Question

Note: Fall_2e17.java uses or overrides a deprecated API Note: Recompile with -Xlint:deprecation for details.

I am getting this Error can you please fix my Java code.

import java.awt.Dialog;

import java.awt.Label;

import java.awt.TextArea;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.util.ArrayList;

import java.util.HashMap;

import java.util.List;

import java.util.Map.Entry;

import javax.swing.JButton;

import javax.swing.JFrame;

import javax.swing.JPanel;

public class Fall_2017 {
  
public TextArea courseInput;
  
public Label textAreaLabel;
  
public JButton addData;
  
public Dialog confirmDialog;
  
HashMap<Integer, ArrayList<String>> students;
  
public Fall_2017(){
  
courseInput = new TextArea(20, 40);
  
textAreaLabel = new Label("Student's data:");
  
addData = new JButton("Add Data");
  
addData.addActionListener(new ActionListener()
{
  
@Override
  
public void actionPerformed(ActionEvent e) {
  
confirmDialog.show();
  
}
  
});

createGUI();
  
}
  
public void createGUI(){
  
JFrame frame = new JFrame("Student's Data");
  
frame.setVisible(true);
  
frame.setSize(500, 500);
  
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  
JPanel panel = new JPanel();
  
panel.add(textAreaLabel);
  
panel.add(courseInput);
  
panel.add(addData);
  
frame.getContentPane().add(panel);
  
initialiseConfirmDialog(frame);
  
}
  
private void initialiseConfirmDialog(JFrame frame) {
  
confirmDialog = new Dialog(frame);
  
JPanel panel = new JPanel();
  
panel.add(new Label("Do you want to add more students?"));
  
JButton yesButton = new JButton("Yes");
  
JButton noButton = new JButton("No");
  
yesButton.addActionListener(new ActionListener()
{
  
@Override
  
public void actionPerformed(ActionEvent e) {

confirmDialog.hide();
  
}
  
});
  
noButton.addActionListener(new ActionListener()
{
  
@Override
  
public void actionPerformed(ActionEvent e) {
  
confirmDialog.hide();

String text = courseInput.getText();
  
processCourse(text);
  
courseInput.setText("");
}
} );
  
panel.add(yesButton);
  
panel.add(noButton);
  
confirmDialog.add(panel);
  
confirmDialog.setSize(200, 100);
  
}
  
private void processCourse(String text) {
  
students = new HashMap<>();
  
for(String studentData:text.split("\n")){
  
String[] data = studentData.split(" ");
  
if(students.containsKey(Integer.parseInt(data[0]))){
  
students.get(Integer.parseInt(data[0])).add(data[1]);
  
}else{
  
ArrayList<String> courses = new ArrayList<>();
  
courses.add(data[1]);
  
students.put(Integer.parseInt(data[0]), courses);
  
}
  
}
  
for(Entry<Integer,ArrayList<String>> entry:students.entrySet()){
  
System.out.println(entry.getKey());
  
System.out.println(entry.getValue());
  
System.out.println();
  
}
  
}
  
public static void main(String[] args) {
  
Fall_2017 gui = new Fall_2017();
  
}

}

Answer 1

This is not an error , its a warning message.

recompiler with the below syntax

javac -Xlint xzy.java //provide java file name

you can also try below option.

javac -Xlint:deprecation xyz.java