另一种不使用Json格式保存和恢复android sharedpreferences对象的方法

private static ExampleObject getObject(Context c,String db_name){
            SharedPreferences sharedPreferences = c.getSharedPreferences(db_name, Context.MODE_PRIVATE);
            ExampleObject o = new ExampleObject();
            Field[] fields = o.getClass().getFields();
            try {
                for (Field field : fields) {
                    Class<?> type = field.getType();
                    try {
                        final String name = field.getName();
                        if (type == Character.TYPE || type.equals(String.class)) {
                            field.set(o,sharedPreferences.getString(name, ""));
                        } else if (type.equals(int.class) || type.equals(Short.class))
                            field.setInt(o,sharedPreferences.getInt(name, 0));
                        else if (type.equals(double.class))
                            field.setDouble(o,sharedPreferences.getFloat(name, 0));
                        else if (type.equals(float.class))
                            field.setFloat(o,sharedPreferences.getFloat(name, 0));
                        else if (type.equals(long.class))
                            field.setLong(o,sharedPreferences.getLong(name, 0));
                        else if (type.equals(Boolean.class))
                            field.setBoolean(o,sharedPreferences.getBoolean(name, false));
                        else if (type.equals(UUID.class))
                            field.set(
                                    o,
                                    UUID.fromString(
                                            sharedPreferences.getString(
                                                    name,
                                                    UUID.nameUUIDFromBytes("".getBytes()).toString()
                                            )
                                    )
                            );

                    } catch (IllegalAccessException e) {
                        Log.e(StaticConfig.app_name, "IllegalAccessException", e);
                    } catch (IllegalArgumentException e) {
                        Log.e(StaticConfig.app_name, "IllegalArgumentException", e);
                    }
                }
            } catch (Exception e) {
                System.out.println("Exception: " + e);
            }
            return o;
        }
        private static void setObject(Context context, Object o, String db_name) {
            Field[] fields = o.getClass().getFields();
            SharedPreferences sp = context.getSharedPreferences(db_name, Context.MODE_PRIVATE);
            SharedPreferences.Editor editor = sp.edit();
            for (Field field : fields) {
                Class<?> type = field.getType();
                try {
                    final String name = field.getName();
                    if (type == Character.TYPE || type.equals(String.class)) {
                        Object value = field.get(o);
                        if (value != null)
                            editor.putString(name, value.toString());
                    } else if (type.equals(int.class) || type.equals(Short.class))
                        editor.putInt(name, field.getInt(o));
                    else if (type.equals(double.class))
                        editor.putFloat(name, (float) field.getDouble(o));
                    else if (type.equals(float.class))
                        editor.putFloat(name, field.getFloat(o));
                    else if (type.equals(long.class))
                        editor.putLong(name, field.getLong(o));
                    else if (type.equals(Boolean.class))
                        editor.putBoolean(name, field.getBoolean(o));
                    else if (type.equals(UUID.class))
                        editor.putString(name, field.get(o).toString());

                } catch (IllegalAccessException e) {
                    Log.e(StaticConfig.app_name, "IllegalAccessException", e);
                } catch (IllegalArgumentException e) {
                    Log.e(StaticConfig.app_name, "IllegalArgumentException", e);
                }
            }

            editor.apply();
        }

你还没有说明在这之后你对prefsEditor对象做了什么，但是为了持久化首选项数据，你还需要使用:

prefsEditor.commit();

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);

将数据存储在SharedPreference中

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

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);

我已经使用jackson来存储我的对象(jackson)。

添加杰克逊库到gradle:

api 'com.fasterxml.jackson.core:jackson-core:2.9.4'
api 'com.fasterxml.jackson.core:jackson-annotations:2.9.4'
api 'com.fasterxml.jackson.core:jackson-databind:2.9.4'

我的测试类:

public class Car {
    private String color;
    private String type;
    // standard getters setters
}

Java对象转换为JSON:

ObjectMapper objectMapper = new ObjectMapper();
String carAsString = objectMapper.writeValueAsString(car);

存储在共享首选项中:

preferences.edit().car().put(carAsString).apply();

从共享首选项中恢复:

ObjectMapper objectMapper = new ObjectMapper();
Car car = objectMapper.readValue(preferences.car().get(), Car.class);