ユーザーがすべてのトラックを入力、編集、削除、および表示できるようにするモックメディアプレーヤープログラムを作成しています。かなり基本的なこと、私は知っています。しかし、音楽プレーヤーのシャッフル機能をシミュレートするために、「Play Random Song」が選択されるたびに配列リストのランダムなエントリを出力できる機能を追加したいと考えています。だから私の方法は次のようになります
public void playRandom()
{
System.out.println("Now Playing: " + *insert code here?* ")
}
トラック名、トラック年、トラック アーティストを表す 3 つの配列リストがありますが、画面に出力するときに、アーティスト、ハイフン、トラック名の順に表示するように表示したいですか?
私のコードは以下の通りです：
私のメインクラス: パッケージ ca1;
//imports the Random mechanism
import java.util.Random;
//imports the scanner
import java.util.Scanner;
public class MainClass extends UserInput {
public String nextInt;
public static void main(String[] args) {
//Links to the UserInput class to create an object that stores
//user input
UserInput ui = new UserInput();
//Creates new scanner object
Scanner input = new Scanner(System.in);
//Declares the int "opt" so it can be used in the menu
int opt;
//Calls Methods Class so methods can be used below
Methods methodsFunctions = new Methods();
//initial prompt only displayed when program is first ran
System.out.println("Welcome to your music library");
//Usig a do while loop so that the program keeps running until
//a specific condition is met, in this case it's when 0 is selected.
do
{
//Menu Prompts printed to the screen for the user to select from
System.out.println("........ \n");
System.out.println("Press 0 to Exit\n");
System.out.println("Press 1 to Add a Song\n");
System.out.println("Press 2 to View All Songs\n");
System.out.println("Press 3 to Remove a Song\n");
System.out.println("Press 4 to Edit Song Information\n");
System.out.println("Press 5 to Play Random Song\n");
System.out.println("Press 6 to Delete All Songs\n");
//Monitors the next Int the user types
opt = input.nextInt();
//"if" statements
if (opt == 0)
{
//This corresponds to the condition of the while loop,
//The program will exit and print "Goodbye!" for the user.
System.out.println("Goodbye!");
}
else if (opt == 1)
{
//This method allows the user to add a song to the library.
//With the format being Title, Artist, Year.
methodsFunctions.addEntry();
}
else if (opt == 2)
{
//This method prints the contents of the Array List to the screen
methodsFunctions.viewAll();
}
else if (opt == 3)
{
//This method allows the user to remove an indiviual song from
//their music library
methodsFunctions.removeOne();
}
else if (opt == 4)
{
//This method allows the user to edit the data of a particular
//and then prints the new value on screen
methodsFunctions.editItem();
}
else if (opt == 5)
{
//This method will print out "Now playing" followed by a random
//song to simulate a music player's shuffle effect.
//methodsFunctions.RandomSong();
System.out.println("Now Playing ");
}
else if (opt == 6)
{
//This method will clear all contents of the library.
//It will ask the user to confirm their choice.
methodsFunctions.clearAll();
}
else
{
//If the user selects an incorrect number, the console will
//tell the user to try again and the main menu will print again
System.out.println("Incorrect Entry, please try again");
}
} //do-while loop
while (opt > 0);
}
}
私のメソッドクラス:
package ca1;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import java.util.Scanner;
public class Methods extends UserInput
{
Scanner input = new Scanner (System.in);
//Declare array lists
List<String> songName = new ArrayList<>();
List<String> songArtist = new ArrayList<>();
List<Integer> songYear = new ArrayList<>();
UserInput ui = new UserInput();
private Random newRandom;
public void clearAll(){
System.out.println("Are you sure?");
System.out.print("1: Yes \n2: No" + "\n");
System.out.print("");
int confirmDelete=input.nextInt();
if (confirmDelete == 1){
songName.clear();
songYear.clear();
System.out.println("Your music library has been cleared");
}
}
public void viewAll(){
System.out.println("\n");
for (int i = 0; i < songName.size(); i++){
int counter=i+1;
System.out.println(counter+": "+songArtist.get(i)+" - "+ songName.get(i)+ " (" +songYear.get(i)+") ");
}
System.out.println("\n");
}
public void addEntry(){
//System.out.print("Enter Name: ");
String newName = ui.getString("Enter the name of the track");
songName.add(newName);
String newArtist = ui.getString("Who performs this track");
songArtist.add(newArtist);
System.out.print("What year was the track released? ");
int newYear=input.nextInt();
songYear.add(newYear);
System.out.println("\n" + "Thank you, " +songName.get(songName.size()-1) + " has been added to the library.");
System.out.println("\n" + "Press 2 to view your library." + "\n");
/*
System.out.println("\n"+songName.get(songName.size()-1));
System.out.println("\n"+songArtist.get(songArtist.size()-1));
System.out.println("\n"+songYear.get(songYear.size()-1));
*/
}
public void removeOne(){
System.out.println(" Which song would you like to delete? (1 to "+songName.size()+")");
viewAll();
int remove=input.nextInt();
if (remove >songName.size()){
System.out.println("Invalid ");
}
else {
remove--;
System.out.println("Are you sure you would like to delete "+songArtist.get(remove)+" - "+songName.get(remove)+" (" +songYear.get(remove)+ ") from your music library?");
System.out.print("1: Yes \n2: No" + "\n");
int confirmDelete=input.nextInt();
if (confirmDelete == 1){
songArtist.remove(remove);
songName.remove(remove);
songYear.remove(remove);
System.out.println(songName.get(remove)+ " has just been removed from your music library");
// viewAll();
}
}
}
public void playRandom()
{
String RandomSong = (SongName.random);
System.out("Now playing + " RandomSong);
}
public void editItem(){
viewAll();
System.out.println("Choose the song you want to edit (1 to "+songName.size()+")");
//prints out the contents of library with first entry being index 1
//The library is numbered and goes as far as the index of the last entry
int edit=input.nextInt();
if (edit >songName.size()){
System.out.println("Invalid Selection");
//if user selects a number that corresponds to an index that's not
//In the array list, they will be shown an error.
}
else{
edit--;
System.out.println("\n" + "Enter New Track Name: ");
input.nextLine();
String editName=input.nextLine();
songName.set(edit,editName);
//Edits the songName value of the Song object selected
System.out.println("\n" + "Enter New Artist ");
String editArtist=input.nextLine();
songArtist.set(edit,editArtist);
//Edits the songArtist value of the Song object selected
System.out.println("\n" + "Enter New Year:");
int editYear;
editYear = input.nextInt();
songYear.set(edit,editYear);
//Edits the songName value of the Song object selected
System.out.print("\n" + "Your changes have been saved:" + "\n");
System.out.print("\n" + "This is your current library");
viewAll();
}
}
}