Добавление JPanels в JFrame?

Question

Цикл while в моем коде ниже не отображает JPanels в графическом интерфейсе. Каков правильный способ сделать это? Я ценю помощь. Не беспокойтесь о том, что делает код.

import java.io.File; 
import java.io.FileNotFoundException; 
import java.util.Scanner; 

import javax.swing.*; 

public class Green {   

public static int[] values = new int[100]; 
public final int COLOR_RANGE = 150; 
public static int count; 

JFrame window = new JFrame("Green Values"); 
static JPanel main_panel = new JPanel(); 
static JPanel green_panel; 

public Green() { 

    window.setSize(600, 600); 
    window.setVisible(true); 
    main_panel.setVisible(true); 
    window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
    window.pack(); 
} 

public static void main (String[] args) throws FileNotFoundException { 

Green g = new Green(); 

Scanner sc = new Scanner(new File("green.txt")); 

int i = 0; 
while(sc.hasNextInt()) { 
    values[i++] = sc.nextInt();   
    count++;  
    JPanel green_panel = new JPanel();  // help 
    main_panel.add(green_panel);   // help - is this correct? 

sc.close(); 

    int max = values[0]; 
    int min = values[0]; 
    for (i = 0; i < count; i++) { 
     if (max < values[i]) { 
      max = values[i]; 
     } 
     if (min > values[i]) { 
      min = values[i]; 
     } 
    } 

    int temp; 
    int val = 0; 

    for (i = 0; i < count; i++) { 
     values[i] = val; 
     System.out.println("Array value: " + val + " | " + "Green value: " +  g.greenValue(val, max, min)); 
     temp = values[i+1]; 
     val = temp; 
     } 
} 
} 

public int greenValue(int val, int max, int min) { 

    int colorValue; 
    int arrayRange = (max - min); 
    colorValue = (((val-min) * COLOR_RANGE)/arrayRange) + 100; 

    return colorValue; 
} 

} 

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Answer 1

Каков правильный способ сделать это?

1. Избегайте static, это не поможет вам в долгосрочной перспективе
2. Добавить main_panel к раме

Может быть что-то больше похоже на ...

import java.awt.EventQueue; 
import java.io.File; 
import java.io.FileNotFoundException; 
import java.util.Scanner; 
import javax.swing.JComponent; 
import javax.swing.JFrame; 
import javax.swing.JPanel; 
import javax.swing.UIManager; 
import javax.swing.UnsupportedLookAndFeelException; 

public class Green { 

    public static int[] values = new int[100]; 
    public final int COLOR_RANGE = 150; 
    public static int count; 

    JFrame window = new JFrame("Green Values"); 
    JPanel main_panel = new JPanel(); 
    JPanel green_panel; 

    public Green() { 

     window.setSize(600, 600); 
     window.add(main_panel); 
     window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     window.pack(); 
     window.setVisible(true); 

    } 

    public void add(JComponent comp) { 
     main_panel.add(comp); 
     main_panel.revalidate(); 
     main_panel.repaint(); 
    } 

    public static void main(String[] args) { 
     EventQueue.invokeLater(new Runnable() { 
      @Override 
      public void run() { 
       try { 
        UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName()); 
       } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) { 
        ex.printStackTrace(); 
       } 

       Green g = new Green(); 

       try { 
        Scanner sc = new Scanner(new File("green.txt")); 

        int i = 0; 
        while (sc.hasNextInt()) { 
         values[i++] = sc.nextInt(); 
         count++; 
         JPanel green_panel = new JPanel();  // help 
         g.add(green_panel);   // help - is this correct? 

         sc.close(); 

         int max = values[0]; 
         int min = values[0]; 
         for (i = 0; i < count; i++) { 
          if (max < values[i]) { 
           max = values[i]; 
          } 
          if (min > values[i]) { 
           min = values[i]; 
          } 
         } 

         int temp; 
         int val = 0; 

         for (i = 0; i < count; i++) { 
          values[i] = val; 
          System.out.println("Array value: " + val + " | " + "Green value: " + g.greenValue(val, max, min)); 
          temp = values[i + 1]; 
          val = temp; 
         } 
        } 
       } catch (FileNotFoundException exp) { 
        exp.printStackTrace(); 
       } 
      } 
     }); 

    } 

    public int greenValue(int val, int max, int min) { 

     int colorValue; 
     int arrayRange = (max - min); 
     colorValue = (((val - min) * COLOR_RANGE)/arrayRange) + 100; 

     return colorValue; 
    } 

}