ObtainQuoteMIDlet，,//Listing 7.

ObtainQuoteMIDlet，,//Listing 7.

//Listing 7.5import javax.microedition.midlet.*;import javax.microedition.lcdui.*;import javax.microedition.rms.*;public class ObtainQuoteMIDlet extends MIDlet {   private Display displayMngr = null;   private EntryForm entryForm = null;   private Alert resultsAlert = null;   private Ticker adTicker =   new Ticker("Track your investments with Investment Tracker");   public ObtainQuoteMIDlet () {   }   private void initListener () {      ItemStateListener itemListener = new ItemStateListener () {         public void itemStateChanged (Item item) {            if ((item == entryForm.getInvestmentChoice()) && (entryForm.getInvestmentChoice().getSelectedIndex() == 1) && !(entryForm.getSymbolField().getString().toUpperCase().endsWith("X"))) {               Alert symbolAlert = new Alert("Check Symbol","Mutual Funds end in 'X'", null, AlertType.WARNING);               symbolAlert.setTimeout(Alert.FOREVER);               displayMngr.setCurrent(symbolAlert, entryForm);            }         }      };      CommandListener commandListener = new CommandListener() {         public void commandAction(Command c, Displayable d) {            if (c == entryForm.getExitCommand()) {               destroyApp(true);            } else if (c == entryForm.getGetCommand()) {               if ((entryForm.getInvestmentChoice().getSelectedIndex() == 1) && !(entryForm.getSymbolField().getString().toUpperCase().endsWith("X"))){                  Alert symbolAlert = new Alert("Check Symbol","Mutual Funds end in 'X'", null, AlertType.WARNING);                  symbolAlert.setTimeout(Alert.FOREVER);                  displayMngr.setCurrent(symbolAlert, entryForm);               } else if (entryForm.getSymbolField().getString().length() > 0) {                  String sym = entryForm.getSymbolField().getString();                  int type = entryForm.getInvestmentChoice().getSelectedIndex();                  int[] price = QuoteService.getPrice(sym, type);                  if (price != null) {                     storePrice(sym, price);                     displayPrice("The price of " + sym + " is $" + price[0] + "." + price[1]);                  } else {                     Alert symbolAlert = new Alert("Check Symbol/Type", "No quote found.", null, AlertType.WARNING);                     symbolAlert.setTimeout(Alert.FOREVER);                     displayMngr.setCurrent(symbolAlert, entryForm);                  }               }            }         }      };      entryForm.setItemStateListener(itemListener);      entryForm.setCommandListener(commandListener);   }   private void displayEntryForm () {      if (entryForm == null) {         entryForm = new EntryForm("ObtainQuote");      }      initListener();      displayMngr.setCurrent(entryForm);   }   private void displayPrice(String quoteString) {      if (resultsAlert == null) {         resultsAlert = new Alert("Quote Price", null, null,         AlertType.CONFIRMATION);         resultsAlert.setTicker(adTicker);         resultsAlert.setTimeout(Alert.FOREVER);      }      resultsAlert.setString(quoteString);      displayMngr.setCurrent(resultsAlert, entryForm);   }   private void storePrice(String symbol, int[] price) {      String newRecord = symbol + ";" + price[0] + ";" + price[1];      byte[] byteRec;      try {         RecordStore anRMS = RecordStore.openRecordStore("Quotes" , true);         RecordFilter rf = new QuoteFilter(symbol);         RecordEnumeration rEnum = anRMS.enumerateRecords(rf,null,false);         if (rEnum.hasNextElement()) {            int recId = rEnum.nextRecordId();            newRecord += ';' + getLastPrice(anRMS.getRecord(recId));            byteRec = newRecord.getBytes();            anRMS.setRecord(recId,byteRec,0,byteRec.length);         } else {            byteRec = newRecord.getBytes();            anRMS.addRecord(byteRec,0,byteRec.length);         }         rEnum.destroy();         anRMS.closeRecordStore();      } catch (RecordStoreFullException fullStore) {         //handle a full record store problem      } catch (RecordStoreNotFoundException notFoundException) {         //handle store not found which should not happen with the      } catch (RecordStoreException recordStoreException) {         //handling record store problems      }   }   private int[] parsePrices(byte[] quoteRec) {      String rec = new String(quoteRec);      int dollar1Pos = rec.indexOf(';');      int cent1Pos = rec.indexOf(';',dollar1Pos+1);      int dollar2Pos = rec.indexOf(';',cent1Pos + 1);      if (dollar2Pos > 0) { //had a historical price         int cent2Pos = rec.indexOf(';',dollar2Pos + 1);         int currentDollars = Integer.parseInt(rec.substring(dollar1Pos + 1,cent1Pos));         int currentCents = Integer.parseInt(rec.substring(cent1Pos + 1,dollar2Pos));         int historicalDollars = Integer.parseInt(rec.substring(dollar2Pos + 1,cent2Pos));         int historicalCents = Integer.parseInt(rec.substring(cent2Pos + 1));         int[] returnPrices = {currentDollars, currentCents, historicalDollars, historicalCents};         return returnPrices;      } else { //no previous historical price         int currentDollars = Integer.parseInt(rec.substring(dollar1Pos + 1, cent1Pos));         int currentCents = Integer.parseInt(rec.substring(cent1Pos + 1));         int[] returnPrices = {currentDollars, currentCents};         return returnPrices;      }   }   private String getLastPrice(byte[] rec) {      String recString = new String(rec);      int dollarPos = recString.indexOf(';');      int centPos = recString.indexOf(';',dollarPos+1);      int centEnd = recString.indexOf(';',centPos + 1);      if (centEnd > 0) //had a historical price         return recString.substring(dollarPos+1,centEnd);      else //no previous historical price         return recString.substring(dollarPos+1);   }   protected void startApp() {      displayMngr = Display.getDisplay(this);      displayEntryForm();   }   protected void pauseApp() {   }   protected void destroyApp(boolean unconditional) {      notifyDestroyed();   }   public void commandAction(Command c, Displayable s) {   }}//该片段来自于http://byrx.net