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serializable

Serialization Exception on spark

Question I meet a very strange problem on Spark about serialization. The code is as below: class PLSA(val sc : SparkContext, val numOfTopics : Int) extends Serializable { def infer(document: RDD[Document]): RDD[DocumentParameter] = { val docs = documents.map(doc => DocumentParameter(doc, numOfTopics)) docs } } where Document is defined as: class Document(val tokens: SparseVector[Int]) extends Serializable and DocumentParameter is: class DocumentParameter(val document: Document, val theta: Array[Float]) extends Serializable object DocumentParameter extends Serializable { def apply(document

2021-06-21 09:31:02    分类:技术分享    scala   apache-spark   serializable

Can I send custom objects to Android Wear?

Question I am just learning how to develop for Android Wear, I have created a full screen Activity for Smart Watches and in my mobile part of the application I get some JSON data and create a list of custom objects from this. On my mobile app I show the information for these objects in a ListView. On the Wear piece of my application I want to show a limited version of this list, for example the top 3 from the list will be show on my full screen app on the Wearable. My problem is that there doesn't seem to be a way to send Parcelable Objects to Android Wear, there is no option to putParcelable

2021-06-12 14:05:08    分类:技术分享    android   parcelable   serializable   wear-os   android-wear-data-api

Pass serializable object throught intent

Question This is my first attempt to ask for a solution to a problem of mine so try to be kind guys! I have found numerous solutions to problems I deal with in this site by doing simple search but this time I had no luck I guess. I found nothing to fit my problem so I ended asking a new question. I 'm trying to pass an object through an intent from one activity to another. I have one abstract class and two subclasses (the one of them also abstract) as follows. I need them to be abstract. I removed a lot of code (abstract methods etc.) just to find what the problem is and I ended up with these

2021-06-10 21:06:32    分类:技术分享    android   android-intent   serializable

What is the difference between “conflict serializable” and “conflict equivalent”?

Question In database theory, what is the difference between "conflict serializable" and "conflict equivalent"? My textbook has a section on conflict serializable but glosses over conflict equivalence. These are probably both concepts I am familiar with, but I am not familiar with the terminology, so I am looking for an explanation. Answer1 Just two terms to describe one thing in different ways. Conflict equivalent: you need to say Schedule A is conflict equivalent to Schedule B. it must involve two schedules Conflict serializable: Still use Schedule A and B. we can say Schedule A is conflict

2021-06-09 09:47:35    分类:技术分享    database   conflict   serializable   equivalence

Usage of parceler (@Parcel) with Realm.io (Android)

Question I have the following code which produces the error: Error:Parceler: Unable to find read/write generator for type io.realm.Realm for io.realm.RealmObject.realm It was working all fine without extends RealmObject , however I want to use Realm to put to database easily. Is there a way to exlcude the RealmObject fields and just use the basic pojo fields for @Parcel? @Parcel public class Feed extends RealmObject{ int id; public String text; public String time_created; String time_modified; int comments_count; int likes_count; String feed_type; int obj_id; String image; String user_name

2021-06-01 02:34:35    分类:技术分享    android   parcelable   serializable   realm   parceler

de/serialize java objects across different applications using different package names

Question I want to share java objects across different applications. As long as I use the same package names in the different projects it works fine. But if I change the package names it doesn't work anymore. I tried to solve this by extend the ObjectInputStream class and overriding the readClassDescriptor method. But by doing so I get the following error: java.io.StreamCorruptedException: invalid type code: 00 ... dont know how to solve this problem. Here is the code I use for the extended ObjectInputStream class: public class MyObjectInputStream extends ObjectInputStream { public static Map

2021-05-31 19:40:43    分类:技术分享    java   serializable

Socket program to send and receive user defined objects not working

Question I have a user defined class Message, whose object I would like to pass between the client and the server. The Message class is as follows: import java.io.Serializable; public class Message implements Serializable { String CorS; int data_id; int status_id; Integer value; boolean withdraw; public Message() { CorS = null; data_id = 0; status_id = 0; value = 0; withdraw = false; } public Message(String CorS, int data_id, int status_id, Integer value) { this.CorS = CorS; this.data_id = data_id; this.status_id = status_id; this.value = value; } public Message(boolean withdraw) { this

2021-05-24 13:43:09    分类:技术分享    java   sockets   object   serializable

Serializable and transient

Question To make a class serializable we do the following: class A implements Serializable { transient Object a; } And not this: serializable class A { transient Object a; } Why, if we want to make a class serializable, do we implement a special interface. And if we want to exclude some fields we use the keyword transient? Why aren't special keywords used in both cases? I mean were there any reasons to make the same thing in different ways? I know, there is no such keyword as serializable but why wasn't it introduced instead of the special interface Serializable? Answer1 Why isn't used some

2021-05-21 15:58:14    分类:技术分享    java   serializable

How to stop ProGuard from stripping the Serializable interface from a class

Question Is there an explicit way to stop ProGuard from changing a class from implementing an interface? I have a class that implements java.io.Serializable, let's call it com.my.package.name.Foo. I've found that after running through ProGuard, it no longer implements Serializable. I get null after I cast from Serializable to Foo and false if I check an instance with instanceof Serializable. I've made sure to set ProGuard to ignore this class: -keep class com.my.package.name.Foo I've also tried: -keep class com.my.package.name.Foo { *; } and I've also tried the whole package by doing this:

2021-05-18 10:02:51    分类:技术分享    java   android   proguard   serializable

Is there any way to disable ORMLite's check that a field declared with DataType.SERIALIZABLE implements Serializable?

Question Question title just about says it all. I have a field declared like this: @DatabaseField(canBeNull=false,dataType=DataType.SERIALIZABLE) List<ScheduleTriggerPredicate> predicates = Collections.emptyList(); Depending on context, predicates can either contain the empty list or an immutable list returned by Collections.unmodifiableList(List) with an ArrayList as its parameter. I therefore know that the object in question is serializable, but there is no way I can tell the compiler (and therefore ORMLite) that it is. Therefore I get this exception: SEVERE: Servlet /ADHDWeb threw load()

2021-05-18 08:12:20    分类:技术分享    collections   ormlite   serializable