Question

我在我的Android应用程序中使用 Realm 作为数据模块，但我遇到了一些有关如何为Realm对象分配自定义方法的问题。在iOS coredata模块中，您有NSObjects，它们可以保存到内存中，并且允许在各自的类中进行延展性。我可以使用什么样的系统来解决这个问题？我尝试制作＆＃34;父母课程＆＃34;对于我所有的领域对象，但这没有用。

例如：＆＃34; TeacherRealm＆＃34;只会包含教师对象的getter和setter，而＃34; TeacherParent＆＃34;允许用户运行某些算法来查找教师的数据。在TeacherParent类中，我尝试初始化TeacherRealm，在TeacherRealm中，我为TeacherParent对象提供了一个getter和setter。低，请注意，我的TeacherRealm对象类不支持自定义TeacherParent对象。

有没有人遇到过这个问题/找到了解决方案呢？我知道这听起来很混乱，但我可以在必要时提供更多信息

Answer 1

编辑：Realm 0.88.0 has enabled the usage of custom methods，您还可以实现与Realm对象的接口。但我保留了我的存储库模式，这是下面的原始答案。撰写本文时的最新版本为0.88.1。

我坚信data个对象应该只包含数据，逻辑应该是分开的。

public interface RealmRepository<T extends RealmObject, ID extends Serializable> {
    T findOne(Realm realm, ID id);

    RealmResults<T> findAll(Realm realm);

    void insertOrUpdate(Realm realm, T t);

    void insertOrUpdate(Realm realm, Collection<T> t);

    T saveOrUpdate(Realm realm, T t);

    RealmList<T> saveOrUpdate(Realm realm, RealmList<T> tList);

    RealmQuery<T> query(Realm realm);

    void delete(Realm realm, ID id);

    void delete(Realm realm, T t);

    void deleteAll(Realm realm, RealmResults<T> realmResults);

    void deleteEveryObject(Realm realm);

    long count(Realm realm);
}

和

public abstract class BaseRealmRepositoryImpl<T extends RealmObject, ID extends Serializable>
        implements RealmRepository<T, ID> {
    protected Class<T> clazz;

    public BaseRealmRepositoryImpl(Class<T> clazz) {
        this.clazz = clazz;
    }

    @Override
    public RealmResults<T> findAll(Realm realm) {
        return query().findAll();
    }

    @Override
    public void insertOrUpdate(Realm realm, T t) {
        realm.insertOrUpdate(t);
    }

    @Override
    public void insertOrUpdate(Realm realm, Collection<T> collection) {
        realm.insertOrUpdate(collection);
    }

    @Override
    public T saveOrUpdate(Realm realm, T t) {
        return realm.copyToRealmOrUpdate(t);
    }

    @Override
    public RealmList<T> saveOrUpdate(Realm realm, RealmList<T> list) {
        RealmList<T> realmList = new RealmList<>();
        for(T t : realm.copyToRealmOrUpdate(list)) {
            realmList.add(t);
        }
        return realmList;
    }

    @Override
    public RealmQuery<T> query(Realm realm) {
        return realm.where(clazz);
    }

    @Override
    public void deleteEveryObject(Realm realm) {
        realm.delete(clazz);
    }

    @Override
    public void delete(Realm realm, T t) {
        t.deleteFromRealm();
    }

    @Override
    public void deleteAll(Realm realm, RealmResults<T> realmResults) {
        realmResults.deleteAllFromRealm();
    }

    @Override
    public long count(Realm realm) {
        return query().count();
    }
}

和

public abstract class StringRealmRepositoryImpl<T extends RealmObject>
        extends BaseRealmRepositoryImpl<T, String>
        implements RealmRepository<T, String> {
    public StringRealmRepositoryImpl(Class<T> clazz) {
        super(clazz);
    }

    @Override
    public T findOne(Realm realm, String id) {
        return query(realm).equalTo(getIdFieldName(), id).findFirst();
    }

    @Override
    public void delete(Realm realm, String id) {
        delete(realm, findOne(realm, id));
    }
}

和

public class TeacherRealm extends RealmObject {
    @PrimaryKey
    private String id;
    //getter, setter, etc.
}

和

public class TeacherRepositoryImpl
        extends StringRealmRepositoryImpl<TeacherRealm>
        implements TeacherRepository {
    public TeacherRepositoryImpl() {
        super(TeacherRealm.class);
    }
}

存储库是可扩展的。

Answer 2

我有同样的情况在realmObjects中找到解决自定义逻辑的方法。

我以一种舒适的方式滥用了建造者模式。

示例：

public class Information extends RealmObject { @PrimaryKey private String id; private int value; private String text; //getter and setter for id, value and text //Helps to create and commit a information realm object public static class Create { private Realm realm; private Information information; public Create() { this.realm = Realm.getDefaultInstance(); this.realm.beginTransaction(); this.information = realm.createObject(Information.class); //init realmObject with defauls this.information.setId(UUID.randomUUID().toString()); this.information.setValue(0); this.information.setText(""); //space for additional logic } public Create setValue(int val) { this.information.setValue(val); //space for additional logic return this; } public Create setText(String s) { this.information.setText(s); //space for additional logic return this; } public Information commit() { //space for additional logic this.realm.commitTransaction(); return this.information; } } //Helps to modify and commit a information realm object public static class Modify { private Realm realm; private Information information; public Modify(Information information) { this.realm = Realm.getDefaultInstance(); this.information = information; this.realm.beginTransaction(); } public Modify setValue(int val) { this.information.setValue(val); //space for additional logic return this; } public Modify setText(String s) { this.information.setText(s); //space for additional logic return this; } public void commit() { //space for additional logic this.realm.commitTransaction(); } } }

如何使用

//create a reamlobject Information info = new Information.Create() .setText("Hello World"); .commit(); //modify the created info object new Information.Modify(info) .setValue(1) .commit();

RealmObjects中的自定义方法...解决方案？

2 个答案: