ORMLite 5和翻新2的递归对象序列化问题

Question

我有2个类似以下代码示例的类：

A级

@DatabaseField(id = true, columnName = "id")
private UUID id;
@ForeignCollectionField
private LazyForeignCollection<B, UUID> bList;

B级

@DatabaseField(id = true)
private UUID id;
@DatabaseField(columnName = "idA", foreign = true)
private A objA;
@DatabaseField
private String foo;

我遇到了使用Retrofit2将数据从android发送到API的问题，因为当我发送A时，序列化程序会调用bList，而ORMLite会自动加载它。

我的bList中B的每个对象都填充了“ objA”，每个“ objA”都有一个包含数据的bList。 对应用程序来说还可以，因为它总是分配相同的对象，但是GSon序列化程序会尝试序列化每个级别并引发此异常：

ERR: stack=java.lang.RuntimeException: An error occured while executing doInBackground()
                                                               at android.os.AsyncTask$3.done(AsyncTask.java:304)
                                                               at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355)
                                                               at java.util.concurrent.FutureTask.setException(FutureTask.java:222)
                                                               at java.util.concurrent.FutureTask.run(FutureTask.java:242)
                                                               at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
                                                               at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
                                                               at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
                                                               at java.lang.Thread.run(Thread.java:818)
                                                            Caused by: android.database.CursorWindowAllocationException: Cursor window allocation of 2048 kb failed. # Open Cursors=760 (# cursors opened by this proc=760)
                                                               at android.database.CursorWindow.<init>(CursorWindow.java:108)
                                                               at android.database.AbstractWindowedCursor.clearOrCreateWindow(AbstractWindowedCursor.java:198)
                                                               at android.database.sqlite.SQLiteCursor.fillWindow(SQLiteCursor.java:139)
                                                               at android.database.sqlite.SQLiteCursor.getCount(SQLiteCursor.java:133)
                                                               at android.database.AbstractCursor.moveToPosition(AbstractCursor.java:197)
                                                               at android.database.AbstractCursor.moveToFirst(AbstractCursor.java:237)
                                                               at com.j256.ormlite.android.AndroidDatabaseResults.first(AndroidDatabaseResults.java:68)
                                                               at com.j256.ormlite.android.AndroidDatabaseConnection.queryForOne(AndroidDatabaseConnection.java:206)
                                                               at com.j256.ormlite.stmt.mapped.MappedQueryForFieldEq.execute(MappedQueryForFieldEq.java:38)
                                                               at com.j256.ormlite.field.FieldType.createForeignObject(FieldType.java:1047)
                                                               at com.j256.ormlite.field.FieldType.assignField(FieldType.java:556)
                                                               at com.j256.ormlite.stmt.mapped.BaseMappedQuery.mapRow(BaseMappedQuery.java:72)
                                                               at com.j256.ormlite.stmt.SelectIterator.getCurrent(SelectIterator.java:284)
                                                               at com.j256.ormlite.stmt.SelectIterator.nextThrow(SelectIterator.java:168)
                                                               at com.j256.ormlite.stmt.SelectIterator.next(SelectIterator.java:181)
                                                               at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.write(CollectionTypeAdapterFactory.java:96)
                                                               at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.write(CollectionTypeAdapterFactory.java:61)
                                                               at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:68)
                                                               at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.write(ReflectiveTypeAdapterFactory.java:112)
                                                               at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.write(ReflectiveTypeAdapterFactory.java:239)
                                                               at com.google.gson.Gson$FutureTypeAdapter.write(Gson.java:968)
                                                               at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:68)
                                                               at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.write(ReflectiveTypeAdapterFactory.java:112)
                                                               at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.write(ReflectiveTypeAdapterFactory.java:239)
                                                               at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:68)
                                                               at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.write(CollectionTypeAdapterFactory.java:97)
                                                               at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.write(CollectionTypeAdapterFactory.java:61)
                                                               at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:68)
                                                               at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.write(ReflectiveTypeAdapterFactory.java:112)
                                                               at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.write(ReflectiveTypeAdapterFactory.java:239)
                                                               at com.google.gson.Gson$FutureTypeAdapter.write(Gson.java:968)
                                                               at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:68)
                                                               at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.write(ReflectiveTypeAdapterFactory.java:112)
                                                               at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.write(ReflectiveTypeAdapterFactory.java:239)
                                                            at com.google.gson.internal.bind.TypeAdapterRuntime

和这个：

09-11 09:59:16.618 28706-28747/br.com.igtech.nr18 D/Error: ERR: TOTAL BYTES WRITTEN: 1636884
09-11 09:59:16.618 28706-28747/br.com.igtech.nr18 E/JavaBinder: !!! FAILED BINDER TRANSACTION !!!
09-11 09:59:16.628 28706-28747/br.com.igtech.nr18 E/AndroidRuntime: Error reporting crash
                                                                    android.os.TransactionTooLargeException
                                                                        at android.os.BinderProxy.transactNative(Native Method)
                                                                        at android.os.BinderProxy.transact(Binder.java:496)
                                                                        at android.app.ActivityManagerProxy.handleApplicationCrash(ActivityManagerNative.java:4164)
                                                                        at com.android.internal.os.RuntimeInit$UncaughtHandler.uncaughtException(RuntimeInit.java:89)
                                                                        at java.lang.ThreadGroup.uncaughtException(ThreadGroup.java:693)
                                                                        at java.lang.ThreadGroup.uncaughtException(ThreadGroup.java:690)

手动将对象设置为null可以解决此问题，但是我认为这不是最好的方法。

Answer 1

阅读这个和这个

解决了将ConverterFactory从Gson更改为Jackson的问题

retrofit = new Retrofit
                .Builder()
                .baseUrl(baseUrl)
                .addConverterFactory(JacksonConverterFactory.create())
                .client(okHttpClient)
                .build();

Jackson具有@JsonManagedReference和@JsonBackReference批注，可以解决循环问题。