在JTable中显示arrayLists的arrayList

Question

I have an arraylist and each element of the arrayList contains a small arrayList of data.

I need to create a table from this data. What would you recommend being the best route to take with solving this?

Thanks in advance for any help

Answer 1

See How to create a Table Model

A small example showing how to create a Model and store your objects in the model. Any operation on the data should be done using the model.

Create a model and use a list to store the data for that table. As shown in the below example. Each of the row in the table is a Student object and each object is stored in the list. Traverse the list and get each object and show in the table. This is done using getValueAt(..) method.

import java.awt.EventQueue;
import java.util.ArrayList;
import java.util.List;

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


public class JTableList {
    public static void main(String[] args) {

        Runnable r = new Runnable() {

            @Override
            public void run() {
                CustomModel model = new CustomModel();
                JTable table = new JTable();
                table.setModel(model);

                JFrame frame = new JFrame();
                frame.add(new JScrollPane(table));
                frame.pack();
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setVisible(true);             
            }
        };

        EventQueue.invokeLater(r);
    }

}

class CustomModel extends AbstractTableModel {

    List<Student> data;
    String[] columnNames = {"Name", "Age"};

    public CustomModel() {
        data = new ArrayList<Student>();

        data.add(new Student("Amar", 1));
        data.add(new Student("Sam", 2));
        data.add(new Student("Amar", 1));
        data.add(new Student("Sam", 2));
        data.add(new Student("Amar", 1));
        data.add(new Student("Sam", 2));


    }

    @Override
    public String getColumnName(int column) {
        return columnNames[column];
    }

    @Override
    public int getColumnCount() {
        return 2;
    }

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

    @Override
    public Object getValueAt(int rowIndex, int columnIndex) {
        Student student = data.get(rowIndex);
        switch (columnIndex) {
        case 0:
            return student.getName();
        case 1:
            return student.getAge();
        default:
            return null;
        }
    }

}

class Student {
    private String name;
    private int age;

    public Student(String name, int age) {
        this.name = name;
        this.age = age;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
}

Answer 2

To display a GUI table of a List of lists, I would create a class that implements the 'TableModel' interface, and has a constructor that takes in your 'List>'

public class ListTableModel <T> implements TableModel {

    private List<List<T>> source;

    public ListTableModel(List<List<T>> source) {

        this.source = source;

    }


    //Override 'getRowCount' 
    //The row count would be calculated as the size of the outer list.
    @Override
    public int getRowCount() {
        return source.size();
    }

    //Override 'getColumnCount'
    //The column count would be calculated as the max size of the inner lists
    @Override
    public int getColumnCount() {
        int max = 0;
        for(List<T> row : source) {
            max = Math.max(max, row.size());
        }
        return max;
    }

    //Override 'getColumnName'
    //Lets go ahead and just give a unique name to each column based on the index.
    //This could be populated from an input taken by the constructor, but we
    //won't worry about that now.
    @Override
    public String getColumnName(int columnIndex) {
        return "Column " + columnIndex;
    }

    //Override 'getColumnClass'
    //The class would technically be the generic type 'T', so to get this we 
    //will simply just get the calss of the first element.
    @Override
    public Class<?> getColumnClass(int columnIndex) {
        return source.get(0).get(0).getClass();
    }


    //Override 'isCellEditable'
    //I'm going to assume we don't want cell to be editable.
    @Override
    public boolean isCellEditable(int rowIndex, int columnIndex) {
        return false;
    }

    @Override
    public Object getValueAt(int rowIndex, int columnIndex) {
        List<T> row = source.get(rowIndex);
        if(columnIndex >= row.size())
            return null;
        else 
            return row.get(columnIndex);
    }

    @Override
    public void setValueAt(Object aValue, int rowIndex, int columnIndex) {
        //required but we will assume that you cannot change the source list
        //if we needed to, it wouldn't be too difficult to implement.
    }

    @Override
    public void addTableModelListener(TableModelListener l) {
        //required but not used (will only be used if the source could change)
    }

    @Override
    public void removeTableModelListener(TableModelListener l) {
        //required but not used (will only be used if the source could change)
    }

}

you would use this model with your list like so:

List<List<String>> myList = new ArrayList();

//Populate 'myList'...

JTable table = new JTable();

//Add table to view...

table.setModel(new ListTableModel(myList));

EDIT I can show you how to implement TableModel if you would like.

Answer 3

The List Table Model can be used to do this.

It is a more complex and flexible solution implementing the earlier suggestions given in this thread.