java - recreate() 方法后迁移崩溃

Question

迁移工作正常，但我的应用程序有时必须重新启动(recreate())才能执行界面操作。此时应用程序因迁移而崩溃:

java.lang.RuntimeException: Unable to start activity ComponentInfo{APP/APP.MainActivity}: java.lang.IllegalArgumentException: Configurations cannot be different if used to open the same file. 
                                             Cached configuration: 
                                             realmFolder: /data/user/0/APP/files
                                             realmFileName : default.realm
                                             canonicalPath: /data/data/APP/files/default.realm
                                             key: [length: 0]
                                             schemaVersion: 0
                                             migration: null
                                             deleteRealmIfMigrationNeeded: false
                                             durability: FULL
                                             schemaMediator: io.realm.DefaultRealmModuleMediator@19c237a3

迁移 fragment :

mRealmConfig = new RealmConfiguration.Builder(this)
        .schemaVersion(0)
        .migration(new Migration())
        .build();
realm = Realm.getInstance(mRealmConfig);
realm.close();

迁移类:

public class Migration implements RealmMigration {
@Override
public void migrate(final DynamicRealm realm, long oldVersion, long newVersion) {
    RealmSchema schema = realm.getSchema();

    // Migrate from version 0 to version 1
    if (oldVersion == 0) {
        RealmObjectSchema notificationSchema = schema.get("classTarget");

        notificationSchema
                .addField("something", Boolean.class, FieldAttribute.REQUIRED)
                .transform(new RealmObjectSchema.Function() {
                    @Override
                    public void apply(DynamicRealmObject obj) {
                        obj.set("something", true);
                    }
                });
        oldVersion++;
    }
}
}

Answer 1

听起来您正在多次创建 RealmConfiguration 实例。尝试将其保留在静态字段中或使用 Realm.setDefaultInstance(config)/Realm.getDefaultInstance() 代替。

您看到异常的原因是您的 RealmMigration 类没有重写 equals()/hashCode()。这意味着我们的内部检查认为您有两种不同的配置，因为 new Migration().equals(new Migration()) == false