android:id="@+id/float_input" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_marginStart="5dp" android:layout_weight="1" android:hint="Float" android:inputType="number" /> <EditText android:id="@+id/long_input" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_marginStart="5dp" android:layout_weight="1" android:hint="Long" android:inputType="number" /> LinearLayout> <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="5dp" android:orientation="horizontal"> <Button android:id="@+id/save_input" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginStart="5dp" android:onClick="onClick" android:text="SaveBasic" /> <Button android:id="@+id/get_input" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginStart="5dp" android:onClick="onClick" android:text="GetBasic" /> <Button android:id="@+id/save_list" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginStart="5dp" android:onClick="onClick" android:text="SaveList" /> <Button android:id="@+id/get_list" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginStart="5dp" android:onClick="onClick" android:text="ReadList" /> <Button android:id="@+id/save_map" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginStart="5dp" android:onClick="onClick" android:text="SaveMap" /> <Button android:id="@+id/get_map" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginStart="5dp" android:onClick="onClick" android:text="ReadMap" /> LinearLayout> <TextView android:id="@+id/showResult" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_margin="5dp" />LinearLayout>Application
这里Application只做了初始化SharedPreferencesUtil的操作
/** * Created by ZhangHao on 2017/6/23. */public class HaoApp extends Application { @Override public void onCreate() { super.onCreate(); SharedPreferencesUtil.getInstance(this, "Test"); }}自定义实体类
为了测试Object保存读取，自定义两个简单的实体类
HumanBean
/** * Created by ZhangHao on 2017/6/23. * 用来测试SharedPreferencesUtil */public class HumanBean { private boolean isTest; private int num; private String name; private String sex; private float age; private long time; private SchoolBean bean; private List family; public HumanBean(boolean isTest, int num, String name, float age, String sex, long time, SchoolBean bean) { this.isTest = isTest; this.num = num; this.name = name; this.age = age; this.sex = sex; this.time = time; this.bean = bean; family = new ArrayList<>(); family.add("Father"); family.add("Mother"); family.add("Sister"); family.add("Brother"); family.add("Self"); } public boolean isTest() { return isTest; } public void setTest(boolean test) { isTest = test; } public int getNum() { return num; } public void setNum(int num) { this.num = num; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getSex() { return sex; } public void setSex(String sex) { this.sex = sex; } public float getAge() { return age; } public void setAge(float age) { this.age = age; } public long getTime() { return time; } public void setTime(long time) { this.time = time; } public SchoolBean getBean() { return bean; } public void setBean(SchoolBean bean) { this.bean = bean; } @Override public String toString() { return "HumanBean{" + "isTest=" + isTest + ", num=" + num + ", name='" + name + '\'' + ", sex='" + sex + '\'' + ", age=" + age + ", time=" + time + ", bean=" + bean + ", family=" + family + '}'; }} SchoolBean
/** * Created by ZhangHao on 2017/6/23. * 用来测试SharedPreferencesUtil */public class SchoolBean { private String homeAddr; private int grade; private long schoolTime; private boolean isBoarding; private List students; public SchoolBean(String homeAddr, int grade, long schoolTime, boolean isBoarding) { this.homeAddr = homeAddr; this.grade = grade; this.schoolTime = schoolTime; this.isBoarding = isBoarding; students = new ArrayList<>(); students.add(15); students.add(105); students.add(150); } public String getHomeAddr() { return homeAddr; } public void setHomeAddr(String homeAddr) { this.homeAddr = homeAddr; } public int getGrade() { return grade; } public void setGrade(int grade) { this.grade = grade; } public long getSchoolTime() { return schoolTime; } public void setSchoolTime(long schoolTime) { this.schoolTime = schoolTime; } public boolean isBoarding() { return isBoarding; } public void setBoarding(boolean boarding) { isBoarding = boarding; } @Override public String toString() { return "SchoolBean{" + "homeAddr='" + homeAddr + '\'' + ", grade=" + grade + ", schoolTime=" + schoolTime + ", isBoarding=" + isBoarding + ", students=" + students + '}'; }} 结语
1、因为本人文字功底有限，所以介绍性的文字很少，但是基本上每句代码都加了注释，理解起来应该不难，如果有任何问题，可以留言。
2、关于Map的读取暂时只实现Map
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