package miniforum.data; 
 
import miniforum.data.Message; 
import miniforum.IConstants; 
 
import javax.servlet.ServletContext; 
import java.util.ArrayList; 
 
public class MessageUtils { 
    public static synchronized Message[] getForumMessages( 
            ServletContext aApplication) { 
        ArrayList msgs = (ArrayList) aApplication.getAttribute( 
            IConstants.FORUM_MESSAGES); 
        if (msgs == null) { 
            msgs = new ArrayList(); 
            aApplication.setAttribute( 
                IConstants.FORUM_MESSAGES, msgs); 
        } 
 
        Message[] copyOfMsgs = 
            (Message[]) msgs.toArray(new Message[]{}); 
        return copyOfMsgs; 
    } 
 
    public static synchronized void addForumMessage( 
            ServletContext aApplication, Message aMessage) { 
        if (aMessage.getSubject() == null || 
                aMessage.getSubject().length() == 0 || 
                aMessage.getContents() == null || 
                aMessage.getContents().length() == 0) { 
            throw new IllegalArgumentException("Invalid msg!"); 
        } 
        ArrayList msgs = (ArrayList) aApplication.getAttribute( 
            IConstants.FORUM_MESSAGES); 
        msgs.add(aMessage); 
    } 
 
    public static synchronized void deleteForumMessage( 
            long aID, ServletContext aApplication) { 
        ArrayList msgs = (ArrayList) aApplication.getAttribute( 
            IConstants.FORUM_MESSAGES); 
        for (int i=0; i<msgs.size(); i++) { 
            Message msg = (Message) msgs.get(i); 
            if (msg.getID() == aID) { 
                // Message found. Delete it 
                msgs.remove(i); 
                return; 
            } 
        } 
        throw new IllegalArgumentException("Invalid msg ID!"); 
    } 
}