Simple Serialization Problem

I'm creating a server/client text based game where a user is sent text and serialized information from their personal character class. However, I don't know what type of Reader/Writer I should use to accept both serialized byte code and strings. Is there a way I can use BufferedReader for strings and temporarily pause the input stream to send it a serialized class using ObjectInputStream?
--dorky
Edited by: dorkydude666 on Mar 25, 2009 8:39 AM

As far as I know, there is no write String method for ObjectOutputStream. There's writeChars and writeObject. writeChars changes "Hello" to "H e l l o" and writeObject would be annoying to use when sending plain integers. However, I have got a small prototype working where I just cast the object to String and parseInt for the value. Now I'm getting problems sending my serializable objects over the socket. It sends and receives without error, but it's only sending the first instance of the class. It's confusing, so here's my debugging output:
Server:
user:1 name:dorkydude hp:100
user:1 name:dorkydude hp:80
Client:
user:1 name:dorkydude hp:100
user:1 name:dorkydude hp:100
The server is updating the class, but not sending the updated version. The updated class is sent as the last line of code in my program so it's not a matter of sending it too early. :\
--dorky

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Modify mypanel1's constructor:
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Serialization problem with FlashPlayer 10.1

Hi,
here is a message that I have post in the AS3 section (http://forums.adobe.com/message/2938096), but someone gave the hint that this section should be more appropriate.
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Hi,
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Very strange serialization problem(in what should be a simple solution)

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argg. this seems like it should be such a simple problem but it just won't work. And its almost exactly the same as what I did before...

Yeah, my fault for leaving the catch statements empty.
Anyway, it is the output stream IO that is throwing the exception
What do you mean by: You're probably hiding an instance variable with a member variable, but it's impossible to tell from the little bit of code you've shown.
I can print out more code just need to know what stuff to post.
Here is what i get from the printstacktrace:
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Simple Serializable demo with problems

Hello!
I am having a very simple demo where I tried to see how the Serializable interface works. However, I am receiving message NotSerializableException. What's wrong?
Thanks in advance!
Kind regards,
Igor
Here's the demo:
import java.io.*;
public class SerializationDemo {
private class Data implements Serializable {
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Consider the following code. What do you expect Child.foo() to print? Why? Supposing you made it serializable, how would you expect it to behave when deserialized?
public class Illustration {
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   private Child c;
   private int x;
   private class Child {
      public Child() {
      public void foo() {
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}In case that's not clear, here's a quick illustration:
public class Illustration {
   public class Child { ... }
+--------------+
| Illustration |
|              |
| +-----+     |
| |Child|     |
| +-----+     |
|              |
+--------------+
public class Illustration {
   public static class Child { ... }
+--------------+
| Illustration |    +-----+
|              |--->|Child|
|              |    +-----+
|              |
|              |
|              |
+--------------+Because Child is not declared static, it has full access to all of the fields of Illustration. Therefore if you serialize it in order to work after deserialization as it did before, it must have copies of all of the owning class's fields.
When you declare it static you break this relationship and it becomes independent.
So taking your following question:
Why is this so? Does this mean that the following two statements would produce completely identical results, providing that SerializationDemo class was made Serializable:
oos.writeObject(new Data());
oos.writeObject(this);No, not quite - the first form creates a new Data object, serializes that, then (of necessity) serializes the owning class as well.
The second form just serializes the current class - since it doesn't have an associated Data object, nothing else gets serialized.
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Dave.

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display(xml);
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<something>
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</something>
atr1 is attribute, which is inherited from db table.
atr2 is atribute, which I created (it is not inherited from db table)
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Like I can't serialize attributes, which are inherited from db table.
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Edited by: user12189610 on Nov 9, 2009 2:42 AM
Edited by: user12189610 on Nov 9, 2009 2:46 AM

If you need a simple project that duplicates this problem for customer support, here's where I put one: http://www.4shared.com/file/181611971/d21e9444/_2__DynamicXMLBug.html.
Have them import the project, start Studio's Engine, login as "test" and start the Workspace. Create a work item instance and then run the work item when it reaches the "Test" activity. When you run the logic, you'll see this displayed:
<?xml version="1.0" encoding="UTF-8"?>
<poHeir xmlns="http://bea.com/albpm/DynamicXml/version/2.0">
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Hi there,
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When in this isolation level and a transaction tries to update or delete data modified by a transaction that commits after the serializable transaction began, I get this error:
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EXCEPTION
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end;
END nm_test;
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When I replace the "rollback to savepoint" by just "rollback", everything works fine (the exception is then caught only once) and the update succeeds on the second try.
But I can not work with just a "rollback" because my stored procedures might be called by others for which I don't want to undo all the work.
Do any of you know why I keep getting this error (the program ends up in an infinite loop if I didn't keep a counter and exit after 10 times)?
Marcel van Vuure

Marcel,
First of all, I'd be interested in hearing why you think you need serializable transactions (why 'read committed' doesn't work for your application). In the 8 years I've been building Oracle apps, I've never deemed it necessary to use serializable transactions. Maybe an optimistic locking strategy will solve your problem.
Secondly, if I were designing the interface, I wouldn't have a procedure in charge of both executing business logic AND retrying the logic in case of failure. I'd build a helper procedure that calls the procedure that does the work, looks for certain exceptions, and retries the procedure when necessary.
Lastly, if your interface doesn't have transactional control (the caller is in charge of commits and rollbacks), maybe you should simply attempt the update statement and throw an exception to the caller and let them handle it.
I'm sorry if I haven't directly solved your problem, but sometimes the best way to solve a problem is to question the decisions that got you there in the first place.
Hi there,
I have a problem with my stored procedures when the isolation level of the connection is serializable. I need to set this isolation level because of data consistency reasons.
When in this isolation level and a transaction tries to update or delete data modified by a transaction that commits after the serializable transaction began, I get this error:
ORA-08177: Cannot serialize access for this transaction
This is normal. The thing to do in this case is catch the error in the exception handler, rollback to a certain savepoint and try to do the update again.
The stored procedure that I use to test this is:
CREATE OR REPLACE PROCEDURE nm_test IS
tmpVar NUMBER;
err_num NUMBER;
err_msg VARCHAR2(200);
teller number;
BEGIN
teller := 0;
savepoint sp1;
<<try_every_thing_again>>
begin
tmpVar := 0;
update stock_prices set price = price + 1
where ric = 1;
DBMS_OUTPUT.Put_Line('teller = ' || teller);
EXCEPTION
WHEN others THEN
err_num := SQLCODE;
--err_msg := SUBSTR(SQLERRM, 1, 200);
     if (err_num = -8177) then
          rollback to savepoint sp1;
          --DBMS_LOCK.SLEEP(1);
          teller := teller + 1;
          if (teller < 10) then
               goto try_every_thing_again;
          end if;
          DBMS_OUTPUT.Put_Line('exception: teller = ' || teller);
     end if;
end;
END nm_test;
I test this using 2 connections to the database. In the first connection I run the stored proc (without committing). Then I run the same stored proc in the second connection. This will block on the update (the is an implicit lock), which is ok. Then I commit the first connection. The second catches the error, rolls back and tries the update again....but then it catches the exception again, and again???
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But I can not work with just a "rollback" because my stored procedures might be called by others for which I don't want to undo all the work.
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Instead of LPCTSTR I've also tried the more conventional "char *WinName",
and a few others. All give the same error; "The exception Priviledged
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I'm calling the function using a "Call Library Node", passing a
pre-generated string in the form of a C string pointer. The calling
convention is set to "winapi" but doesn't seem too relevant.
If I remove the string argument and change the function definition to take
(void) then it works, in that I can put integers in the return code and pass
them back to Labview, so it's the passing of the string that's the problem.
However, if I have more code in there and I use the Visual C++ debugger, the
error message is only generated on hitting the "return" line, and I can see
the string that has been passed in when I look at "WinName" in the debugger.
Can anyone shed some light on this?
Craig Graham
Physicist/Labview Programmer
Lancaster University, UK

Craig;
I am going to throw some random thoughts that may help you in your situation:
- I avoid to use VC's wizard. It gives (and gave me) a lot of headaches. All it does it to add a lot of garbage to your project that nobody understand.
- If your source file is a .cpp, wrap your function prototypes inside the extern "C" declaration.
- Always initialize every variable in LabVIEW side. For example, for your function you should wire an empty string in the input side of the "Call Library Node" for the "WinName" variable.
- I claim ignorance in this one, but seems to simplify my projects. Exclude rarely-used Windows header files by adding the following statement before your headers "include":
#define VC_EXTRALEAN
I hope this can be of help. If I co
me up with some more suggestion, I'll let you know.
Best regards;
Enrique
www.vartortech.com

Simple Serialization Problem

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