I have an ArrayList containing 100 values.
al = "AA","BB","CC","DD","EE","FF"... upto 100 values
I need to insert these values in a jTable having 2 columns and 50 rows i.e.
col1 col2
AA BB
CC DD
EE FF
... ...
upto 50 rows
How do I get that (preferably using loops)? Need a generic solution because number of elements or rows can vary.
Here's what you need . I know this may not be the optimized way, Still try this:
package App;
import java.util.ArrayList;
import java.util.List;
import javax.swing.table.AbstractTableModel;
public class JtableModel extends AbstractTableModel {
List list, oddList, evenList;
String col_names[] = {"First", "Second"};
public JtableModel(List list) {
this.list = list;
}
public void myFormatting(){
this.oddList = new ArrayList();
this.evenList = new ArrayList();
for (int i = 0; i < list.size(); i++) {
if (i % 2 == 0) {
this.evenList.add(list.get(i));
} else {
this.oddList.add(list.get(i));
}
}
}
@Override
public int getRowCount() {
return evenList.size();
}
@Override
public int getColumnCount() {
return col_names.length;
}
@Override
public Object getValueAt(int rowIndex, int columnIndex) {
switch (columnIndex) {
case 0:
try {
return evenList.get(rowIndex);
} catch (Exception e) {
}
case 1:
try {
return oddList.get(rowIndex);
} catch (Exception e) {
//find out how you can validate this
}
}
return new String();
}
}
And the Snippet of java File generate with NetBeans :
public class JtableDemo extends javax.swing.JFrame {
/**
* Creates new form JtableDemo
*/
public JtableDemo() {
initComponents();
fillTbl();
}
public void fillTbl(){
ArrayList arr = new ArrayList();
arr.add("AA");
arr.add("BB");
arr.add("CC");
arr.add("DD");
arr.add("EE");
JtableModel tableModel = new JtableModel(arr);
tableModel.myFormatting();
jTable1.setModel(tableModel);
}
arr in two sublists is completely unnecessary and a waste of memory and time.i'd simply convert the arraylist in an 2 dimensional array ...
somethin like that
public void convertToArray(){
int count = 0;
for (int j = 0; j < entrys.length; j++) {
for (int i = 0; i < 2; i++) {
entrys[j][i] = list.get(count++);
}
}
}
then create the table
String[] header = {"col1", "col2"};
table = new JTable(entrys, header);
and add to frame etc.
More or less :
import java.util.ArrayList;
import javax.swing.*;
import javax.swing.table.DefaultTableModel;
public class NewClass extends JFrame {
private JTable table;
private DefaultTableModel model;
private JScrollPane scroll;
private String headers[] = {"col1","col2"};
String[] data = {"AA", "BB", "CC", "DD", "EE", "FF","GG","HH","II","JJ","KK","LL","MM","NN","OO","PP","QQ","RR"};
public NewClass() {
model = new DefaultTableModel();
model.setColumnIdentifiers(headers);
table = new JTable();
table.setModel(model);
scroll = new JScrollPane(table);
insert();
add(scroll, java.awt.BorderLayout.CENTER);
setSize(300, 300);
setVisible(true);
}
public void insert(){
ArrayList<String> ar = new ArrayList<String>();
for (int i = 0; i < data.length; i++) {
ar.add(data[i]);
}
for (int i=0;i<(ar.size()/2);i++) {
model.addRow(new Object[] { String.valueOf(ar.get(2*i)) , String.valueOf( ar.get((2*i)+1)) });
}
}
public static void main(String[] args) {
new NewClass();
}
}
