Problem with the download

[Daniel Sablosky]

When I tried to open the assignment, I received the message: the file you are opening cannot be opened by the default program. It is either corrupted or has an incorrect file type. As a security precaution it is recommended that you cancel the download.



When I tried to open the assignment after I saved it, I got a window labeled Java Virtual Machine Launcher and a message that says:



Failed to load Main-Class manifest attribute from C:\Documents and Settings\Dan\My Documents\zsr1578510 af1.jar



I opened the assignment with the IDE. I was able to read the instructions.html, but the database was just in binary and it didn�t give me any other options to open with.



Please help. Thanks.

[mohamed sulibi]

hi;

as i think the download file ext is .jar , OK ? , so you must open it
winRAR or winzip program, also you can alter the ext to .zip.
and then unzip it, so you found two files , 1- instraction.html and 2- db2db.db files, this database file contain binary data not ascii so you
must open it in ultraedit or any other software that open binary data.

BR;
M_darim.
SCJP, SCJD in progress ..

[Daniel Sablosky]

Thank you very much. I was able to get inside the folder with WinZip. However, I was unable to open db-1X2 with MS Access. I received the message: Externable data is not in the expected format. What program should I use to open db-1x2? Any help would be greatly appreciated. Thanks.

[Abdulvakhid Shoudouev]

I'm afraid MS Access is useless here.

Try RandomAccessFile:

            RandomAccessFile raf  = new RandomAccessFile("db-1x2.db", "r");

To read 4 byte numeric fields use raf.readInt() (int is stored using 4 bytes).
For example:

         
            int cookie = raf.readInt();
            int recordLength = raf.readInt();

To read 2 byte numeric fields use raf.readShort():
For example:

            short numberOfFields = raf.readShort();
            short fieldNameLength = raf.readShort();
            short fieldLength = raf.readShort();

To read name of the field you can try something like that:

                short fieldNameLength = raf.readShort();
                byte[] fieldName = new byte[fieldNameLength];
                raf.read(fieldName);

[ January 13, 2008: Message edited by: Abdulvakhid Shoudouev ]
[ January 13, 2008: Message edited by: Abdulvakhid Shoudouev ]

[Andrew Monkhouse]

as i think the download file ext is .jar , OK ? , so you must open it winRAR or winzip program, also you can alter the ext to .zip.

Alternatively you could use the jar program to open the jar file.

Try running "jar" on your command line - you should see all the command line options. One of them is 'x' for extract.

Regards, Andrew

[rohan tiwari]

I downloaded about 5 days back.I did the same thing , used jar on the command line with x for extract.

[mohamed sulibi]

hi all;

thunk to you , how can i miss that, jar command.

to open the binary file as is , use EmEditor application or UltraEdit application to see your file, these application provide you a view in Hex
format that make you see your data in binary and in Hex,
please send to me your email and i will send to you these applications.

BR;
SCJP, SCJD in progress B&S ...

[mohamed sulibi]

hi all;

thunk to you , how can i miss that, jar command.

to open the binary file as is , use EmEditor application or UltraEdit application to see your file, these application provide you a view in Hex
format that make you see your data in binary and in Hex,
please send to me your email and i will send to you these applications.

BR;
SCJP, SCJD in progress B&S ...