我需要在许多地方获得用户对象,其中包含许多字段。登录后,我想保存/存储这些用户对象。我们如何实现这种场景?

我不能这样存储它:

SharedPreferences.Editor prefsEditor = myPrefs.edit();
prefsEditor.putString("BusinessUnit", strBusinessUnit);

当前回答

将数据存储在SharedPreference中

SharedPreferences mprefs = getSharedPreferences(AppConstant.PREFS_NAME, MODE_PRIVATE)
mprefs.edit().putString(AppConstant.USER_ID, resUserID).apply();

其他回答

有两个文件解决了共享首选项的所有问题

1)AppPersistence.java

    public class AppPersistence {
    public enum keys {
        USER_NAME, USER_ID, USER_NUMBER, USER_EMAIL, USER_ADDRESS, CITY, USER_IMAGE,
        DOB, MRG_Anniversary, COMPANY, USER_TYPE, support_phone
    }

    private static AppPersistence mAppPersistance;
    private SharedPreferences sharedPreferences;

    public static AppPersistence start(Context context) {
        if (mAppPersistance == null) {
            mAppPersistance = new AppPersistence(context);
        }
        return mAppPersistance;
    }

    private AppPersistence(Context context) {
        sharedPreferences = context.getSharedPreferences(context.getString(R.string.prefrence_file_name),
                Context.MODE_PRIVATE);
    }

    public Object get(Enum key) {
        Map<String, ?> all = sharedPreferences.getAll();
        return all.get(key.toString());
    }

    void save(Enum key, Object val) {
        SharedPreferences.Editor editor = sharedPreferences.edit();
        if (val instanceof Integer) {
            editor.putInt(key.toString(), (Integer) val);
        } else if (val instanceof String) {
            editor.putString(key.toString(), String.valueOf(val));
        } else if (val instanceof Float) {
            editor.putFloat(key.toString(), (Float) val);
        } else if (val instanceof Long) {
            editor.putLong(key.toString(), (Long) val);
        } else if (val instanceof Boolean) {
            editor.putBoolean(key.toString(), (Boolean) val);
        }
        editor.apply();
    }

    void remove(Enum key) {
        SharedPreferences.Editor editor = sharedPreferences.edit();
        editor.remove(key.toString());
        editor.apply();
    }

    public void removeAll() {
        SharedPreferences.Editor editor = sharedPreferences.edit();
        editor.clear();
        editor.apply();
    }
}

2)AppPreference.java

public static void setPreference(Context context, Enum Name, String Value) {
        AppPersistence.start(context).save(Name, Value);
    }

    public static String getPreference(Context context, Enum Name) {
        return (String) AppPersistence.start(context).get(Name);
    }

    public static void removePreference(Context context, Enum Name) {
        AppPersistence.start(context).remove(Name);
    }
}

现在你可以保存,删除或者获取,

保存

AppPreference.setPreference(context, AppPersistence.keys.USER_ID, userID);

删除

AppPreference.removePreference(context, AppPersistence.keys.USER_ID);

-get

 AppPreference.getPreference(context, AppPersistence.keys.USER_ID);

如果你的对象很复杂,我建议序列化/XML/JSON,并将这些内容保存到SD卡。你可以在这里找到关于如何保存到外部存储的其他信息: http://developer.android.com/guide/topics/data/data-storage.html#filesExternal

我知道这个帖子有点旧了。 但我还是要把这个贴出来,希望它能帮助到一些人。 通过将对象序列化为String,可以将任何Object的字段存储为共享首选项。 这里我使用GSON存储共享首选项的任何对象。

保存对象到首选项:

public static void saveObjectToSharedPreference(Context context, String preferenceFileName, String serializedObjectKey, Object object) {
    SharedPreferences sharedPreferences = context.getSharedPreferences(preferenceFileName, 0);
    SharedPreferences.Editor sharedPreferencesEditor = sharedPreferences.edit();
    final Gson gson = new Gson();
    String serializedObject = gson.toJson(object);
    sharedPreferencesEditor.putString(serializedObjectKey, serializedObject);
    sharedPreferencesEditor.apply();
}

从首选项检索对象:

public static <GenericClass> GenericClass getSavedObjectFromPreference(Context context, String preferenceFileName, String preferenceKey, Class<GenericClass> classType) {
    SharedPreferences sharedPreferences = context.getSharedPreferences(preferenceFileName, 0);
    if (sharedPreferences.contains(preferenceKey)) {
        final Gson gson = new Gson();
        return gson.fromJson(sharedPreferences.getString(preferenceKey, ""), classType);
    }
    return null;
}

注意:

记得在gradle的dependencies中添加compile 'com.google.code.gson:gson:2.6.2'。

例子:

//assume SampleClass exists
SampleClass mObject = new SampleObject();

//to store an object
saveObjectToSharedPreference(context, "mPreference", "mObjectKey", mObject);

//to retrive object stored in preference
mObject = getSavedObjectFromPreference(context, "mPreference", "mObjectKey", SampleClass.class);

更新:

正如@Sharp_Edge在评论中指出的那样,上述解决方案不适用于List。

稍微修改一下getSavedObjectFromPreference()的签名——从Class<GenericClass> classType到Type classType将使这个解决方案一般化。修改后的函数签名

public static <GenericClass> GenericClass getSavedObjectFromPreference(Context context, String preferenceFileName, String preferenceKey, Type classType)

用于调用,

getSavedObjectFromPreference(context, "mPreference", "mObjectKey", (Type) SampleClass.class)

编码快乐!

我的utils类保存列表到SharedPreferences

public class SharedPrefApi {
    private SharedPreferences sharedPreferences;
    private Gson gson;

    public SharedPrefApi(Context context, Gson gson) {
        this.sharedPreferences = context.getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE);
        this.gson = gson;
    } 

    ...

    public <T> void putObject(String key, T value) {
        SharedPreferences.Editor editor = sharedPreferences.edit();
        editor.putString(key, gson.toJson(value));
        editor.apply();
    }

    public <T> T getObject(String key, Class<T> clazz) {
        return gson.fromJson(getString(key, null), clazz);
    }
}

使用

// for save
sharedPrefApi.putList(SharedPrefApi.Key.USER_LIST, userList);

// for retrieve
List<User> userList = sharedPrefApi.getList(SharedPrefApi.Key.USER_LIST, User.class);

. 我的utils的完整代码//检查使用实例的活动代码

// SharedPrefHelper is a class contains the get and save sharedPrefernce data
public class SharedPrefHelper {

    // save data in sharedPrefences
    public static void setSharedOBJECT(Context context, String key, 
                                           Object value) {

        SharedPreferences sharedPreferences =  context.getSharedPreferences(
                context.getPackageName(), Context.MODE_PRIVATE);

        SharedPreferences.Editor prefsEditor = sharedPreferences.edit();
        Gson gson = new Gson();
        String json = gson.toJson(value);
        prefsEditor.putString(key, json);
        prefsEditor.apply();
    }

    // get data from sharedPrefences 
    public static Object getSharedOBJECT(Context context, String key) {

         SharedPreferences sharedPreferences = context.getSharedPreferences(
                           context.getPackageName(), Context.MODE_PRIVATE);

        Gson gson = new Gson();
        String json = sharedPreferences.getString(key, "");
        Object obj = gson.fromJson(json, Object.class);
        User objData = new Gson().fromJson(obj.toString(), User.class);
        return objData;
    }
}
// save data in your activity

User user = new User("Hussein","h@h.com","3107310890983");        
SharedPrefHelper.setSharedOBJECT(this,"your_key",user);        
User data = (User) SharedPrefHelper.getSharedOBJECT(this,"your_key");

Toast.makeText(this,data.getName()+"\n"+data.getEmail()+"\n"+data.getPhone(),Toast.LENGTH_LONG).show();
// User is the class you want to save its objects

public class User {

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getPhone() {
        return phone;
    }

    public void setPhone(String phone) {
        this.phone = phone;
    }

    private String name,email,phone;
    public User(String name,String email,String phone){
          this.name=name;
          this.email=email;
          this.phone=phone;
    }
}
// put this in gradle

compile 'com.google.code.gson:gson:2.7'

希望这对你有所帮助:)