Kim Lauwers

Hi everybody,

I have a maven2 question:

I have this pom file:
<dependencies> <dependency> <groupId>org.mule</groupId> <artifactId>mule-core</artifactId> <version>1.4.4</version> </dependency> <dependency> <groupId>org.mule.modules</groupId> <artifactId>mule-module-client</artifactId> <version>1.4.4</version> </dependency> <dependency> <groupId>org.mule</groupId> <artifactId>mule-core</artifactId> <version>2.1.2</version> </dependency> <dependency> <groupId>org.mule.modules</groupId> <artifactId>mule-module-client</artifactId> <version>2.1.2</version> </dependency> </dependencies>

Now I want to have mule version 1.4.4 AND mule version 2.1.2 on my classpath. But because of the fact that the groupid and artifactid are the same. Maven only puts the the first one on my classpath.
Can this be fixed?

Thanks,
Greetings Kim.

Originally posted by Jeffry Kristianto Yanuar:
I think most of the candidates use ActionListener. You just decide how to use the ActionListener.

I implement inner classes that implements ActionListener such as BookButtonListener, SearchButtonListener, ExitButtonListener, etc. Judging from its name, you can figure out what the functionality of these classes.

Thanks for the reply. I use the same kind of namingconvention as you, but I never user inner classes. A always create a new class/file. This is my personnal favor, but I don't know if there is another reason to use inner classes or not.

Greetz,
Kim

What the difference between the two?
Which one should i favor?

Here what I think / know

ActionListener:
---------------
Action:
-------

Is an extension of the ActionListener

Abstraction of a command, where no UI component is linked at.

You can use different UI components with the same action.

Pays the price on memory and performance.

I always use actions and this because the assignment says:

Your user interface should be designed with the expectation of future functionality enhancements, and it should establish a framework that will support this with minimal disruption to the users when this occurs.

So action are the best I think.


Or have I a wrong vision?

thanks,
Kim

Congrats with your great result.

As I didn't expect I lost marks in GUI which makes me regret not putting more usability features in the UI (and my work domain is UI ).

What do you mean this, I mean I have the assigment URLyBird and the demands for GUI are so simple. I don't know sure what you mean by usability features? I'm afraid if you do something, you will lose points for making it to difficult / to wide.

Greetz,
Kim

I think both options are great.

1) Keeping in memory (that's what I do)
or
2) Always closing and opening the file.

It just depends on how you motivate your choice in choices.txt.

I motivate, that I think the database will never grow to that size, It's to big to keep in memory.

Greetz,
Kim

Originally posted by Alecsandru Cocarla:
Why do you need to know how many rows are in the database?

You're right, my mistake

Thanks

May I let Eclipse generate the serial ID or do I really have to use the date?

If not:
I read that you must use the current time. So would this be good:
private static final long serialVersionUID = new Date().getTime();

Thanks
Kim

Congrats !!!

Thank you,

I probably will only support update and search on the GUI, but implement the complete back-end.

Greetz,
Kim

Hi Guys,

Another question. Below a simplified view of my data layer.

public class RoomRepository { private DBAccess dbAccess; }

DBAccess is the given interface from the assigment

public class Data implements DBAccess{ private FlatAccessFile file; }

public class FlatAccessFile{ private RandomAccessFile database; }

So I have a class RoomRepository, which I use in my GUI. This class works with HotelRooms. My repository does the convertion from a HotelRoom to a String[]. I have a Field in this class of type Data (which is the given interface). The class Data implements the given interface and requires String[]. My Data contains a basic cache. My Data-class also contains a variable of type FlatAccessFile. The FlatAccessFile does the actual read and write operations on my RandomAccessFile.

Now for a JTable I need to know how many rows there are in my database. In my case this information is know by the FlatAccessFile. But eventually my roomRepository needs this knowledge. How can I give this information to the repository.

1) May I add methods to the DBAccess interface? a method getRowcount or something like that?

2) I can add the the method to Data-class and in my repository use a field dbAccess of type Data and not of the type DBAccess (Given Interface)

How did you solve this? Has anyone has an opion at this problem?

Thanks in advance.

Greetz,
Kim
[ November 25, 2008: Message edited by: Kim Lauwers ]

Hi Guys,

A little question about the URLyBird assignment.

- The assignment doesn't say you must be able to add a record, but my DBAccess interface has the method to create one. Do you guys implement it, or just put in choices.txt that it was out of scope.

- For updating, removing, ... a certain record. Is the only view you guys have is the JTable? Or do you create a nice form for updating a certain record?

Thanks in advance.

Greetings,
Kim

Hey Mike,

My code isn't nice modelled, I'm just trying to find out how to read my databasefile.

In my interface I need to implement I have the method:
public String[] readRecord(long locationInFile)

So I assume that this String[] contains all the fields of one record.

But I just can't seem the read the databasefile correct.

Greetz,
Kim

Alex thanks for the input.

But I'm having really difficulties with how to read the database file, that is provided with the assignment.

public class Repository { private static final String DATABASE_NAME = "database.db"; private static DataInputStream database = null; private Logger log = Logger.getLogger(Repository.class.getName()); public Repository(String dbPath) throws IOException { String path = dbPath + File.separator + DATABASE_NAME; database = new DataInputStream(new FileInputStream(path)); log.fine("Database opened (" + path + ") with mode rw"); } public String[] readRecord(long locationInFile) throws IOException { final byte[] input = new byte[Room.RECORD_LENGTH]; synchronized (database) { database.readFully(input); } String[] record = new String[7]; RoomRecordReader roomRecordReadar = new RoomRecordReader(input); int i = 0; record[i++] = roomRecordReadar.read(Room.HOTEL_TITLE_LENGTH); record[i++] = roomRecordReadar.read(Room.CITY_LENGTH); record[i++] = roomRecordReadar.read(Room.OCCUPANCY_LENGTH); record[i++] = roomRecordReadar.read(Room.SMOKING_LENGTH); record[i++] = roomRecordReadar.read(Room.PRICE_LENGTH); record[i++] = roomRecordReadar.read(Room.DATE_LENGTH); record[i++] = roomRecordReadar.read(Room.OWNER_LENGTH); return record; } }
RoomRecordReader.java
/** * class to assist in converting from the one big byte[] into multiple String[] - * one String per field. */ public class RoomRecordReader { /** field to track the position within the byte array */ private int offset = 0; private byte[] input; public RoomRecordReader(byte[] input) { this.input = input; } /** * converts the required number of bytes into a String. * * @param length * the length to be converted from current offset. * @return the converted String * @throws UnsupportedEncodingException * if "UTF-8" not known. */ String read(int length) throws UnsupportedEncodingException { String str = new String(input, offset, length, "UTF-8"); offset += length; return str.trim(); } }
Room.java
public class Room { /** * The maximum length of the hotel name we will store. */ public static final int HOTEL_TITLE_LENGTH = 64; /** * The maximum length of the city we will store. */ public static final int CITY_LENGTH = 64; /** * The maximum length of the occupancy we will store. */ public static final int OCCUPANCY_LENGTH = 4; /** * The maximum length of smoking allowed we will store. */ public static final int SMOKING_LENGTH = 1; /** * The maximum length of price-field allowed we will store. */ public static final int PRICE_LENGTH = 8; /** * The maximum length of date-field allowed we will store. */ public static final int DATE_LENGTH = 10; /** * The maximum length of owner-field allowed we will store. */ public static final int OWNER_LENGTH = 8; /** * The size of a complete record in the database. Calculated by adding * all the previous fields together. Knowing this makes it easy to work * with an entire block of data at a time (rather than reading * individual fields), reducing the time we need to block on database * access. */ public static final int RECORD_LENGTH = HOTEL_TITLE_LENGTH + CITY_LENGTH + OCCUPANCY_LENGTH + SMOKING_LENGTH + PRICE_LENGTH + DATE_LENGTH + OWNER_LENGTH; }


And if I use a testclass to print the output of the file:
public static void main(String[] args) throws Exception { Repository repository = new Repository("C:/SCJD"); String[] strings = repository.readRecord(1); for (String string : strings) { System.out.println(string); } }

But I get a none clear output, so it seems that i'm reading my file incorrect.

Can someone assist me with this?

Thanks,
Kim

Hello everybody,

I received the assigment for the SCJD Java 5 today.

But now i'm having problems with starting. I hope you guys can help answering a few questions.

1. How do I start best with the assignment: Do I start from the GUI and develop from there all that is needed, or do I start with the interface I received from SUN?

2. I'm having big problems with SUN's interface. Let me explain with an example from the interface:
/** * Returns an array of record numbers that match the specified criteria. * Field n in the database file is described by criteria[n]. A null * value in criteria[n] matches any field value. A non-null value in * criteria[n] matches any field value that begins with criteria[n]. * (For example, "Fred" matches "Fred" or "Freddy".) */ public long[] findByCriteria(String[] criteria);
How stupid is this interface, do I have to put an fa�ade or so before this interface so my code works with Collections and Objects instead of array's and id's of records?

3. How do you start with the random access file? Is there a good site or post on the forum, where this topic is cleared out (thinking about concurrency and stuff). And perhaps the most important, is there an editor or so that I can use to read te file?

Thanks in advance.

Greetz,
Kim

I can't install it.

It says It can't install on a 16 bit windows system or something

"The system file is not suitable for running MS-DOS and Microsoft Windows appl"

And yes I have downloaded the windows version

Greetz