Programming Forums > Application Development > Java

pr0gm3r · Sep 26th, 2005, 11:31 AM

HI guys,

I need your experties in java. I tried to insert some integer numbers from a file to an UnorderedLinkList class which is derived from LinkListClass class.

somehow the insertFirst(DataElement newItem) method in LinkListClass is not able to accept my data.
Error msg said "uncompatible type" -> inserftFirst(DataElement) to (int), but I have a derived class from DataElemet.

I have derived IntElemet from DataElement...

below is the main functions:

(Toggle Plain Text)

public static void main(String[] args)throws IOException
{
    UnorderedLinkList listItem = new UnorderedLinkList();
    IntElement num = new IntElement();
    BufferedReader infile = new BufferedReader(new   
    FileReader("TestLab3.data"));

    StringTokenizer tokenizer = new StringTokenizer(infile, " ");

    while(infile != null){
        num.setNum(Integer.parseInt(tokenizer.nextToken()));
        listItem.insertFirst(num);
    }
}

I tried to create an ADT link list that will accept all kinds of data type.

if you have any questions. please do not hesitate to ask.

Thank you in advance.

xavier · Sep 26th, 2005, 12:46 PM

I don't know about the linked list thing but . your reading from file ... i don't think it's going to work . Should be something like :

(Toggle Plain Text)

public static void main(String[] args)throws IOException
{
    UnorderedLinkList listItem = new UnorderedLinkList();
    IntElement num = new IntElement();
    BufferedReader infile = new BufferedReader(new   
    FileReader("TestLab3.data"));

   String line = "";

    while((line = infile.readLine()) != null){
        StringTokenizer tokenizer = new StringTokenizer(line, " ");
        while(tokenizer.hasMoreTokens()){
              num.setNum(Integer.parseInt(tokenizer.nextToken())  );
              listItem.insertFirst(num);
        }
    }
}

pr0gm3r · Sep 26th, 2005, 1:35 PM

Thanks...sorry I forgot to put the infile bufferedReader to a string. btw I am writting it on top of my head... I am don't have my actuall code handy..

btw I am not sure why the DataElemet are not compatibe with int. I thought DataElement is a generic data type...

thank you for all your help

pr0gm3r · Sep 27th, 2005, 12:12 PM

I got it to work... Thank you for your help and suggestions....

error was ... I tried to convert int datatype to DataElement datatype...
which is I suppose to derived IntElement class from DataElement.

IntElement is a class that will manipulate int datatype.

here is the full source code..
http://geocities.com/harry_tanama/Project.html

Sep 26th, 2005, 11:31 AM	#1
pr0gm3r Hobbyist Programmer Join Date: Dec 2004 Location: CA Posts: 102 Rep Power: 4	Unable to insert data to link list HI guys, I need your experties in java. I tried to insert some integer numbers from a file to an UnorderedLinkList class which is derived from LinkListClass class. somehow the insertFirst(DataElement newItem) method in LinkListClass is not able to accept my data. Error msg said "uncompatible type" -> inserftFirst(DataElement) to (int), but I have a derived class from DataElemet. I have derived IntElemet from DataElement... below is the main functions: (Toggle Plain Text) public static void main(String[] args)throws IOException { UnorderedLinkList listItem = new UnorderedLinkList(); IntElement num = new IntElement(); BufferedReader infile = new BufferedReader(new FileReader("TestLab3.data")); StringTokenizer tokenizer = new StringTokenizer(infile, " "); while(infile != null){ num.setNum(Integer.parseInt(tokenizer.nextToken())); listItem.insertFirst(num); } } public static void main(String[] args)throws IOException { UnorderedLinkList listItem = new UnorderedLinkList(); IntElement num = new IntElement(); BufferedReader infile = new BufferedReader(new FileReader("TestLab3.data")); StringTokenizer tokenizer = new StringTokenizer(infile, " "); while(infile != null){ num.setNum(Integer.parseInt(tokenizer.nextToken())); listItem.insertFirst(num); } } I tried to create an ADT link list that will accept all kinds of data type. if you have any questions. please do not hesitate to ask. Thank you in advance. __________________ -- pr0gm3r

Sep 26th, 2005, 12:46 PM	#2
xavier Professional Programmer Join Date: Oct 2004 Location: .ro Posts: 383 Rep Power: 4	I don't know about the linked list thing but . your reading from file ... i don't think it's going to work . Should be something like : (Toggle Plain Text) public static void main(String[] args)throws IOException { UnorderedLinkList listItem = new UnorderedLinkList(); IntElement num = new IntElement(); BufferedReader infile = new BufferedReader(new FileReader("TestLab3.data")); String line = ""; while((line = infile.readLine()) != null){ StringTokenizer tokenizer = new StringTokenizer(line, " "); while(tokenizer.hasMoreTokens()){ num.setNum(Integer.parseInt(tokenizer.nextToken()) ); listItem.insertFirst(num); } } } public static void main(String[] args)throws IOException { UnorderedLinkList listItem = new UnorderedLinkList(); IntElement num = new IntElement(); BufferedReader infile = new BufferedReader(new FileReader("TestLab3.data")); String line = ""; while((line = infile.readLine()) != null){ StringTokenizer tokenizer = new StringTokenizer(line, " "); while(tokenizer.hasMoreTokens()){ num.setNum(Integer.parseInt(tokenizer.nextToken()) ); listItem.insertFirst(num); } } } __________________ Don't take life too seriously, it's not permanent !

Sep 26th, 2005, 1:35 PM	#3
pr0gm3r Hobbyist Programmer Join Date: Dec 2004 Location: CA Posts: 102 Rep Power: 4	Thanks...sorry I forgot to put the infile bufferedReader to a string. btw I am writting it on top of my head... I am don't have my actuall code handy.. btw I am not sure why the DataElemet are not compatibe with int. I thought DataElement is a generic data type... thank you for all your help __________________ -- pr0gm3r

Sep 27th, 2005, 12:12 PM	#4
pr0gm3r Hobbyist Programmer Join Date: Dec 2004 Location: CA Posts: 102 Rep Power: 4	I got it to work... Thank you for your help and suggestions.... error was ... I tried to convert int datatype to DataElement datatype... which is I suppose to derived IntElement class from DataElement. IntElement is a class that will manipulate int datatype. here is the full source code.. http://geocities.com/harry_tanama/Project.html __________________ -- pr0gm3r

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Programming Forums > Application Development > Java

Unable to insert data to link list