J2ME/Java: Referencing StringBuffer through Threads
- by Jemuel Dalino
This question might be long, but I want to provide much information.
Overview: I'm creating a Stock Quotes Ticker app for Blackberry. But I'm having problems with my StringBuffer that contains an individual Stock information.
Process: My app connects to our server via SocketConnection. The server sends out a formatted set of strings that contains the latest Stock trade. So whenever a new trade happens, the server will send out an individual Stock Quote of that trade. Through an InputStream I am able to read that information and place each character in a StringBuffer that is referenced by Threads. By parsing based on char3 I am able to determine a set of stock quote/information.
char1 - to separate data
char3 - means end of a stock quote/information
sample stock quote format sent out by our server:
stock_quote_name(char 1)some_data(char1)some_data(char1)(char3)
My app then parses that stock quote to compare certain data and formats it how it will look like when displayed in the screen. When trades happen gradually(slow) the app works perfectly. However..
Problem: When trades happen too quickly and almost at the same time, My app is not able to handle the information sent efficiently. The StringBuffer has its contents combined with the next trade. Meaning Two stock information in one StringBuffer.
field should be: Stock_quote_name some_data some_data
sample of what's happening: Stock_quote_name some_data some_dataStock_quote_name some_data some_data
here's my code for this part:
while (-1 != (data = is.read()))
{
sb.append((char)data);
while(3 != (data = is.read()))
{
sb.append((char)data);
}
UiApplication.getUiApplication().invokeLater(new Runnable()
{
public void run()
{
try
{
synchronized(UiApplication.getEventLock())
{
SetStringBuffer(sb);
DisplayStringBuffer();
RefreshStringBuffer();
}
} catch (Exception e)
{
System.out.println("Error in setting stringbuffer: " + e.toString());
}
}
});
}
public synchronized void DisplayStringBuffer()
{
try
{
//parse sb - string buffer
......
}
catch(Exception ex)
{
System.out.println("error in DisplayStringBuffer(): " + ex.toString());
}
}
public synchronized void SetStringBuffer(StringBuffer dataBuffer)
{
this.sb =dataBuffer;
System.out.println(sb);
}
public synchronized void RefreshStringBuffer()
{
this.sb.delete(0, this.sb.length());
}
From what I can see, when trades happen very fast, The StringBuffer is not refreshed immediately and still has the contents of the previous trade, when i try to put new data.
My Question is:
Do you guys have any suggestion on how i can put data into the StringBuffer, without the next information being appended to the first content
