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

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

其他回答

关于这个问题有很多很好的答案,穆罕穆德·阿米尔·阿里和穆哈默德·埃尔-班纳在Kotlin使用通用方法实现了答案。

为了节省

fun storeObjectInSharedPref(dataObject: Any, prefName: String): Boolean{
    val dataObjectInJson = Gson().toJson(dataObject)
    prefsEditor.putString(prefName, dataObjectInJson)
    return prefsEditor.commit()
}

检索

fun <T> retrieveStoredObject(prefName: String, baseClass: Class<T>): T?{
    val dataObject: String? = preferences.getString(prefName, "")
    return Gson().fromJson(dataObject, baseClass)
}

要了解Kotlin中的泛型,请访问这里

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);

// 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:)

试试这个最好的方法:

PreferenceConnector.java

import android.content.Context;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;

public class PreferenceConnector {
    public static final String PREF_NAME = "ENUMERATOR_PREFERENCES";
    public static final String PREF_NAME_REMEMBER = "ENUMERATOR_REMEMBER";
    public static final int MODE = Context.MODE_PRIVATE;


    public static final String name = "name";


    public static void writeBoolean(Context context, String key, boolean value) {
        getEditor(context).putBoolean(key, value).commit();
    }

    public static boolean readBoolean(Context context, String key,
            boolean defValue) {
        return getPreferences(context).getBoolean(key, defValue);
    }

    public static void writeInteger(Context context, String key, int value) {
        getEditor(context).putInt(key, value).commit();

    }

    public static int readInteger(Context context, String key, int defValue) {
        return getPreferences(context).getInt(key, defValue);
    }

    public static void writeString(Context context, String key, String value) {
        getEditor(context).putString(key, value).commit();

    }

    public static String readString(Context context, String key, String defValue) {
        return getPreferences(context).getString(key, defValue);
    }

    public static void writeLong(Context context, String key, long value) {
        getEditor(context).putLong(key, value).commit();
    }

    public static long readLong(Context context, String key, long defValue) {
        return getPreferences(context).getLong(key, defValue);
    }

    public static SharedPreferences getPreferences(Context context) {
        return context.getSharedPreferences(PREF_NAME, MODE);
    }

    public static Editor getEditor(Context context) {
        return getPreferences(context).edit();
    }

}

写入值:

PreferenceConnector.writeString(this, PreferenceConnector.name,"Girish");

并获得价值使用:

String name= PreferenceConnector.readString(this, PreferenceConnector.name, "");

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