Java : CSV

how to work with CSV Files

use opencsv library file
( https://mvnrepository.com/artifact/com.opencsv/opencsv)

import com.opencsv.CSVReader;
import com.opencsv.CSVWriter;

public class csv_file {
String sPath=".\\src\\test.csv";

public static void main(String[] args) throws IOException{
csv_file c=new csv_file();
ArrayList<String[]> data=new ArrayList<String[]>(); // Arraylist which stores string array type
String[] a_data={"hi","one"};
String[] a_data2={"this","is","50"};
data.add(a_data);
data.add(a_data2);
c.opencsv_writeAll(data);
System.out.println(c.opencsv_read());
}

public ArrayList<String[]> opencsv_readAll() throws IOException{
CSVReader csv = new CSVReader (new FileReader(sPath));
ArrayList<String[]> data=(ArrayList<String[]>) csv.readAll();
csv.close();
return data;
}
public ArrayList<String[]> opencsv_read() throws IOException{
CSVReader csv= new CSVReader (new FileReader(sPath));
ArrayList<String[]> data=new ArrayList<String[]>();

for(Iterator<String[]> i=csv.iterator();i.hasNext();)
data.add(i.next());
csv.close();
return data;
}

public void opencsv_writeAll(ArrayList<String[]> data) throws IOException{
CSVWriter csv= new CSVWriter (new FileWriter(sPath,true));
csv.writeAll(data);
csv.close();
}
public void opencsv_write(String[] data) throws IOException{
CSVWriter csv= new CSVWriter (new FileWriter(sPath,true));
csv.writeNext(data);
csv.close();
}

}

Java : Array List of Array ( ArrayList )

Array List of Array ( ArrayList<String[]> )

Example:

// Variable can be ArrayList<String[]> as well

List<String[]> AList= new ArrayList<String[]>();
String[] addressesArr = new String[3]; addressesArr[0] = "zero"; addressesArr[1] = "one"; addressesArr[2] = "two";

String[] addressesArr2 = {"hi", "there"};
AList.add(addressesArr);
AList.add(addressesArr2);

Java : (Swing) JTable

Java : (Swing) JTable

JTable : Used when more than 1 column is required

Pre -Req :

1. Make sure Window Builder addon is installed into eclipse
2. Create a New Swing Designer >app Window > Save
3. In Design Mode > add a JList Component 

Method 1:
DefaultTableModel model = new DefaultTableModel();
model.addColumn("A");
model.addColumn("B");

table = new JTable(model);
frame.getContentPane().add(table, BorderLayout.CENTER);
model.addRow(new Object[]{"1", "Deeapk"});

Method 2:

String[] Cols={"A" , "B"};
Object[][] data={
{"1","deepak"},
{"2","Alex"},
};

table = new JTable(data,Cols);
frame.getContentPane().add(table, BorderLayout.CENTER);

Code with Scroll bar :
frame = new JFrame();
DefaultTableModel model = new DefaultTableModel();
table = new JTable(model);
scrollPane = new JScrollPane(table);
scrollBar = new JScrollBar();

frame.setBounds(100, 100, 450, 300);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().setLayout(new BorderLayout(0, 0));
frame.getContentPane().add(scrollPane, BorderLayout.CENTER);

scrollPane.add(scrollBar);

model.addColumn("A");
model.addColumn("B");

for(int i=1;i<50;i++){
model.addRow(new Object[]{i, "Deeapk"});
}

 

Java : ( Swing ) Jlist

(Swing) JList

JTable : Used when only 1 column is required

Pre -Req :

1. Make sure Window Builder addon is installed into eclipse
2. Create a New Swing Designer >app Window > Save
3. In Design Mode > add a JList Component

DefaultListModel<String> listModel = new DefaultListModel<>();
            listModel.addElement("USA");
            listModel.addElement("India");
            listModel.addElement("Vietnam");

JList list = new JList(listModel);
 frame.getContentPane().add(list, "cell 0 1 7 4,grow");