Question

迁移工作非常繁琐，但我的应用程序在某些时候必须重新启动（recreate()）才能进行界面操作。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

迁移代码段：

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

听起来好像是多次创建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因为您的RealmMigration类不会覆盖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

迁移在recreate（）方法之后崩溃

1 个答案: