serialization

问题 Looking for some fast, simple and stable RPC library I stumbled upon MessagePack project which seems to be very good. It is also under active development. If you used it in any way, could you please share your experience? P.S. I think this question should be community wiki 回答1: Well, after some time I found that MessagePack is not well-documented (there was even non-working tutorial in Wiki for Java), there are like 7 outstanding bugs several months old without any replies. Code even is not

问题 Looking for some fast, simple and stable RPC library I stumbled upon MessagePack project which seems to be very good. It is also under active development. If you used it in any way, could you please share your experience? P.S. I think this question should be community wiki 回答1: Well, after some time I found that MessagePack is not well-documented (there was even non-working tutorial in Wiki for Java), there are like 7 outstanding bugs several months old without any replies. Code even is not

问题 I am reading the serialization chapter in "Effective Java". I am trying to understand the below paragraph in the book. If you implement a class with instance fields that is serializable and extendable,there is a caution you should be aware of. If the class has invariants that would be violated if its instance fields were initialized to their default values (zero for integral types, false for boolean, and null for object reference types), you must add this readObjectNoData method to the class:

问题 Is it possible to get the current user in a model serializer? I'd like to do so without having to branch away from generics, as it's an otherwise simple task that must be done. My model: class Activity(models.Model): number = models.PositiveIntegerField( blank=True, null=True, help_text="Activity number. For record keeping only.") instructions = models.TextField() difficulty = models.ForeignKey(Difficulty) categories = models.ManyToManyField(Category) boosters = models.ManyToManyField(Booster

问题 Is it possible to get the current user in a model serializer? I'd like to do so without having to branch away from generics, as it's an otherwise simple task that must be done. My model: class Activity(models.Model): number = models.PositiveIntegerField( blank=True, null=True, help_text="Activity number. For record keeping only.") instructions = models.TextField() difficulty = models.ForeignKey(Difficulty) categories = models.ManyToManyField(Category) boosters = models.ManyToManyField(Booster

问题 Is there a simple, hassle-free approach to serialization in Scala/Java that's similar to Python's pickle? Pickle is a dead-simple solution that's reasonably efficient in space and time (i.e. not abysmal) but doesn't care about cross-language accessibility, versioning, etc. and allows for optional customization. What I'm aware of: Java's built-in serialization is infamously slow ([1], [2]), bloated, and fragile. Also have to mark classes as Serializable---annoying when there are things that

问题 Why does my custom Exception class below not serialize/unserialize correctly using the pickle module? import pickle class MyException(Exception): def __init__(self, arg1, arg2): self.arg1 = arg1 self.arg2 = arg2 super(MyException, self).__init__(arg1) e = MyException("foo", "bar") str = pickle.dumps(e) obj = pickle.loads(str) This code throws the following error: Traceback (most recent call last): File "test.py", line 13, in <module> obj = pickle.loads(str) File "/usr/lib/python2.7/pickle.py"

问题 What i'm trying to do is to send and ArrayList through a socket from Android client to Java server. Here is the code of client which sends the ArrayList : private void sendContacts(){ AppHelper helperClass = new AppHelper(getApplicationContext()); final ArrayList<Person> list = helperClass.getContacts(); System.out.println("Lenght of an contacts array : " +list.size()); // for (Person person : list) { // System.out.println("Name "+person.getName()+"\nNumber "+ person.getNr()); // } handler

问题 I have a HashMap < String,ArrayList < Integer > >. I want to serialize my HashMap object(hmap) to HDFS location and later deserialize it at Mapper and Reducers for using it. To serialize my HashMap object on HDFS I used normal java object serialization code as follows but got error (permission denied) try { FileOutputStream fileOut =new FileOutputStream("hashmap.ser"); ObjectOutputStream out = new ObjectOutputStream(fileOut); out.writeObject(hm); out.close(); } catch(Exception e) { e

问题 struct MemoryTag1; typedef struct MemoryTag1{ char a[8]= {'+','0','2','6','.','5','EA','\r'}; // setpoint temperature value char b[8]= {'-','0','2','4','.','5','EB','\r'}; char c[6]= {'+','0','2','0','EC','\r'}; }Memory1; // This is a message structure which I want to transfer over the serial interface (RS232) and later convert into integer value. please guide me in this. 回答1: Your syntax is a bit off - try this: // declare Memory1 struct type to hold data typedef struct MemoryTag1 { char a[9