okay look i know this question has been answered time and time again HOWEVER i seriously can't figure out what im doing wrong.
please help.
i have two classes. Machine.java which is the object class and the InventoryTest.java class that holds the main statement.
everywhere i have read says this should work.
this is in the Machine.java class
public static Comparator<Machine> machineIdNumberComparator = new Comparator<Machine>() {
@Override
public int compare(Machine s1, Machine s2) {
String MachineID1 = s1.getMachineIdNumber();
String MachineID2 = s2.getMachineIdNumber();
//ascending order
return MachineID1.compareTo(MachineID2);
}};
this is in the InventoryTest
Collections.sort(arraylist, inventoryArray.machineIdNumberComparator);
this line comes up with problems. arraylist has cannot find symbol error and so does the machineIdNumberComparator.
i need to be able to sort by 3 different methods.
edit: this is how i add and created my arrayList
public List<Machine> inventoryArray = new ArrayList<>();
inventoryArray.add(new Machine(strMachineIdNumber, strManufacturer, strType, dblPowerOrCapacity, dblPrice));
the arraylist is declaired at the start just under the public class where you declair all your variables.
/**
*
* @author stephankranenfeld
*/
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.List;
import java.util.Collections;
import java.util.Comparator;
import java.util.NoSuchElementException;
import java.util.Scanner;
import java.util.StringTokenizer;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.*;
import javax.swing.JButton;
import javax.swing.JTextArea;
public class InventoryTest extends JFrame {
private static final int FRAME_WIDTH = 800;
private static final int FRAME_HEIGHT = 1500;
private final JTextArea textArea;
private final JButton addMachine;
private final JButton removeMachine;
private final JButton exitButton;
private final JButton sortButton;
final String START_TEXT = String.format("%-20s %-20s %-10s %15s %10s %n", "Machine ID Number:", "Manufacturer:", "Type:", "Power/Capacity:", "Price:"); // starting line of texted used in both display all and entre data buttons.
final String DEVIDER = "-------------------------------------------------------------------------------------\n";// a devider used multple times
public List<Machine> inventoryArray = new ArrayList<>();
/*
junk that isn't needed i think
*/
private void sort() {
JComboBox sortBy = new JComboBox();
sortBy.addItem("ID Number");
sortBy.addItem("Manufacturer");
sortBy.addItem("Type");
int option = JOptionPane.showConfirmDialog(null, sortBy, "Sort by?", JOptionPane.OK_CANCEL_OPTION);
if (option == JOptionPane.OK_OPTION)
{
//if id is selected sort by id
//if manufacturer is selected sor by manufacturer
//if type is selected sort by type
Collections.sort(inventoryArray, Machine.machineIdNumberComparator);
}
}
}
public class Machine{
/*
* all the get and set methods
*/
public static Comparator<Machine> machineIdNumberComparator = new Comparator<Machine>() {
@Override
public int compare(Machine s1, Machine s2) {
String MachineID1 = s1.getMachineIdNumber();
String MachineID2 = s2.getMachineIdNumber();
//ascending order
return MachineID1.compareTo(MachineID2);
}};
