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

更好的方法是创建一个全局Constants类来保存键或变量以获取或保存数据。

要保存数据,请调用此方法保存来自任何地方的数据。

public static void saveData(Context con, String variable, String data)
{
    SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(con);
    prefs.edit().putString(variable, data).commit();
}

用它来获取数据。

public static String getData(Context con, String variable, String defaultValue)
{
    SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(con);
    String data = prefs.getString(variable, defaultValue);
    return data;
}

像这样的方法就可以了

public static User getUserInfo(Context con)
{
    String id =  getData(con, Constants.USER_ID, null);
    String name =  getData(con, Constants.USER_NAME, null);
    if(id != null && name != null)
    {
            User user = new User(); //Hope you will have a user Object.
            user.setId(id);
            user.setName(name);
            //Here set other credentials.
            return user;
    }
    else
    return null;
}

其他回答

// 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:)

您可以使用以下代码存储类对象,并从共享首选项检索任何对象。

将以下依赖项添加到应用gradle中

dependencies {
 implementation 'com.google.code.gson:gson:2.8.6'
 //Other dependencies of our project
} 

在共享pref文件中添加以下代码。

 /**
 * Saves object into the Preferences.
 *
 * @param `object` Object of model class (of type [T]) to save
 * @param key Key with which Shared preferences to
 **/
fun <T> put(`object`: T, key: String) {
    //Convert object to JSON String.
    val jsonString = GsonBuilder().create().toJson(`object`)
    //Save that String in SharedPreferences
    preferences.edit().putString(key, jsonString).apply()
}

/**
 * Used to retrieve object from the Preferences.
 *
 * @param key Shared Preference key with which object was saved.
 **/
inline fun <reified T> get(key: String): T? {
    //We read JSON String which was saved.
    val value = preferences.getString(key, null)
    //JSON String was found which means object can be read.
    //We convert this JSON String to model object. Parameter "c" (of
    //type Class < T >" is used to cast.
    return GsonBuilder().create().fromJson(value, T::class.java)
}
}

在SharedPreferences中存储Model的数组列表

Add this dependency implementation 'com.google.code.gson:gson:2.8.8' Then after you convert your Model Class into JSON using Gson. Gson gson = new Gson(); String json = gson.toJson(chModelArrayList); //here chModelArrayList is a ArrayList<Model> of Model Class Then after you can add this string to SharedPreferences SharedPreferences preferences; //Create Object of SharedPreferences SharedPreferences.Editor editor; //Create Object of SharedPreferences.Editor //initialize SharedPreferences preferences = activity.getPreferences(Context.MODE_PRIVATE); editor = preferences.edit(); //Add-In SharedPreferences editor.putString(key, json); editor.commit(); for your list from SharedPreferences String json = preferences.getString(key, defVal); Gson gson = new Gson(); //Pass Your Model ArrayList in TypeToken Type type = new TypeToken<ArrayList<ChModel>>() {}.getType(); //here you get your list ArrayList<ChModel> switchGroup1 = gson.fromJson(json, type);

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!

您可以使用gson.jar将类对象存储到SharedPreferences中。 你可以从google-gson下载这个罐子

或者在Gradle文件中添加GSON依赖项:

implementation 'com.google.code.gson:gson:2.8.8'

你可以在这里找到最新的版本

创建共享首选项:

SharedPreferences  mPrefs = getPreferences(MODE_PRIVATE);

保存:

MyObject myObject = new MyObject;
//set variables of 'myObject', etc.

Editor prefsEditor = mPrefs.edit();
Gson gson = new Gson();
String json = gson.toJson(myObject);
prefsEditor.putString("MyObject", json);
prefsEditor.commit();

检索:

Gson gson = new Gson();
String json = mPrefs.getString("MyObject", "");
MyObject obj = gson.fromJson(json, MyObject.class);