Question

My jtable should read a text file and show them.

It reads all data correctly, But just show last line record in file, in its all rows repetitive.

Where is my mistake?

My text file:

uiui     898     666999
vvvv     6666     7777
hfsn     5356     56
ds     232     2212
bbnn     2013     211

My AllBooks Class:

public class AllBooks extends AbstractTableModel{

BookInformation Binfos=new BookInformation();

String[] Bcol=new String[]{"Name","Date","Id"};
List<BookInformation> Bdata=new ArrayList<BookInformation>();

public AllBooks(){
    try{
        FileReader fr=new FileReader("AllBookRecords.txt");
        BufferedReader br=new BufferedReader(fr);
        String line;

        while( (line=br.readLine()) !=null){
            Bdata.add(initializeUserInfos(line));
        }
        br.close();
    }
    catch(IOException ioe){

    }
}

public BookInformation initializeUserInfos(String str){
    System.out.println(str);
    String[] bookCellArray=str.split("     ");
    Binfos.setBookName(bookCellArray[0]);
    Binfos.setBookDate(bookCellArray[1]);
    Binfos.setBookID(bookCellArray[2]);
    return Binfos;
}


@Override
public String getColumnName(int col){
    return Bcol[col];
}

@Override
public int getRowCount() {
    if(Bdata !=null){
    return Bdata.size();
    }
    else{
        return 0;
    }
}

@Override
public int getColumnCount() {
    return Bcol.length;
}

@Override
public Object getValueAt(int rowIndex, int columnIndex) {
    BookInformation binfo=Bdata.get(rowIndex);
    Object value;

    switch(columnIndex){

        case 0:
            value=binfo.getBookName();
            break;
        case 1:
            value=binfo.getBookDate();
            break;
        case 2:
            value=binfo.getBookID();
            break;
        default :
            value="...";  
    }
    return value;

}

}

My AllBooksM Class:

public class AllBooksM {
   final AllBooks rbftl=new AllBooks();
   final JFrame Bframe=new JFrame("All Book List");
   final JTable Btable=new JTable(rbftl);


public AllBooksM(){

    JPanel Bpanel=new JPanel();
    Bpanel.setLayout(new FlowLayout());
    JScrollPane sp=new JScrollPane(Btable); 
    Bpanel.add(sp);
    Bframe.add(Bpanel);
    Btable.setAutoCreateRowSorter(true);
    Bframe.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    Bframe.setBounds(300, 60, 550, 550);
    Bframe.setResizable(false);
    Bframe.setVisible(true);
}


public static void main(String[] args){
    new AllBooksM();
}
}

My BookInformation Class:

public class BookInformation {

private String BookName;
private String BookDate;
private String BookID;

public String getBookName() {
    return BookName;
}

public void setBookName(String book_name) {
    this.BookName = book_name;
}

public String getBookDate() {
    return BookDate;
}


public void setBookDate(String book_date) {
    this.BookDate = book_date;
}


public String getBookID() {
    return BookID;
}

public void setBookID(String Book_id) {
    this.BookID = Book_id;
}

}

Thanks!

Answer 1

You’re using the same BookInformation object with each iteration of the while loop and instead need to create a new one with each iteration. Else that same object will be held by all rows of the table model causing the same information will be displayed on every row.

For instance you can solve it by doing something like this.

public BookInformation initializeUserInfos(String str){
    System.out.println(str);
    String[] bookCellArray=str.split("     ");

    // create and use a local BookInformation variable and object:
    BookInformation bInfos = new BookInformation(); // *****

    bInfos.setBookName(bookCellArray[0]);
    bInfos.setBookDate(bookCellArray[1]);
    bInfos.setBookID(bookCellArray[2]);
    return bInfos;
}