Javafx - Array: gerar imprimir e embaralhar

Estamos mostrando mais um excelente exemplo de uso de array em java,
desta vez, o programa gera, imprime e embaralha todos os elementos
que foram gerados utilizando a classe java.util.Random que é capaz de
gerar números aleatórios em java.
Más a graça do programa é sua bela interface com borda criada
utilizando a classe canvas que é muito boa para desenhos de figuras
geométricas como retângulos, polígonos, triângulos entre outros.
Se você está a procura de um programa com menu e caixa de diálogos,
aproveite este exemplo, e se possível compartilhe seus conhecimentos desta
 poderosa linguagem de programação conosco.

Veja abaixo imagens do programa em execução:

Veja abaixo o código do programa:

import javafx.application.Application;

import javafx.event.ActionEvent;

import javafx.event.EventHandler;

import javafx.scene.Scene;

import javafx.scene.canvas.Canvas;

import javafx.scene.canvas.GraphicsContext;

import javafx.scene.control.Alert;

import javafx.scene.control.Alert.AlertType;

import javafx.scene.control.Menu;

import javafx.scene.control.MenuBar;

import javafx.scene.control.MenuItem;

import javafx.scene.input.KeyCode;

import javafx.scene.input.KeyCodeCombination;

import javafx.scene.input.KeyCombination;

import javafx.scene.layout.BorderPane;

import javafx.scene.paint.Color;

import javafx.scene.text.Font;

import javafx.scene.text.FontWeight;

import javafx.stage.Stage;

import java.util.Random;

public class PROJETO extends Application {

     String    str             = "";

     String    str_2     = "";

     int       i, n = 100, a = 0, b = 0;

     int       vet [ ]         = new int [ n ];

     int       ve_t [ ]  = new int [ n ];

     int       x               = 0, y = 0, k = 0;

     @Override

     public void start ( Stage primaryStage ) {

          Canvas canvas = new Canvas ( 690, 500 );

          GraphicsContext ctx = canvas.getGraphicsContext2D ( );

          ctx.setFont ( Font.font ( "Arial", FontWeight.BOLD, 15 ) );

          ctx.setFill ( Color.RED );

          ctx.fillText ( "ARRAY: GERAR - IMPRIMIR E EMBARALHAR", 170, 80 );

          ctx.setLineWidth ( 22.0 );

          ctx.setStroke ( Color.GREEN );

          ctx.strokeRect ( 10, 35, 640, 420 );

          BorderPane root = new BorderPane ( );

          root.getChildren ( ).add ( canvas );

          Scene scene = new Scene ( root, 660, 465 );

          primaryStage.setScene ( scene );

          primaryStage.setTitle ( "ARRAY: GERAR - IMPRIMIR E EMBARALHAR" );

          // //////////////////////////////////////////////////////////////////////

          MenuBar m_nu_1 = new MenuBar ( );

          Menu m_nu = new Menu ( "Arq" );

          MenuItem exd = new MenuItem ( "Sair" );

          MenuItem te_d = new MenuItem ( "Imprimir" );

          m_nu.getItems ( ).addAll ( te_d, exd );

          // /////////////////////////////////////////////////

          Menu m_enu = new Menu ( "Vet" );

          MenuItem vis_vet = new MenuItem ( "Rand" );

          MenuItem vis_vet_1 = new MenuItem ( "Sobre" );

          m_enu.getItems ( ).addAll ( vis_vet, vis_vet_1 );

          // ////////////////////////////////////////////////////

          m_nu_1.getMenus ( ).add ( m_nu );

          m_nu_1.getMenus ( ).add ( m_enu );

          root.setTop ( m_nu_1 );

          // //////////////////////////////////////////////////////////////////////

          exd.setOnAction ( new EventHandler < ActionEvent > ( ) {

                @Override

                public void handle ( ActionEvent e ) {

                     primaryStage.close ( );

                }

          } );

          // //////////////////////////////////////////////////////////////////////

          te_d.setOnAction ( new EventHandler < ActionEvent > ( ) {

                @Override

                public void handle ( ActionEvent e ) {

                     ctx.setFont ( Font.font ( "Arial", FontWeight.BOLD, 15 ) );

                     ctx.setFill ( Color.BLUE );

                     ctx.fillText ( "IMPRIMINDO O ARRAY", 250, 110 );

                     if ( k == 1 ) {

                          Alert alert = new Alert ( AlertType.INFORMATION );

                          alert.setTitle ( "Atenção" );

                          alert.setHeaderText ( null );

                          alert.setContentText ( "O array já foi imprimido" );

                          alert.showAndWait ( );

                          return;

                     }

                     for ( i = 1; i <= n; i++ ) {

                          vet [ a ] = i;

                          a++;

                     }

                     for ( i = 0; i < n; i++ ) {

                          str = str + vet [ i ];

                          y = vet [ i ];

                          if ( i == 19 )

                               str += ( "\n" );

                          if ( i == 39 )

                               str += ( "\n" );

                          if ( i == 59 )

                               str += ( "\n" );

                          if ( i == 79 )

                               str += ( "\n" );

                          str += ( "  " );

                          k = 1;

                     }

                     ctx.setFill ( Color.BLACK );

                     ctx.fillText ( str, 70, 140 );

                }

          } );

          // //////////////////////////////////////////////////////////////////////

          vis_vet.setOnAction ( new EventHandler < ActionEvent > ( ) {

                @Override

                public void handle ( ActionEvent e ) {

                     if ( y == 0 ) {

                          Alert alert = new Alert ( AlertType.INFORMATION );

                          alert.setTitle ( "Atenção" );

                          alert.setHeaderText ( null );

                          alert.setContentText ( "O array ainda não foi gerado" );

                          alert.showAndWait ( );

                          return;

                     }

                     if ( x == 1 ) {

                          Alert alert = new Alert ( AlertType.INFORMATION );

                          alert.setTitle ( "Atenção" );

                          alert.setHeaderText ( null );

                          alert.setContentText ( "O array já foi embaralhado" );

                          alert.showAndWait ( );

                          return;

                     }

                     if ( y >= 0 ) {

                          x = 1;

                          ctx.setFill ( Color.BLUE );

                          ctx.fillText ( "O ARRAY FOI EMBARALHADO", 250, 240 );

                          int temp, r;

                          Random random = new Random ( );

                          for ( i = 0; i < n; i++ ) {

                               r = random.nextInt ( n );

                               temp = vet [ i ];

                               vet [ i ] = vet [ r ];

                               vet [ r ] = temp;

                          }

                          for ( r = 0; r < n; r++ ) {

                               str_2 = str_2 + vet [ r ];

                               if ( r == 19 )

                                     str_2 += ( "\n" );

                               if ( r == 39 )

                                     str_2 += ( "\n" );

                               if ( r == 59 )

                                     str_2 += ( "\n" );

                               if ( r == 79 )

                                     str_2 += ( "\n" );

                               str_2 += ( "  " );

                          }

                          ctx.setFill ( Color.BLACK );

                          ctx.fillText ( str_2, 70, 270 );

                     }

                }

          } );

          vis_vet_1.setOnAction ( new EventHandler < ActionEvent > ( ) {

                @Override

                public void handle ( ActionEvent e ) {

                     Alert alert = new Alert ( AlertType.INFORMATION );

                     alert.setTitle ( "Atenção" );

                     alert.setHeaderText ( null );

                     alert.setContentText ( "Programa criado por Samuel Lima" );

                     alert.showAndWait ( );

                }

          } );

          // //////////////////////////////////////////////////////////////////////

          exd.setAccelerator ( new KeyCodeCombination ( KeyCode.E,

                     KeyCombination.CONTROL_DOWN ) );

          te_d.setAccelerator ( new KeyCodeCombination ( KeyCode.C,

                     KeyCombination.CONTROL_DOWN ) );

          vis_vet.setAccelerator ( new KeyCodeCombination ( KeyCode.D,

                     KeyCombination.CONTROL_DOWN ) );

          vis_vet_1.setAccelerator ( new KeyCodeCombination ( KeyCode.F,

                     KeyCombination.CONTROL_DOWN ) );

          primaryStage.show ( );

     }

     public static void main ( String [ ] args ) {

          launch ( args );

     }

}