Create jTable with ArrayList

Question

I searched for a while but I cant find a solution for my problem.

I want to display the Values of an ArrayList in a JTable, i'm pretty new to this and cant fix the error.

package Statistik;

import java.util.ArrayList;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;

public class Statistic {

    private static ArrayList<String> rowA = new ArrayList();
    private static ArrayList<String> rowB = new ArrayList();
    private static ArrayList<String> rowC = new ArrayList();
    private static ArrayList<String> titel = new ArrayList();
    private static ArrayList<Object> table = new ArrayList();

    public static void main(String[] args) {

        titel.add("Name");
        titel.add("Art der Bearbeitung");
        titel.add("Datum");

        addRows("buchung", "Created", "10.10.10");
        addRows("buchung", "Created", "10.10.10");
        addRows("buchung", "Created", "10.10.10");
        addRows("buchung", "Created", "10.10.10");
        addRows("buchung", "Created", "10.10.10");

        table.add(rowA);
        table.add(rowB);
        table.add(rowC);


        // Das JTable initialisieren
        JTable EndTable = new JTable( table , titel );

        JFrame frame = new JFrame( "Demo" );
        frame.getContentPane().add(new JScrollPane( EndTable ) );
        frame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
        frame.pack();
        frame.setVisible( true );
    }

    public static void addRows(String rowa, String rowb, String rowc) {

        rowA.add(rowa);
        rowB.add(rowb);
        rowC.add(rowc);

    }

}

I can't set the ArrayList table as first Value in my EndTable, but i dont know how I should do otherwise.

Thank you all for trying to answer my problem.

Edit

My goal is to make a List with

Entity-Name, art of change, Date

so I thought it would be the best to use an ArrayList because it's flexible. It have to be flexible because we dont know how much the user will change.

Answer 1

Nope since , JTable has no reserved argument for ArrayList, but a trick will solve it ! you know that the arguments for JTable is also (Object[][], object[])

      Object[] tempTitel = titel.toArray(); // return Object[]

      String[][] tempTable = new String[table.size()][]; 

     int i = 0;
     for (List<String> next : table) {
      tempTable[i++] = next.toArray(new String[next.size()]); // return Object[][]
    }



   JTable EndTable = new JTable(tempTable,tempTitel);

Note that I change ArrayList<String> table= new ArrayList() to ArrayList<ArrayList<String>> table = new ArrayList(); so when combine it :

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;

public class Statistic {

    private static ArrayList<String> rowA = new ArrayList();
    private static ArrayList<String> rowB = new ArrayList();
    private static ArrayList<String> rowC = new ArrayList();
    private static ArrayList<String> titel = new ArrayList();
    private static ArrayList<ArrayList<String>> table = new ArrayList();

    public static void main(String[] args) {

        titel.add("Name");
        titel.add("Art der Bearbeitung");
        titel.add("Datum");

        addRows("buchung", "Created", "10.10.10");
        addRows("buchung", "Created", "10.10.10");
        addRows("buchung", "Created", "10.10.10");
        addRows("buchung", "Created", "10.10.10");
        addRows("buchung", "Created", "10.10.10");

        table.add(rowA);
        table.add(rowB);
        table.add(rowC);

          Object[] tempTitel = titel.toArray();
          String[][] tempTable = new String[table.size()][];
       int i = 0;
       for (List<String> next : table) {
       tempTable[i++] = next.toArray(new String[next.size()]);
        }

       JTable EndTable = new JTable(tempTable,tempTitel);

        JFrame frame = new JFrame("Demo");
        frame.getContentPane().add(new JScrollPane(EndTable));
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setVisible(true);
    }

    public static void addRows(String rowa, String rowb, String rowc) {

        rowA.add(rowa);
        rowB.add(rowb);
        rowC.add(rowc);

    }

}

Answer 2

You should create custom TableModel for your table see the following link for more details Custom JTable Model

Here's some code to start with:

import java.util.ArrayList;
import java.util.Date;
import java.util.List;

import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.AbstractTableModel;

public class Test extends JFrame {
    public Test() {
        setBounds(100, 100, 500, 400);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JTable table = new JTable(new ModelData());
        add(new JScrollPane(table));
        setVisible(true);
    }

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

class ModelData extends AbstractTableModel {
    List<Data> data = new ArrayList<Data>();
    String colNames[] = { "Name", "Type", "Date" };
    Class<?> colClasses[] = { String.class, String.class, Date.class };

    ModelData() {
        data.add(new Data("name 1", "type 1", new Date()));
        data.add(new Data("name 2", "type 2", new Date()));
        data.add(new Data("name 3", "type 3", new Date()));
    }

    public int getRowCount() {
        return data.size();
    }

    public int getColumnCount() {
        return colNames.length;
    }

    public Object getValueAt(int rowIndex, int columnIndex) {
        if (columnIndex == 0) {
            return data.get(rowIndex).getName();
        }
        if (columnIndex == 1) {
            return data.get(rowIndex).getType();
        }
        if (columnIndex == 2) {
            return data.get(rowIndex).getDate();
        }
        return null;
    }

    public String getColumnName(int columnIndex) {
        return colNames[columnIndex];
    }

    public Class<?> getColumnClass(int columnIndex) {
        return colClasses[columnIndex];
    }

    public boolean isCellEditable(int rowIndex, int columnIndex) {
        return true;
    }

    public void setValueAt(Object aValue, int rowIndex, int columnIndex) {
        if (columnIndex == 0) {
            data.get(rowIndex).setName((String) aValue);
        }
        if (columnIndex == 1) {
            data.get(rowIndex).setType((String) aValue);
        }
        if (columnIndex == 2) {
            data.get(rowIndex).setDate((Date) aValue);
        }
        fireTableCellUpdated(rowIndex, columnIndex);
    }
}

class Data {
    String name;
    String type;
    Date date;

    public Data(String name, String type, Date date) {
        super();
        this.name = name;
        this.type = type;
        this.date = date;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getType() {
        return type;
    }

    public void setType(String type) {
        this.type = type;
    }

    public Date getDate() {
        return date;
    }

    public void setDate(Date date) {
        this.date = date;
    }
}

And this is the result:

Answer 3

Perhaps you should post your error. I can see from JTable constructor in the Java API that it does not take an ArrayList as arguments.

JTable(Object[][] rowData, Object[] columnNames) Constructs a JTable to display the values in the two dimensional array, rowData, with column names, columnNames.

Perhaps you should try using primitive arrays?