listenerrms.java

大量j2me源代码

import java.io.*;
import javax.microedition.midlet.*;
import javax.microedition.rms.*;

/**
 * An example of how to use the MIDP 1.0 Record Management System (RMS)
 * Listener interface.
 * @author Martin J. Wells
 */
public class ListenerRMS extends MIDlet
{
   /**
    * An inner class which implements the RecordListener interface.
    */
   class Listener implements RecordListener
   {
      /**
       * Called when a record is added to a record store.
       * @param recordStore the store it was added to
       * @param i the record index it was assigned
       */
      public void recordAdded(RecordStore recordStore, int i)
      {
         try
         {
            System.out.println("Record " + i + " added to " + recordStore.getName());
         }
         catch(Exception e)
         {
            System.out.println(e);
         }
      }

      /**
       * Called when an existing record was changed.
       * @param recordStore the store where the record resided
       * @param i the index of the record
       */
      public void recordChanged(RecordStore recordStore, int i)
      {
         try
         {
            System.out.println("Record " + i + " changed in " + recordStore.getName());
         }
         catch (Exception e)
         {
            System.out.println(e);
         }
      }

      /**
       * Called when an exsiting record is deleted.
       * @param recordStore the store it was deleted from
       * @param i the index of the record that was deleted
       */
      public void recordDeleted(RecordStore recordStore, int i)
      {
         try
         {
            System.out.println("Record " + i + " deleted from " + recordStore.getName());
         }
         catch (Exception e)
         {
            System.out.println(e);
         }
      }
   }

   private RecordStore rs;
   private static final String STORE_NAME = "My Record Store";

   /**
    * Constructor for the demonstration MIDlet does all the work for the tests.
    * It firstly opens (or creates if required) a record store and then inserts
    * some records containing data. It then reads those records back and
    * displays the results on the console. The associated Listener object will
    * output messages as this process runs.
    * @throws Exception
    */
   public ListenerRMS() throws Exception
   {
      // Open (and optionally create a record store for our data
      rs = RecordStore.openRecordStore(STORE_NAME, true);
      rs.addRecordListener(new Listener());

      // Create some records in the store
      String[] words = {"they", "mostly", "come", "at", "night"};
      for (int i=0; i < words.length; i++)
      {
         // Create a byte stream we can write to
         ByteArrayOutputStream byteOutputStream = new ByteArrayOutputStream();

         // To make life easier use a DataOutputStream to write the bytes
         // to the byteStream (ie. we get the writeXXX methods)
         DataOutputStream dataOutputStream = new DataOutputStream(byteOutputStream);
         dataOutputStream.writeUTF(words[i]);
         // ... add other dataOutputStream.writeXXX statements if you like
         dataOutputStream.flush();

         // add the record
         byte[] recordOut = byteOutputStream.toByteArray();
         int newRecordId = rs.addRecord(recordOut, 0, recordOut.length);
         System.out.println("Adding new record: " + newRecordId +
                            " Value: " + recordOut.toString());

         dataOutputStream.close();
         byteOutputStream.close();
      }

      // retrieve the state of the store now that it's been populated
      System.out.println("Record store now has " + rs.getNumRecords() +
                         " record(s) using " + rs.getSize() + " byte(s) " +
                         "[" + rs.getSizeAvailable() + " bytes free]");

      // retrieve the records
      for (int i=1; i <= rs.getNumRecords(); i++)
      {
         int recordSize = rs.getRecordSize(i);
         if (recordSize > 0)
         {
            // construct a byte and wrapping data stream to read back the
            // java types from the binary format
            ByteArrayInputStream byteInputStream = new ByteArrayInputStream(rs.getRecord(i));
            DataInputStream dataInputStream = new DataInputStream(byteInputStream);

            String value = dataInputStream.readUTF();
            // ... add other dataOutputStream.readXXX statements here matching the
            // order they were written above

            System.out.println("Retrieved record: " + i + " Value: " + value);

            dataInputStream.close();
            byteInputStream.close();
         }
      }


   }

   /**
    * Called by the Application Manager when the MIDlet is starting or resuming
    * after being paused. In this case we just exit as soon as we start.
    * @throws MIDletStateChangeException
    */
   protected void startApp() throws MIDletStateChangeException
   {
      destroyApp(false);
      notifyDestroyed();
   }

   /**
    * Called by the MID's Application Manager to pause the MIDlet. A good
    * example of this is when the user receives an incoming phone call whilst
    * playing your game. When they're done the Application Manager will call
    * startApp to resume. For this example we don't need to do anything.
    */
   protected void pauseApp()
   {
   }

   /**
    * Called by the MID's Application Manager when the MIDlet is about to
    * be destroyed (removed from memory). You should take this as an opportunity
    * to clear up any resources and save the game. For this example we don't
    * need to do anything.
    * @param unconditional if false you have the option of throwing a
    * MIDletStateChangeException to abort the destruction process.
    * @throws MIDletStateChangeException
    */
   protected void destroyApp(boolean unconditional) throws MIDletStateChangeException
   {
   }

}