你可以保存对象在首选项不使用任何库，首先你的对象类必须实现Serializable:

public class callModel implements Serializable {

private long pointTime;
private boolean callisConnected;

public callModel(boolean callisConnected,  long pointTime) {
    this.callisConnected = callisConnected;
    this.pointTime = pointTime;
}
public boolean isCallisConnected() {
    return callisConnected;
}
public long getPointTime() {
    return pointTime;
}

}

然后你可以很容易地使用这两个方法来转换对象到字符串和字符串到对象:

 public static <T extends Serializable> T stringToObjectS(String string) {
    byte[] bytes = Base64.decode(string, 0);
    T object = null;
    try {
        ObjectInputStream objectInputStream = new ObjectInputStream(new ByteArrayInputStream(bytes));
        object = (T) objectInputStream.readObject();
    } catch (Exception e) {
        e.printStackTrace();
    }
    return object;
}

 public static String objectToString(Parcelable object) {
    String encoded = null;
    try {
        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
        ObjectOutputStream objectOutputStream = new ObjectOutputStream(byteArrayOutputStream);
        objectOutputStream.writeObject(object);
        objectOutputStream.close();
        encoded = new String(Base64.encodeToString(byteArrayOutputStream.toByteArray(), 0));
    } catch (IOException e) {
        e.printStackTrace();
    }
    return encoded;
}

保存:

SharedPreferences  mPrefs = getPreferences(MODE_PRIVATE);
Editor prefsEditor = mPrefs.edit();
prefsEditor.putString("MyObject", objectToString(callModelObject));
prefsEditor.commit();

阅读

String value= mPrefs.getString("MyObject", "");
MyObject obj = stringToObjectS(value);

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;
}

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);

下面是我从这里获得的Kotlin Delegated Properties的使用方法，但扩展了它，并允许使用一种简单的机制来获取/设置SharedPreference属性。

对于String, Int, Long, Float或Boolean，它使用标准的SharePreference getter和setter。然而，对于所有其他数据类，它使用GSON序列化为一个String，用于setter。然后为getter反序列化为数据对象。

与其他解决方案类似，这需要在gradle文件中添加GSON作为依赖项:

implementation 'com.google.code.gson:gson:2.8.6'

下面是一个简单的数据类的例子，我们希望能够保存并存储到SharedPreferences:

data class User(val first: String, val last: String)

下面是一个实现属性委托的类:

object UserPreferenceProperty : PreferenceProperty<User>(
    key = "USER_OBJECT",
    defaultValue = User(first = "Jane", last = "Doe"),
    clazz = User::class.java)

object NullableUserPreferenceProperty : NullablePreferenceProperty<User?, User>(
    key = "NULLABLE_USER_OBJECT",
    defaultValue = null,
    clazz = User::class.java)

object FirstTimeUser : PreferenceProperty<Boolean>(
        key = "FIRST_TIME_USER",
        defaultValue = false,
        clazz = Boolean::class.java
)

sealed class PreferenceProperty<T : Any>(key: String,
                                         defaultValue: T,
                                         clazz: Class<T>) : NullablePreferenceProperty<T, T>(key, defaultValue, clazz)

@Suppress("UNCHECKED_CAST")
sealed class NullablePreferenceProperty<T : Any?, U : Any>(private val key: String,
                                                           private val defaultValue: T,
                                                           private val clazz: Class<U>) : ReadWriteProperty<Any, T> {

    override fun getValue(thisRef: Any, property: KProperty<*>): T = HandstandApplication.appContext().getPreferences()
            .run {
                when {
                    clazz.isAssignableFrom(String::class.java) -> getString(key, defaultValue as String?) as T
                    clazz.isAssignableFrom(Int::class.java) -> getInt(key, defaultValue as Int) as T
                    clazz.isAssignableFrom(Long::class.java) -> getLong(key, defaultValue as Long) as T
                    clazz.isAssignableFrom(Float::class.java) -> getFloat(key, defaultValue as Float) as T
                    clazz.isAssignableFrom(Boolean::class.java) -> getBoolean(key, defaultValue as Boolean) as T
                    else -> getObject(key, defaultValue, clazz)
                }
            }

    override fun setValue(thisRef: Any, property: KProperty<*>, value: T) = HandstandApplication.appContext().getPreferences()
            .edit()
            .apply {
                when {
                    clazz.isAssignableFrom(String::class.java) -> putString(key, value as String?) as T
                    clazz.isAssignableFrom(Int::class.java) -> putInt(key, value as Int) as T
                    clazz.isAssignableFrom(Long::class.java) -> putLong(key, value as Long) as T
                    clazz.isAssignableFrom(Float::class.java) -> putFloat(key, value as Float) as T
                    clazz.isAssignableFrom(Boolean::class.java) -> putBoolean(key, value as Boolean) as T
                    else -> putObject(key, value)
                }
            }
            .apply()

    private fun Context.getPreferences(): SharedPreferences = getSharedPreferences(APP_PREF_NAME, Context.MODE_PRIVATE)

    private fun <T, U> SharedPreferences.getObject(key: String, defValue: T, clazz: Class<U>): T =
            Gson().fromJson(getString(key, null), clazz) as T ?: defValue

    private fun <T> SharedPreferences.Editor.putObject(key: String, value: T) = putString(key, Gson().toJson(value))

    companion object {
        private const val APP_PREF_NAME = "APP_PREF"
    }
}

注意:您不需要更新密封类中的任何内容。委托的属性是对象/单例的UserPreferenceProperty, NullableUserPreferenceProperty和FirstTimeUser。

为了从SharedPreferences中保存/获取一个新的数据对象，现在只需要添加四行就可以了:

object NewPreferenceProperty : PreferenceProperty<String>(
        key = "NEW_PROPERTY",
        defaultValue = "",
        clazz = String::class.java)

最后，你可以通过使用by关键字来读取/写入SharedPreferences的值:

private var user: User by UserPreferenceProperty
private var nullableUser: User? by NullableUserPreferenceProperty
private var isFirstTimeUser: Boolean by 

Log.d("TAG", user) // outputs the `defaultValue` for User the first time
user = User(first = "John", last = "Doe") // saves this User to the Shared Preferences
Log.d("TAG", user) // outputs the newly retrieved User (John Doe) from Shared Preferences

我在使用已接受的答案访问跨活动的共享首选项数据时遇到了麻烦。在这些步骤中，您将为getSharedPreferences提供一个名称以访问它。

在构建中添加以下依赖项。Gradle脚本下的gradel (Module: app)文件:

implementation 'com.google.code.gson:gson:2.8.5'

保存:

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

SharedPreferences mPrefs = getSharedPreferences("Name", Context.MODE_PRIVATE);

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

在不同的活动中检索:

SharedPreferences mPrefs = getSharedPreferences("Name", Context.MODE_PRIVATE);

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

步骤1:在java文件中复制粘贴这两个函数。

 public void setDefaults(String key, String value, Context context) {
        SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(context);
        SharedPreferences.Editor editor = preferences.edit();
        editor.putString(key, value);
        editor.commit();
    }


    public static String getDefaults(String key, Context context) {
        SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(context);
        return preferences.getString(key, null);
    }

步骤2: 为了节省使用:

 setDefaults("key","value",this);

检索使用:

String retrieve= getDefaults("key",this);

你可以通过使用不同的键名来设置不同的共享首选项，比如:

setDefaults("key1","xyz",this);

setDefaults("key2","abc",this);

setDefaults("key3","pqr",this);