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RMSGameScores.javaAPI DocJ2ME MIDP 2.07829Thu Nov 07 12:02:16 GMT 2002example

RMSGameScores

public class RMSGameScores extends MIDlet implements RecordFilter, RecordComparator
A class used for storing and showing game scores.

Fields Summary
private RMSGameScores
rmsgs
private RecordStore
recordStore
public static String
playerNameFilter
Constructors Summary
public RMSGameScores()
The constructor opens the underlying record store, creating it if necessary.

	//
	// Create a new record store for this example
	//
	try {
	    recordStore = RecordStore.openRecordStore("scores", true);
	}
	catch (RecordStoreException rse) {
	    System.out.println(rse);
	    rse.printStackTrace();
	}
Methods Summary
public voidaddScore(int score, java.lang.String playerName)
Add a new score to the storage.

param
score the score to store.
param
playerName the name of the play achieving this score.

	//
	// Each score is stored in a separate record, formatted with
	// the score, followed by the player name.
	//
	ByteArrayOutputStream baos = new ByteArrayOutputStream();
	DataOutputStream outputStream = new DataOutputStream(baos);
	try {
	    // Push the score into a byte array.
	    outputStream.writeInt(score);
	    // Then push the player name.
	    outputStream.writeUTF(playerName);
	}
	catch (IOException ioe) {
	    System.out.println(ioe);
	    ioe.printStackTrace();
	}

	// Extract the byte array
	byte[] b = baos.toByteArray();
	// Add it to the record store
	try {
	    recordStore.addRecord(b, 0, b.length);
	}
	catch (RecordStoreException rse) {
	    System.out.println(rse);
	    rse.printStackTrace();
	}
public intcompare(byte[] rec1, byte[] rec2)

	// Construct DataInputStreams for extracting the scores from
	// the records.
	ByteArrayInputStream bais1 = new ByteArrayInputStream(rec1);
	DataInputStream inputStream1 = new DataInputStream(bais1);
	ByteArrayInputStream bais2 = new ByteArrayInputStream(rec2);
	DataInputStream inputStream2 = new DataInputStream(bais2);
	int score1 = 0;
	int score2 = 0;
	try {
	    // Extract the scores.
	    score1 = inputStream1.readInt();
	    score2 = inputStream2.readInt();
	}
	catch (EOFException eofe) {
	    System.out.println(eofe);
	    eofe.printStackTrace();
	}
	catch (IOException eofe) {
	    System.out.println(eofe);
	    eofe.printStackTrace();
	}

	// Sort by score
	if (score1 < score2) {
	    return RecordComparator.PRECEDES;
	} else if (score1 > score2) {
	    return RecordComparator.FOLLOWS;
	} else {
	    return RecordComparator.EQUIVALENT;
	}
public voiddestroyApp(boolean cond)
destroyApp() This closes our open RecordStore when we are destroyed.

param
cond true if this is an unconditional destroy false if it is not (ignored here and treated as unconditional)

	System.out.println("destroyApp()");
	try {
	    if (recordStore != null)
		recordStore.closeRecordStore();
	} catch (Exception ignore) {
	    // ignore this
	}
public voidmain()

	rmsgs = new RMSGameScores();
	rmsgs.addScore(100, "Alice");
	rmsgs.addScore(120, "Bill");
	rmsgs.addScore(80, "Candice");
	rmsgs.addScore(40, "Dean");
	rmsgs.addScore(200, "Ethel");
	rmsgs.addScore(110, "Farnsworth");
	rmsgs.addScore(220, "Farnsworth");
	System.out.println("All scores");
	rmsgs.printScores();
	System.out.println("Farnsworth's scores");
	RMSGameScores.playerNameFilter = "Farnsworth";
	rmsgs.printScores("Farnsworth");
public booleanmatches(byte[] candidate)


    /*
     * Part of the RecordFilter interface.
     */
       
	 
    
	// If no filter set, nothing can match it.
	if (this.playerNameFilter == null) {
	    return false;
	}

	ByteArrayInputStream bais = new ByteArrayInputStream(candidate);
	DataInputStream inputStream = new DataInputStream(bais);
	String name = null;
	
	try {
	    int score = inputStream.readInt();
	    name = inputStream.readUTF();
	}
	catch (EOFException eofe) {
	    System.out.println(eofe);
	    eofe.printStackTrace();
	}
	catch (IOException eofe) {
	    System.out.println(eofe);
	    eofe.printStackTrace();
	}
	return (this.playerNameFilter.equals(name));
public voidpauseApp()
pauseApp()

	System.out.println("pauseApp()");
public voidprintScores()
This method prints all of the scores sorted by game score.

	try {
	    // Enumerate the records using the comparator implemented
	    // above to sort by game score.
	    RecordEnumeration re = recordStore.enumerateRecords(null, this, 
								true);
	    printScoresHelper(re);
	}
	catch (RecordStoreException rse) {
	    System.out.println(rse);
	    rse.printStackTrace();
	}
public voidprintScores(java.lang.String playerName)
This method prints all of the scores for a given player, sorted by game score.

	try {
	    // Enumerate the records using the comparator and filter
	    // implemented above to sort by game score.
	    RecordEnumeration re = recordStore.enumerateRecords(this, this, 
								true);
	    printScoresHelper(re);
	}
	catch (RecordStoreException rse) {
	    System.out.println(rse);
	    rse.printStackTrace();
	}
private voidprintScoresHelper(RecordEnumeration re)
A helper method for the printScores methods.

	try {
	    while (re.hasNextElement()) {
		int id = re.nextRecordId();
		ByteArrayInputStream bais = new 
		    ByteArrayInputStream(recordStore.getRecord(id));
		DataInputStream inputStream = new DataInputStream(bais);
		try {
		    int score = inputStream.readInt();
		    String playerName = inputStream.readUTF();
		    System.out.println(playerName + " = " + score);
		}
		catch (EOFException eofe) {
		    System.out.println(eofe);
		    eofe.printStackTrace();
		}
	    }
	}
	catch (RecordStoreException rse) {
	    System.out.println(rse);
	    rse.printStackTrace();
	}
	catch (IOException ioe) {
	    System.out.println(ioe);
	    ioe.printStackTrace();
	}
public voidstartApp()
startApp()

	System.out.println("startApp() - invoking main");
	// main() output is to System.out
	main();