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

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);

其他回答

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);

看这里,这可以帮助你:

public static boolean setObject(Context context, Object o) {
        Field[] fields = o.getClass().getFields();
        SharedPreferences sp = context.getSharedPreferences(o.getClass()
                .getName(), Context.MODE_PRIVATE);
        Editor editor = sp.edit();
        for (int i = 0; i < fields.length; i++) {
            Class<?> type = fields[i].getType();
            if (isSingle(type)) {
                try {
                    final String name = fields[i].getName();
                    if (type == Character.TYPE || type.equals(String.class)) {
                        Object value = fields[i].get(o);
                        if (null != value)
                            editor.putString(name, value.toString());
                    } else if (type.equals(int.class)
                            || type.equals(Short.class))
                        editor.putInt(name, fields[i].getInt(o));
                    else if (type.equals(double.class))
                        editor.putFloat(name, (float) fields[i].getDouble(o));
                    else if (type.equals(float.class))
                        editor.putFloat(name, fields[i].getFloat(o));
                    else if (type.equals(long.class))
                        editor.putLong(name, fields[i].getLong(o));
                    else if (type.equals(Boolean.class))
                        editor.putBoolean(name, fields[i].getBoolean(o));

                } catch (IllegalAccessException e) {
                    LogUtils.e(TAG, e);
                } catch (IllegalArgumentException e) {
                    LogUtils.e(TAG, e);
                }
            } else {
                // FIXME 是对象则不写入
            }
        }

        return editor.commit();
    }

https://github.com/AltasT/PreferenceVObjectFile/blob/master/PreferenceVObjectFile/src/com/altas/lib/PreferenceUtils.java

// 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:)

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);

将数据存储在SharedPreference中

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